From a1adb6fd02a6557b7b96363ba973477b319d824a Mon Sep 17 00:00:00 2001
From: Jaroslav Hanslik <kukulich@kukulich.cz>
Date: Fri, 14 Aug 2015 21:52:40 +0200
Subject: [PATCH] PHP7 scalar and return type hints support

---
 .travis.yml                                   |  3 +-
 composer.json                                 |  2 +-
 src/Iterators/CachingIterator.php             | 24 +++---
 src/Iterators/Mapper.php                      |  2 +
 src/Utils/ArrayHash.php                       | 10 ++-
 src/Utils/ArrayList.php                       |  6 +-
 src/Utils/Arrays.php                          | 12 +--
 src/Utils/Callback.php                        | 16 ++--
 src/Utils/DateTime.php                        | 12 +--
 src/Utils/FileSystem.php                      | 14 ++--
 src/Utils/Html.php                            | 60 +++++++--------
 src/Utils/IHtmlString.php                     |  4 +-
 src/Utils/ITranslator.php                     |  4 +-
 src/Utils/Image.php                           | 42 ++++++-----
 src/Utils/Json.php                            |  6 +-
 src/Utils/Object.php                          | 14 ++--
 src/Utils/ObjectMixin.php                     | 26 ++++---
 src/Utils/Paginator.php                       | 34 +++++----
 src/Utils/Random.php                          |  4 +-
 src/Utils/Strings.php                         | 74 ++++++++++---------
 src/Utils/Validators.php                      | 34 +++++----
 src/Utils/exceptions.php                      |  2 +
 tests/Iterators/CachingIterator.basic.phpt    |  2 +
 .../Iterators/CachingIterator.construct.phpt  |  2 +
 tests/Iterators/CachingIterator.width.phpt    |  2 +
 tests/Iterators/Mapper.phpt                   |  2 +
 tests/Utils/ArrayHash.phpt                    |  2 +
 tests/Utils/ArrayList.phpt                    |  2 +
 tests/Utils/Arrays.associate().error.phpt     |  2 +
 tests/Utils/Arrays.associate().phpt           |  2 +
 tests/Utils/Arrays.flatten().phpt             |  2 +
 tests/Utils/Arrays.get().phpt                 |  2 +
 tests/Utils/Arrays.getRef().phpt              |  2 +
 tests/Utils/Arrays.grep().errors.phpt         |  2 +
 tests/Utils/Arrays.grep().phpt                |  2 +
 tests/Utils/Arrays.insertBefore().phpt        |  2 +
 tests/Utils/Arrays.isList.phpt                |  2 +
 tests/Utils/Arrays.normalize.phpt             |  2 +
 tests/Utils/Arrays.pick().phpt                |  2 +
 tests/Utils/Arrays.renameKey().phpt           |  2 +
 tests/Utils/Arrays.searchKey().phpt           |  2 +
 tests/Utils/Callback.check.phpt               |  2 +
 tests/Utils/Callback.closure.phpt             |  2 +
 tests/Utils/Callback.invoke.phpt              |  2 +
 tests/Utils/Callback.invokeSafe.phpt          |  2 +
 tests/Utils/DateTime.JSON.phpt                |  2 +
 tests/Utils/DateTime.createFromFormat.phpt    |  2 +
 tests/Utils/DateTime.from.phpt                |  2 +
 tests/Utils/FileSystem.phpt                   |  2 +
 tests/Utils/Html.basic.phpt                   |  2 +
 tests/Utils/Html.children.phpt                |  2 +
 tests/Utils/Html.construct.phpt               |  2 +
 tests/Utils/Html.data.phpt                    |  2 +
 tests/Utils/Html.style.phpt                   |  2 +
 tests/Utils/Image.alpha1.phpt                 |  2 +
 tests/Utils/Image.clone.phpt                  |  2 +
 tests/Utils/Image.drawing.phpt                |  2 +
 tests/Utils/Image.factories.phpt              |  2 +
 tests/Utils/Image.resize.phpt                 |  2 +
 tests/Utils/Image.save.phpt                   |  2 +
 tests/Utils/Image.send.phpt                   |  2 +
 tests/Utils/Json.decode().phpt                |  2 +
 tests/Utils/Json.encode().phpt                |  2 +
 tests/Utils/Object.arrayProperty.phpt         |  2 +
 tests/Utils/Object.closureProperty.phpt       |  2 +
 tests/Utils/Object.events.phpt                |  2 +
 tests/Utils/Object.extensionMethod.phpt       |  2 +
 .../Object.extensionMethodViaInterface.phpt   |  2 +
 tests/Utils/Object.magicMethod.errors.phpt    |  2 +
 .../Utils/Object.magicMethod.inheritance.phpt |  2 +
 tests/Utils/Object.magicMethod.phpt           |  2 +
 tests/Utils/Object.magicMethod.types.phpt     |  2 +
 tests/Utils/Object.methodGetter.phpt          |  2 +
 tests/Utils/Object.property.phpt              |  2 +
 tests/Utils/Object.referenceProperty.phpt     |  2 +
 tests/Utils/Object.reflection.phpt            |  2 +
 tests/Utils/Object.undeclaredMethod.phpt      |  2 +
 tests/Utils/Object.unsetProperty.phpt         |  2 +
 tests/Utils/ObjectMixin.checkType().phpt      |  2 +
 tests/Utils/Paginator.phpt                    |  2 +
 tests/Utils/Random.generate().no-mcrypt.phpt  |  2 +
 tests/Utils/Random.generate().no-openssl.phpt |  2 +
 tests/Utils/Random.generate().phpt            |  2 +
 .../Strings.Regexp.errors.backtrack.phpt      |  2 +
 .../Strings.Regexp.errors.compilation.phpt    |  2 +
 tests/Utils/Strings.Regexp.errors.utf8.phpt   |  2 +
 tests/Utils/Strings.after().phpt              |  2 +
 tests/Utils/Strings.before().phpt             |  2 +
 tests/Utils/Strings.checkEncoding().phpt      |  2 +
 tests/Utils/Strings.chr().phpt                |  2 +
 tests/Utils/Strings.compare().phpt            |  2 +
 tests/Utils/Strings.convertCase.phpt          |  2 +
 tests/Utils/Strings.endsWith().phpt           |  6 +-
 tests/Utils/Strings.findPrefix().phpt         |  2 +
 tests/Utils/Strings.fixEncoding().phpt        |  2 +
 tests/Utils/Strings.indent().phpt             |  2 +
 tests/Utils/Strings.indexOf().phpt            |  2 +
 tests/Utils/Strings.length().phpt             |  2 +
 tests/Utils/Strings.match().phpt              |  2 +
 tests/Utils/Strings.matchAll().phpt           |  2 +
 tests/Utils/Strings.normalize().phpt          |  2 +
 tests/Utils/Strings.normalizeNewLines().phpt  |  2 +
 tests/Utils/Strings.pad.phpt                  |  2 +
 tests/Utils/Strings.random().phpt             |  2 +
 .../Strings.replace().errors.callback.phpt    |  2 +
 tests/Utils/Strings.replace().php53.phpt      |  2 +
 tests/Utils/Strings.replace().phpt            |  2 +
 tests/Utils/Strings.reverse().phpt            |  2 +
 tests/Utils/Strings.split().phpt              |  2 +
 tests/Utils/Strings.startsWith().phpt         |  6 +-
 tests/Utils/Strings.substring().phpt          |  2 +
 tests/Utils/Strings.toAscii().phpt            |  2 +
 tests/Utils/Strings.trim().phpt               |  2 +
 tests/Utils/Strings.truncate().phpt           |  2 +
 tests/Utils/Strings.webalize().phpt           |  2 +
 tests/Utils/Validators.assert().phpt          |  2 +
 tests/Utils/Validators.assertField().phpt     |  2 +
 tests/Utils/Validators.is().phpt              |  2 +
 tests/Utils/Validators.isInRange().phpt       |  2 +
 tests/bootstrap.php                           |  2 +
 120 files changed, 424 insertions(+), 185 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index dd0439bd0..ac14ed078 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,5 @@
 language: php
 php:
-    - 5.6
     - 7.0
     - hhvm
 
@@ -20,7 +19,7 @@ before_script:
     # Install Nette Tester & Code Checker
     - travis_retry composer install --no-interaction --prefer-dist
     - travis_retry composer create-project nette/code-checker temp/code-checker ~2.5 --no-interaction
-  
+
 sudo: false
 
 cache:
diff --git a/composer.json b/composer.json
index 900673207..038692466 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
 		}
 	],
 	"require": {
-		"php": ">=5.6.0"
+		"php": ">=7.0.0"
 	},
 	"require-dev": {
 		"nette/tester": "~1.0"
diff --git a/src/Iterators/CachingIterator.php b/src/Iterators/CachingIterator.php
index 9d25e5216..5b9e9f66e 100644
--- a/src/Iterators/CachingIterator.php
+++ b/src/Iterators/CachingIterator.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Iterators;
 
 use Nette;
@@ -56,7 +58,7 @@ public function __construct($iterator)
 	 * @param  int  grid width
 	 * @return bool
 	 */
-	public function isFirst($width = NULL)
+	public function isFirst(int $width = NULL): bool
 	{
 		return $this->counter === 1 || ($width && $this->counter !== 0 && (($this->counter - 1) % $width) === 0);
 	}
@@ -67,7 +69,7 @@ public function isFirst($width = NULL)
 	 * @param  int  grid width
 	 * @return bool
 	 */
-	public function isLast($width = NULL)
+	public function isLast(int $width = NULL): bool
 	{
 		return !$this->hasNext() || ($width && ($this->counter % $width) === 0);
 	}
@@ -77,7 +79,7 @@ public function isLast($width = NULL)
 	 * Is the iterator empty?
 	 * @return bool
 	 */
-	public function isEmpty()
+	public function isEmpty(): bool
 	{
 		return $this->counter === 0;
 	}
@@ -87,7 +89,7 @@ public function isEmpty()
 	 * Is the counter odd?
 	 * @return bool
 	 */
-	public function isOdd()
+	public function isOdd(): bool
 	{
 		return $this->counter % 2 === 1;
 	}
@@ -97,7 +99,7 @@ public function isOdd()
 	 * Is the counter even?
 	 * @return bool
 	 */
-	public function isEven()
+	public function isEven(): bool
 	{
 		return $this->counter % 2 === 0;
 	}
@@ -107,7 +109,7 @@ public function isEven()
 	 * Returns the counter.
 	 * @return int
 	 */
-	public function getCounter()
+	public function getCounter(): int
 	{
 		return $this->counter;
 	}
@@ -117,7 +119,7 @@ public function getCounter()
 	 * Returns the count of elements.
 	 * @return int
 	 */
-	public function count()
+	public function count(): int
 	{
 		$inner = $this->getInnerIterator();
 		if ($inner instanceof \Countable) {
@@ -195,7 +197,7 @@ public function __call($name, $args)
 	 * @return mixed   property value
 	 * @throws Nette\MemberAccessException if the property is not defined.
 	 */
-	public function &__get($name)
+	public function &__get(string $name)
 	{
 		return ObjectMixin::get($this, $name);
 	}
@@ -208,7 +210,7 @@ public function &__get($name)
 	 * @return void
 	 * @throws Nette\MemberAccessException if the property is not defined or is read-only
 	 */
-	public function __set($name, $value)
+	public function __set(string $name, $value)
 	{
 		ObjectMixin::set($this, $name, $value);
 	}
@@ -219,7 +221,7 @@ public function __set($name, $value)
 	 * @param  string  property name
 	 * @return bool
 	 */
-	public function __isset($name)
+	public function __isset(string $name): bool
 	{
 		return ObjectMixin::has($this, $name);
 	}
@@ -231,7 +233,7 @@ public function __isset($name)
 	 * @return void
 	 * @throws Nette\MemberAccessException
 	 */
-	public function __unset($name)
+	public function __unset(string $name)
 	{
 		ObjectMixin::remove($this, $name);
 	}
diff --git a/src/Iterators/Mapper.php b/src/Iterators/Mapper.php
index 16f1faf28..f849c21d6 100644
--- a/src/Iterators/Mapper.php
+++ b/src/Iterators/Mapper.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Iterators;
 
 use Nette;
diff --git a/src/Utils/ArrayHash.php b/src/Utils/ArrayHash.php
index 1e00bbb8b..212febdaf 100644
--- a/src/Utils/ArrayHash.php
+++ b/src/Utils/ArrayHash.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -19,9 +21,9 @@ class ArrayHash extends \stdClass implements \ArrayAccess, \Countable, \Iterator
 	/**
 	 * @param  array to wrap
 	 * @param  bool
-	 * @return self
+	 * @return static
 	 */
-	public static function from($arr, $recursive = TRUE)
+	public static function from(array $arr, bool $recursive = TRUE): self
 	{
 		$obj = new static;
 		foreach ($arr as $key => $value) {
@@ -39,7 +41,7 @@ public static function from($arr, $recursive = TRUE)
 	 * Returns an iterator over all items.
 	 * @return \RecursiveArrayIterator
 	 */
-	public function getIterator()
+	public function getIterator(): \RecursiveArrayIterator
 	{
 		return new \RecursiveArrayIterator($this);
 	}
@@ -49,7 +51,7 @@ public function getIterator()
 	 * Returns items count.
 	 * @return int
 	 */
-	public function count()
+	public function count(): int
 	{
 		return count((array) $this);
 	}
diff --git a/src/Utils/ArrayList.php b/src/Utils/ArrayList.php
index 056eac232..e5bfeea81 100644
--- a/src/Utils/ArrayList.php
+++ b/src/Utils/ArrayList.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -22,7 +24,7 @@ class ArrayList extends Nette\Object implements \ArrayAccess, \Countable, \Itera
 	 * Returns an iterator over all items.
 	 * @return \ArrayIterator
 	 */
-	public function getIterator()
+	public function getIterator(): \ArrayIterator
 	{
 		return new \ArrayIterator($this->list);
 	}
@@ -32,7 +34,7 @@ public function getIterator()
 	 * Returns items count.
 	 * @return int
 	 */
-	public function count()
+	public function count(): int
 	{
 		return count($this->list);
 	}
diff --git a/src/Utils/Arrays.php b/src/Utils/Arrays.php
index 547d91331..67db65fe9 100644
--- a/src/Utils/Arrays.php
+++ b/src/Utils/Arrays.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -73,7 +75,7 @@ public static function & getRef(array & $arr, $key)
 	 * Recursively appends elements of remaining keys from the second array to the first.
 	 * @return array
 	 */
-	public static function mergeTree(array $arr1, array $arr2)
+	public static function mergeTree(array $arr1, array $arr2): array
 	{
 		$res = $arr1 + $arr2;
 		foreach (array_intersect_key($arr1, $arr2) as $k => $v) {
@@ -138,7 +140,7 @@ public static function renameKey(array & $arr, $oldKey, $newKey)
 	 * Returns array entries that match the pattern.
 	 * @return array
 	 */
-	public static function grep(array $arr, $pattern, $flags = 0)
+	public static function grep(array $arr, string $pattern, int $flags = 0): array
 	{
 		return Strings::pcre('preg_grep', [$pattern, $arr, $flags]);
 	}
@@ -148,7 +150,7 @@ public static function grep(array $arr, $pattern, $flags = 0)
 	 * Returns flattened array.
 	 * @return array
 	 */
-	public static function flatten(array $arr, $preserveKeys = FALSE)
+	public static function flatten(array $arr, bool $preserveKeys = FALSE): array
 	{
 		$res = [];
 		$cb = $preserveKeys
@@ -163,7 +165,7 @@ public static function flatten(array $arr, $preserveKeys = FALSE)
 	 * Finds whether a variable is a zero-based integer indexed array.
 	 * @return bool
 	 */
-	public static function isList($value)
+	public static function isList($value): bool
 	{
 		return is_array($value) && (!$value || array_keys($value) === range(0, count($value) - 1));
 	}
@@ -225,7 +227,7 @@ public static function associate(array $arr, $path)
 	 * Normalizes to associative array.
 	 * @return array
 	 */
-	public static function normalize(array $arr, $filling = NULL)
+	public static function normalize(array $arr, $filling = NULL): array
 	{
 		$res = [];
 		foreach ($arr as $k => $v) {
diff --git a/src/Utils/Callback.php b/src/Utils/Callback.php
index 40c763cd1..d0eac6692 100644
--- a/src/Utils/Callback.php
+++ b/src/Utils/Callback.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -21,7 +23,7 @@ class Callback
 	 * @param  string  method
 	 * @return \Closure
 	 */
-	public static function closure($callable, $m = NULL)
+	public static function closure($callable, string $m = NULL): \Closure
 	{
 		if ($m !== NULL) {
 			$callable = [$callable, $m];
@@ -78,9 +80,9 @@ public static function invokeArgs($callable, array $args = [])
 	 * @param  string
 	 * @return mixed
 	 */
-	public static function invokeSafe($function, array $args, $onError)
+	public static function invokeSafe(string $function, array $args, $onError)
 	{
-		$prev = set_error_handler(function ($severity, $message, $file) use ($onError, & $prev, $function) {
+		$prev = set_error_handler(function (int $severity, string $message, string $file) use ($onError, & $prev, $function) {
 			if ($file === '' && defined('HHVM_VERSION')) { // https://github.com/facebook/hhvm/issues/4625
 				$file = func_get_arg(5)[1]['file'];
 			}
@@ -108,7 +110,7 @@ public static function invokeSafe($function, array $args, $onError)
 	/**
 	 * @return callable
 	 */
-	public static function check($callable, $syntax = FALSE)
+	public static function check($callable, bool $syntax = FALSE)
 	{
 		if (!is_callable($callable, $syntax)) {
 			throw new Nette\InvalidArgumentException($syntax
@@ -123,7 +125,7 @@ public static function check($callable, $syntax = FALSE)
 	/**
 	 * @return string
 	 */
-	public static function toString($callable)
+	public static function toString($callable): string
 	{
 		if ($callable instanceof \Closure) {
 			$inner = self::unwrap($callable);
@@ -166,7 +168,7 @@ public static function toReflection($callable)
 	/**
 	 * @return bool
 	 */
-	public static function isStatic($callable)
+	public static function isStatic($callable): bool
 	{
 		return is_array($callable) ? is_string($callable[0]) : is_string($callable);
 	}
@@ -177,7 +179,7 @@ public static function isStatic($callable)
 	 * @internal
 	 * @return callable
 	 */
-	public static function unwrap(\Closure $closure)
+	public static function unwrap(\Closure $closure): callable
 	{
 		$r = new \ReflectionFunction($closure);
 		if (substr($r->getName(), -1) === '}') {
diff --git a/src/Utils/DateTime.php b/src/Utils/DateTime.php
index f87efa5a7..6ebe8a60f 100644
--- a/src/Utils/DateTime.php
+++ b/src/Utils/DateTime.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -39,7 +41,7 @@ class DateTime extends \DateTime implements \JsonSerializable
 	 * @param  string|int|\DateTimeInterface
 	 * @return self
 	 */
-	public static function from($time)
+	public static function from($time): self
 	{
 		if ($time instanceof \DateTimeInterface) {
 			return new static($time->format('Y-m-d H:i:s'), $time->getTimezone());
@@ -59,7 +61,7 @@ public static function from($time)
 	/**
 	 * @return string
 	 */
-	public function __toString()
+	public function __toString(): string
 	{
 		return $this->format('Y-m-d H:i:s');
 	}
@@ -69,7 +71,7 @@ public function __toString()
 	 * @param  string
 	 * @return self
 	 */
-	public function modifyClone($modify = '')
+	public function modifyClone(string $modify = ''): self
 	{
 		$dolly = clone $this;
 		return $modify ? $dolly->modify($modify) : $dolly;
@@ -80,7 +82,7 @@ public function modifyClone($modify = '')
 	 * @param  int
 	 * @return self
 	 */
-	public function setTimestamp($timestamp)
+	public function setTimestamp($timestamp): self
 	{
 		$zone = $this->getTimezone();
 		$this->__construct('@' . $timestamp);
@@ -126,7 +128,7 @@ public static function createFromFormat($format, $time, $timezone = NULL)
 	 * Returns JSON representation in ISO 8601 (used by JavaScript).
 	 * @return string
 	 */
-	public function jsonSerialize()
+	public function jsonSerialize(): string
 	{
 		return $this->format('c');
 	}
diff --git a/src/Utils/FileSystem.php b/src/Utils/FileSystem.php
index 62d9ad769..4d0b739f0 100644
--- a/src/Utils/FileSystem.php
+++ b/src/Utils/FileSystem.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -21,7 +23,7 @@ class FileSystem
 	 * @return void
 	 * @throws Nette\IOException
 	 */
-	public static function createDir($dir, $mode = 0777)
+	public static function createDir(string $dir, int $mode = 0777)
 	{
 		if (!is_dir($dir) && !@mkdir($dir, $mode, TRUE)) { // intentionally @; not atomic
 			throw new Nette\IOException("Unable to create directory '$dir'.");
@@ -34,7 +36,7 @@ public static function createDir($dir, $mode = 0777)
 	 * @return void
 	 * @throws Nette\IOException
 	 */
-	public static function copy($source, $dest, $overwrite = TRUE)
+	public static function copy(string $source, string $dest, bool $overwrite = TRUE)
 	{
 		if (stream_is_local($source) && !file_exists($source)) {
 			throw new Nette\IOException("File or directory '$source' not found.");
@@ -69,7 +71,7 @@ public static function copy($source, $dest, $overwrite = TRUE)
 	 * @return void
 	 * @throws Nette\IOException
 	 */
-	public static function delete($path)
+	public static function delete(string $path)
 	{
 		if (is_file($path) || is_link($path)) {
 			$func = DIRECTORY_SEPARATOR === '\\' && is_dir($path) ? 'rmdir' : 'unlink';
@@ -94,7 +96,7 @@ public static function delete($path)
 	 * @throws Nette\IOException
 	 * @throws Nette\InvalidStateException if the target file or directory already exist
 	 */
-	public static function rename($name, $newName, $overwrite = TRUE)
+	public static function rename(string $name, string $newName, bool $overwrite = TRUE)
 	{
 		if (!$overwrite && file_exists($newName)) {
 			throw new Nette\InvalidStateException("File or directory '$newName' already exists.");
@@ -117,7 +119,7 @@ public static function rename($name, $newName, $overwrite = TRUE)
 	 * @return void
 	 * @throws Nette\IOException
 	 */
-	public static function write($file, $content, $mode = 0666)
+	public static function write(string $file, $content, int $mode = 0666)
 	{
 		static::createDir(dirname($file));
 		if (@file_put_contents($file, $content) === FALSE) { // @ is escalated to exception
@@ -133,7 +135,7 @@ public static function write($file, $content, $mode = 0666)
 	 * Is path absolute?
 	 * @return bool
 	 */
-	public static function isAbsolute($path)
+	public static function isAbsolute(string $path): bool
 	{
 		return (bool) preg_match('#([a-z]:)?[/\\\\]|[a-z][a-z0-9+.-]*://#Ai', $path);
 	}
diff --git a/src/Utils/Html.php b/src/Utils/Html.php
index 1388bb62f..3a120f80e 100644
--- a/src/Utils/Html.php
+++ b/src/Utils/Html.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -52,7 +54,7 @@ class Html extends Nette\Object implements \ArrayAccess, \Countable, \IteratorAg
 	 * @param  array|string element's attributes or plain text content
 	 * @return self
 	 */
-	public static function el($name = NULL, $attrs = NULL)
+	public static function el(string $name = NULL, $attrs = NULL): self
 	{
 		$el = new static;
 		$parts = explode(' ', (string) $name, 2);
@@ -82,7 +84,7 @@ public static function el($name = NULL, $attrs = NULL)
 	 * @return self
 	 * @throws Nette\InvalidArgumentException
 	 */
-	public function setName($name, $isEmpty = NULL)
+	public function setName(string $name, bool $isEmpty = NULL): self
 	{
 		if ($name !== NULL && !is_string($name)) {
 			throw new Nette\InvalidArgumentException(sprintf('Name must be string or NULL, %s given.', gettype($name)));
@@ -98,7 +100,7 @@ public function setName($name, $isEmpty = NULL)
 	 * Returns element's name.
 	 * @return string
 	 */
-	public function getName()
+	public function getName(): string
 	{
 		return $this->name;
 	}
@@ -108,7 +110,7 @@ public function getName()
 	 * Is element empty?
 	 * @return bool
 	 */
-	public function isEmpty()
+	public function isEmpty(): bool
 	{
 		return $this->isEmpty;
 	}
@@ -119,7 +121,7 @@ public function isEmpty()
 	 * @param  array
 	 * @return self
 	 */
-	public function addAttributes(array $attrs)
+	public function addAttributes(array $attrs): self
 	{
 		$this->attrs = array_merge($this->attrs, $attrs);
 		return $this;
@@ -132,7 +134,7 @@ public function addAttributes(array $attrs)
 	 * @param  mixed     HTML attribute value
 	 * @return void
 	 */
-	public function __set($name, $value)
+	public function __set(string $name, $value)
 	{
 		$this->attrs[$name] = $value;
 	}
@@ -143,7 +145,7 @@ public function __set($name, $value)
 	 * @param  string    HTML attribute name
 	 * @return mixed     HTML attribute value
 	 */
-	public function &__get($name)
+	public function &__get(string $name)
 	{
 		return $this->attrs[$name];
 	}
@@ -154,7 +156,7 @@ public function &__get($name)
 	 * @param  string    HTML attribute name
 	 * @return bool
 	 */
-	public function __isset($name)
+	public function __isset(string $name): bool
 	{
 		return isset($this->attrs[$name]);
 	}
@@ -165,7 +167,7 @@ public function __isset($name)
 	 * @param  string    HTML attribute name
 	 * @return void
 	 */
-	public function __unset($name)
+	public function __unset(string $name)
 	{
 		unset($this->attrs[$name]);
 	}
@@ -177,7 +179,7 @@ public function __unset($name)
 	 * @param  array   (string) HTML attribute value or pair?
 	 * @return mixed
 	 */
-	public function __call($m, $args)
+	public function __call(string $m, array $args)
 	{
 		$p = substr($m, 0, 3);
 		if ($p === 'get' || $p === 'set' || $p === 'add') {
@@ -216,7 +218,7 @@ public function __call($m, $args)
 	 * @param  array query
 	 * @return self
 	 */
-	public function href($path, $query = NULL)
+	public function href(string $path, array $query = NULL): self
 	{
 		if ($query) {
 			$query = http_build_query($query, '', '&');
@@ -233,7 +235,7 @@ public function href($path, $query = NULL)
 	 * Setter for data-* attributes. Booleans are converted to 'true' resp. 'false'.
 	 * @return self
 	 */
-	public function data($name, $value = NULL)
+	public function data(string $name, $value = NULL): self
 	{
 		if (func_num_args() === 1) {
 			$this->attrs['data'] = $name;
@@ -250,13 +252,13 @@ public function data($name, $value = NULL)
 	 * @return self
 	 * @throws Nette\InvalidArgumentException
 	 */
-	public function setHtml($html)
+	public function setHtml(string $html): self
 	{
 		if (is_array($html)) {
 			throw new Nette\InvalidArgumentException(sprintf('Textual content must be a scalar, %s given.', gettype($html)));
 		}
 		$this->removeChildren();
-		$this->children[] = (string) $html;
+		$this->children[] = $html;
 		return $this;
 	}
 
@@ -265,7 +267,7 @@ public function setHtml($html)
 	 * Returns element's HTML content.
 	 * @return string
 	 */
-	public function getHtml()
+	public function getHtml(): string
 	{
 		$s = '';
 		foreach ($this->children as $child) {
@@ -281,11 +283,11 @@ public function getHtml()
 
 	/**
 	 * Sets element's textual content.
-	 * @param  string
+	 * @param  mixed
 	 * @return self
 	 * @throws Nette\InvalidArgumentException
 	 */
-	public function setText($text)
+	public function setText($text): self
 	{
 		if (!is_array($text) && !$text instanceof self) {
 			$text = htmlspecialchars((string) $text, ENT_NOQUOTES, 'UTF-8');
@@ -298,7 +300,7 @@ public function setText($text)
 	 * Returns element's textual content.
 	 * @return string
 	 */
-	public function getText()
+	public function getText(): string
 	{
 		return html_entity_decode(strip_tags($this->getHtml()), ENT_QUOTES, 'UTF-8');
 	}
@@ -309,7 +311,7 @@ public function getText()
 	 * @param  Html|string Html node or raw HTML string
 	 * @return self
 	 */
-	public function add($child)
+	public function add($child): self
 	{
 		return $this->insert(NULL, $child);
 	}
@@ -321,7 +323,7 @@ public function add($child)
 	 * @param  array|string element's attributes or raw HTML string
 	 * @return self  created element
 	 */
-	public function create($name, $attrs = NULL)
+	public function create(string $name, $attrs = NULL): self
 	{
 		$this->insert(NULL, $child = static::el($name, $attrs));
 		return $child;
@@ -336,7 +338,7 @@ public function create($name, $attrs = NULL)
 	 * @return self
 	 * @throws Nette\InvalidArgumentException
 	 */
-	public function insert($index, $child, $replace = FALSE)
+	public function insert($index, $child, bool $replace = FALSE): self
 	{
 		if ($child instanceof self || is_scalar($child)) {
 			if ($index === NULL) { // append
@@ -405,7 +407,7 @@ public function offsetUnset($index)
 	 * Returns children count.
 	 * @return int
 	 */
-	public function count()
+	public function count(): int
 	{
 		return count($this->children);
 	}
@@ -425,7 +427,7 @@ public function removeChildren()
 	 * Iterates over a elements.
 	 * @return \ArrayIterator
 	 */
-	public function getIterator()
+	public function getIterator(): \ArrayIterator
 	{
 		return new \ArrayIterator($this->children);
 	}
@@ -435,7 +437,7 @@ public function getIterator()
 	 * Returns all of children.
 	 * @return array
 	 */
-	public function getChildren()
+	public function getChildren(): array
 	{
 		return $this->children;
 	}
@@ -446,7 +448,7 @@ public function getChildren()
 	 * @param  int
 	 * @return string
 	 */
-	public function render($indent = NULL)
+	public function render(int $indent = NULL): string
 	{
 		$s = $this->startTag();
 
@@ -474,7 +476,7 @@ public function render($indent = NULL)
 	}
 
 
-	public function __toString()
+	public function __toString(): string
 	{
 		return $this->render();
 	}
@@ -484,7 +486,7 @@ public function __toString()
 	 * Returns element's start tag.
 	 * @return string
 	 */
-	public function startTag()
+	public function startTag(): string
 	{
 		if ($this->name) {
 			return '<' . $this->name . $this->attributes() . (static::$xhtml && $this->isEmpty ? ' />' : '>');
@@ -499,7 +501,7 @@ public function startTag()
 	 * Returns element's end tag.
 	 * @return string
 	 */
-	public function endTag()
+	public function endTag(): string
 	{
 		return $this->name && !$this->isEmpty ? '</' . $this->name . '>' : '';
 	}
@@ -510,7 +512,7 @@ public function endTag()
 	 * @return string
 	 * @internal
 	 */
-	public function attributes()
+	public function attributes(): string
 	{
 		if (!is_array($this->attrs)) {
 			return '';
diff --git a/src/Utils/IHtmlString.php b/src/Utils/IHtmlString.php
index 71e44ca94..5fb24f408 100644
--- a/src/Utils/IHtmlString.php
+++ b/src/Utils/IHtmlString.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 
@@ -14,6 +16,6 @@ interface IHtmlString
 	/**
 	 * @return string in HTML format
 	 */
-	function __toString();
+	function __toString(): string;
 
 }
diff --git a/src/Utils/ITranslator.php b/src/Utils/ITranslator.php
index 6c62415e6..43b9d21b7 100644
--- a/src/Utils/ITranslator.php
+++ b/src/Utils/ITranslator.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Localization;
 
 
@@ -20,6 +22,6 @@ interface ITranslator
 	 * @param  int      plural count
 	 * @return string
 	 */
-	function translate($message, $count = NULL);
+	function translate(string $message, int $count = NULL): string;
 
 }
diff --git a/src/Utils/Image.php b/src/Utils/Image.php
index 7148b02b8..83738bfab 100644
--- a/src/Utils/Image.php
+++ b/src/Utils/Image.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -124,7 +126,7 @@ class Image extends Nette\Object
 	 * @param  int  transparency 0..127
 	 * @return array
 	 */
-	public static function rgb($red, $green, $blue, $transparency = 0)
+	public static function rgb(int $red, int $green, int $blue, int $transparency = 0): array
 	{
 		return [
 			'red' => max(0, min(255, (int) $red)),
@@ -143,7 +145,7 @@ public static function rgb($red, $green, $blue, $transparency = 0)
 	 * @throws UnknownImageFileException if file not found or file type is not known
 	 * @return self
 	 */
-	public static function fromFile($file, & $format = NULL)
+	public static function fromFile(string $file, & $format = NULL): self
 	{
 		if (!extension_loaded('gd')) {
 			throw new Nette\NotSupportedException('PHP extension GD is not loaded.');
@@ -159,7 +161,7 @@ public static function fromFile($file, & $format = NULL)
 		if (!isset($funcs[$format])) {
 			throw new UnknownImageFileException(is_file($file) ? "Unknown type of file '$file'." : "File '$file' not found.");
 		}
-		return new static(Callback::invokeSafe($funcs[$format], [$file], function ($message) {
+		return new static(Callback::invokeSafe($funcs[$format], [$file], function (string $message) {
 			throw new ImageException($message);
 		}));
 	}
@@ -172,7 +174,7 @@ public static function fromFile($file, & $format = NULL)
 	 * @return self
 	 * @throws ImageException
 	 */
-	public static function fromString($s, & $format = NULL)
+	public static function fromString(string $s, & $format = NULL): self
 	{
 		if (!extension_loaded('gd')) {
 			throw new Nette\NotSupportedException('PHP extension GD is not loaded.');
@@ -183,7 +185,7 @@ public static function fromString($s, & $format = NULL)
 			$format = in_array($tmp, [self::JPEG, self::PNG, self::GIF], TRUE) ? $tmp : NULL;
 		}
 
-		return new static(Callback::invokeSafe('imagecreatefromstring', [$s], function ($message) {
+		return new static(Callback::invokeSafe('imagecreatefromstring', [$s], function (string $message) {
 			throw new ImageException($message);
 		}));
 	}
@@ -196,7 +198,7 @@ public static function fromString($s, & $format = NULL)
 	 * @param  array
 	 * @return self
 	 */
-	public static function fromBlank($width, $height, $color = NULL)
+	public static function fromBlank(int $width, int $height, array $color = NULL): self
 	{
 		if (!extension_loaded('gd')) {
 			throw new Nette\NotSupportedException('PHP extension GD is not loaded.');
@@ -235,7 +237,7 @@ public function __construct($image)
 	 * Returns image width.
 	 * @return int
 	 */
-	public function getWidth()
+	public function getWidth(): int
 	{
 		return imagesx($this->image);
 	}
@@ -245,7 +247,7 @@ public function getWidth()
 	 * Returns image height.
 	 * @return int
 	 */
-	public function getHeight()
+	public function getHeight(): int
 	{
 		return imagesy($this->image);
 	}
@@ -256,7 +258,7 @@ public function getHeight()
 	 * @param  resource
 	 * @return self
 	 */
-	protected function setImageResource($image)
+	protected function setImageResource($image): self
 	{
 		if (!is_resource($image) || get_resource_type($image) !== 'gd') {
 			throw new Nette\InvalidArgumentException('Image is not valid.');
@@ -283,7 +285,7 @@ public function getImageResource()
 	 * @param  int    flags
 	 * @return self
 	 */
-	public function resize($width, $height, $flags = self::FIT)
+	public function resize($width, $height, int $flags = self::FIT): self
 	{
 		if ($flags & self::EXACT) {
 			return $this->resize($width, $height, self::FILL)->crop('50%', '50%', $width, $height);
@@ -317,7 +319,7 @@ public function resize($width, $height, $flags = self::FIT)
 	 * @param  int    flags
 	 * @return array
 	 */
-	public static function calculateSize($srcWidth, $srcHeight, $newWidth, $newHeight, $flags = self::FIT)
+	public static function calculateSize($srcWidth, $srcHeight, $newWidth, $newHeight, int $flags = self::FIT): array
 	{
 		if (is_string($newWidth) && substr($newWidth, -1) === '%') {
 			$newWidth = (int) round($srcWidth / 100 * abs($newWidth));
@@ -382,7 +384,7 @@ public static function calculateSize($srcWidth, $srcHeight, $newWidth, $newHeigh
 	 * @param  mixed  height in pixels or percent
 	 * @return self
 	 */
-	public function crop($left, $top, $width, $height)
+	public function crop($left, $top, $width, $height): self
 	{
 		list($r['x'], $r['y'], $r['width'], $r['height'])
 			= static::calculateCutout($this->getWidth(), $this->getHeight(), $left, $top, $width, $height);
@@ -407,7 +409,7 @@ public function crop($left, $top, $width, $height)
 	 * @param  mixed  height in pixels or percent
 	 * @return array
 	 */
-	public static function calculateCutout($srcWidth, $srcHeight, $left, $top, $newWidth, $newHeight)
+	public static function calculateCutout($srcWidth, $srcHeight, $left, $top, $newWidth, $newHeight): array
 	{
 		if (is_string($newWidth) && substr($newWidth, -1) === '%') {
 			$newWidth = (int) round($srcWidth / 100 * $newWidth);
@@ -439,7 +441,7 @@ public static function calculateCutout($srcWidth, $srcHeight, $left, $top, $newW
 	 * Sharpen image.
 	 * @return self
 	 */
-	public function sharpen()
+	public function sharpen(): self
 	{
 		imageconvolution($this->image, [ // my magic numbers ;)
 			[-1, -1, -1],
@@ -458,7 +460,7 @@ public function sharpen()
 	 * @param  int  opacity 0..100
 	 * @return self
 	 */
-	public function place(Image $image, $left = 0, $top = 0, $opacity = 100)
+	public function place(Image $image, $left = 0, $top = 0, int $opacity = 100): self
 	{
 		$opacity = max(0, min(100, (int) $opacity));
 
@@ -504,7 +506,7 @@ public function place(Image $image, $left = 0, $top = 0, $opacity = 100)
 	 * @param  int  optional image type
 	 * @return bool TRUE on success or FALSE on failure.
 	 */
-	public function save($file = NULL, $quality = NULL, $type = NULL)
+	public function save(string $file = NULL, int $quality = NULL, int $type = NULL): bool
 	{
 		if ($type === NULL) {
 			switch (strtolower($ext = pathinfo($file, PATHINFO_EXTENSION))) {
@@ -547,7 +549,7 @@ public function save($file = NULL, $quality = NULL, $type = NULL)
 	 * @param  int  quality 0..100 (for JPEG and PNG)
 	 * @return string
 	 */
-	public function toString($type = self::JPEG, $quality = NULL)
+	public function toString(int $type = self::JPEG, int $quality = NULL): string
 	{
 		ob_start();
 		$this->save(NULL, $quality, $type);
@@ -559,7 +561,7 @@ public function toString($type = self::JPEG, $quality = NULL)
 	 * Outputs image to string.
 	 * @return string
 	 */
-	public function __toString()
+	public function __toString(): string
 	{
 		try {
 			return $this->toString();
@@ -578,7 +580,7 @@ public function __toString()
 	 * @param  int  quality 0..100 (for JPEG and PNG)
 	 * @return bool TRUE on success or FALSE on failure.
 	 */
-	public function send($type = self::JPEG, $quality = NULL)
+	public function send(int $type = self::JPEG, int $quality = NULL): bool
 	{
 		if (!in_array($type, [self::JPEG, self::PNG, self::GIF], TRUE)) {
 			throw new Nette\InvalidArgumentException("Unsupported image type '$type'.");
@@ -596,7 +598,7 @@ public function send($type = self::JPEG, $quality = NULL)
 	 * @return mixed
 	 * @throws Nette\MemberAccessException
 	 */
-	public function __call($name, $args)
+	public function __call(string $name, array $args)
 	{
 		$function = 'image' . $name;
 		if (!function_exists($function)) {
diff --git a/src/Utils/Json.php b/src/Utils/Json.php
index 8bdbf6e86..d3c08f9bf 100644
--- a/src/Utils/Json.php
+++ b/src/Utils/Json.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -34,7 +36,7 @@ final public function __construct()
 	 * @param  int  accepts Json::PRETTY
 	 * @return string
 	 */
-	public static function encode($value, $options = 0)
+	public static function encode($value, int $options = 0): string
 	{
 		$flags = JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | ($options & self::PRETTY ? JSON_PRETTY_PRINT : 0);
 
@@ -54,7 +56,7 @@ public static function encode($value, $options = 0)
 	 * @param  int  accepts Json::FORCE_ARRAY
 	 * @return mixed
 	 */
-	public static function decode($json, $options = 0)
+	public static function decode(string $json, int $options = 0)
 	{
 		$json = (string) $json;
 		if (defined('JSON_C_VERSION') && !preg_match('##u', $json)) {
diff --git a/src/Utils/Object.php b/src/Utils/Object.php
index fee765cf6..763e01080 100644
--- a/src/Utils/Object.php
+++ b/src/Utils/Object.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette;
 
 use Nette;
@@ -70,7 +72,7 @@ public static function getReflection()
 	 * @return mixed
 	 * @throws MemberAccessException
 	 */
-	public function __call($name, $args)
+	public function __call(string $name, array $args)
 	{
 		return ObjectMixin::call($this, $name, $args);
 	}
@@ -95,7 +97,7 @@ public static function __callStatic($name, $args)
 	 * @param  callable
 	 * @return mixed
 	 */
-	public static function extensionMethod($name, $callback = NULL)
+	public static function extensionMethod(string $name, callable $callback = NULL)
 	{
 		if (strpos($name, '::') === FALSE) {
 			$class = get_called_class();
@@ -117,7 +119,7 @@ public static function extensionMethod($name, $callback = NULL)
 	 * @return mixed   property value
 	 * @throws MemberAccessException if the property is not defined.
 	 */
-	public function &__get($name)
+	public function &__get(string $name)
 	{
 		return ObjectMixin::get($this, $name);
 	}
@@ -130,7 +132,7 @@ public function &__get($name)
 	 * @return void
 	 * @throws MemberAccessException if the property is not defined or is read-only
 	 */
-	public function __set($name, $value)
+	public function __set(string $name, $value)
 	{
 		ObjectMixin::set($this, $name, $value);
 	}
@@ -141,7 +143,7 @@ public function __set($name, $value)
 	 * @param  string  property name
 	 * @return bool
 	 */
-	public function __isset($name)
+	public function __isset(string $name): bool
 	{
 		return ObjectMixin::has($this, $name);
 	}
@@ -153,7 +155,7 @@ public function __isset($name)
 	 * @return void
 	 * @throws MemberAccessException
 	 */
-	public function __unset($name)
+	public function __unset(string $name)
 	{
 		ObjectMixin::remove($this, $name);
 	}
diff --git a/src/Utils/ObjectMixin.php b/src/Utils/ObjectMixin.php
index cac75b5a6..a4754255e 100644
--- a/src/Utils/ObjectMixin.php
+++ b/src/Utils/ObjectMixin.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -43,7 +45,7 @@ final public function __construct()
 	 * @return mixed
 	 * @throws MemberAccessException
 	 */
-	public static function call($_this, $name, $args)
+	public static function call($_this, string $name, array $args)
 	{
 		$class = get_class($_this);
 		$isProp = self::hasProperty($class, $name);
@@ -110,7 +112,7 @@ public static function call($_this, $name, $args)
 	 * @return void
 	 * @throws MemberAccessException
 	 */
-	public static function callStatic($class, $method, $args)
+	public static function callStatic(string $class, string $method, array $args)
 	{
 		$hint = self::getSuggestion(array_filter(
 			get_class_methods($class),
@@ -127,7 +129,7 @@ function ($m) use ($class) { return (new \ReflectionMethod($class, $m))->isStati
 	 * @return mixed   property value
 	 * @throws MemberAccessException if the property is not defined.
 	 */
-	public static function & get($_this, $name)
+	public static function & get($_this, string $name)
 	{
 		$class = get_class($_this);
 		$uname = ucfirst($name);
@@ -182,7 +184,7 @@ public static function & get($_this, $name)
 	 * @return void
 	 * @throws MemberAccessException if the property is not defined or is read-only
 	 */
-	public static function set($_this, $name, $value)
+	public static function set($_this, string $name, $value)
 	{
 		$class = get_class($_this);
 		$uname = ucfirst($name);
@@ -217,7 +219,7 @@ public static function set($_this, $name, $value)
 	 * @return void
 	 * @throws MemberAccessException
 	 */
-	public static function remove($_this, $name)
+	public static function remove($_this, string $name)
 	{
 		$class = get_class($_this);
 		if (!self::hasProperty($class, $name)) { // strict class
@@ -232,7 +234,7 @@ public static function remove($_this, $name)
 	 * @param  string  property name
 	 * @return bool
 	 */
-	public static function has($_this, $name)
+	public static function has($_this, string $name): bool
 	{
 		$name = ucfirst($name);
 		$methods = & self::getMethods(get_class($_this));
@@ -244,7 +246,7 @@ public static function has($_this, $name)
 	 * Checks if the public non-static property exists.
 	 * @return mixed
 	 */
-	private static function hasProperty($class, $name)
+	private static function hasProperty(string $class, string $name)
 	{
 		$prop = & self::$props[$class][$name];
 		if ($prop === NULL) {
@@ -265,7 +267,7 @@ private static function hasProperty($class, $name)
 	 * Returns array of public (static, non-static and magic) methods.
 	 * @return array
 	 */
-	private static function & getMethods($class)
+	private static function & getMethods(string $class)
 	{
 		if (!isset(self::$methods[$class])) {
 			self::$methods[$class] = array_fill_keys(get_class_methods($class), 0) + self::getMagicMethods($class);
@@ -281,7 +283,7 @@ private static function & getMethods($class)
 	 * Returns array of magic methods defined by annotation @method.
 	 * @return array
 	 */
-	public static function getMagicMethods($class)
+	public static function getMagicMethods(string $class): array
 	{
 		$rc = new \ReflectionClass($class);
 		preg_match_all('~^
@@ -321,7 +323,7 @@ public static function getMagicMethods($class)
 	 * @return bool
 	 * @internal
 	 */
-	public static function checkType(& $val, $type)
+	public static function checkType(& $val, string $type): bool
 	{
 		if (strpos($type, '|') !== FALSE) {
 			$found = NULL;
@@ -390,7 +392,7 @@ public static function checkType(& $val, $type)
 	 * @param  mixed   callable
 	 * @return void
 	 */
-	public static function setExtensionMethod($class, $name, $callback)
+	public static function setExtensionMethod(string $class, string $name, callable $callback)
 	{
 		$name = strtolower($name);
 		self::$extMethods[$name][$class] = Callback::check($callback);
@@ -404,7 +406,7 @@ public static function setExtensionMethod($class, $name, $callback)
 	 * @param  string
 	 * @return mixed
 	 */
-	public static function getExtensionMethod($class, $name)
+	public static function getExtensionMethod(string $class, string $name)
 	{
 		$list = & self::$extMethods[strtolower($name)];
 		$cache = & $list[''][$class];
diff --git a/src/Utils/Paginator.php b/src/Utils/Paginator.php
index c2ce308fb..60e87424c 100644
--- a/src/Utils/Paginator.php
+++ b/src/Utils/Paginator.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -46,9 +48,9 @@ class Paginator extends Nette\Object
 	 * @param  int
 	 * @return self
 	 */
-	public function setPage($page)
+	public function setPage(int $page): self
 	{
-		$this->page = (int) $page;
+		$this->page = $page;
 		return $this;
 	}
 
@@ -57,7 +59,7 @@ public function setPage($page)
 	 * Returns current page number.
 	 * @return int
 	 */
-	public function getPage()
+	public function getPage(): int
 	{
 		return $this->base + $this->getPageIndex();
 	}
@@ -67,7 +69,7 @@ public function getPage()
 	 * Returns first page number.
 	 * @return int
 	 */
-	public function getFirstPage()
+	public function getFirstPage(): int
 	{
 		return $this->base;
 	}
@@ -88,9 +90,9 @@ public function getLastPage()
 	 * @param  int
 	 * @return self
 	 */
-	public function setBase($base)
+	public function setBase(int $base): self
 	{
-		$this->base = (int) $base;
+		$this->base = $base;
 		return $this;
 	}
 
@@ -99,7 +101,7 @@ public function setBase($base)
 	 * Returns first page (base) number.
 	 * @return int
 	 */
-	public function getBase()
+	public function getBase(): int
 	{
 		return $this->base;
 	}
@@ -109,7 +111,7 @@ public function getBase()
 	 * Returns zero-based page number.
 	 * @return int
 	 */
-	protected function getPageIndex()
+	protected function getPageIndex(): int
 	{
 		$index = max(0, $this->page - $this->base);
 		return $this->itemCount === NULL ? $index : min($index, max(0, $this->getPageCount() - 1));
@@ -120,7 +122,7 @@ protected function getPageIndex()
 	 * Is the current page the first one?
 	 * @return bool
 	 */
-	public function isFirst()
+	public function isFirst(): bool
 	{
 		return $this->getPageIndex() === 0;
 	}
@@ -130,7 +132,7 @@ public function isFirst()
 	 * Is the current page the last one?
 	 * @return bool
 	 */
-	public function isLast()
+	public function isLast(): bool
 	{
 		return $this->itemCount === NULL ? FALSE : $this->getPageIndex() >= $this->getPageCount() - 1;
 	}
@@ -151,9 +153,9 @@ public function getPageCount()
 	 * @param  int
 	 * @return self
 	 */
-	public function setItemsPerPage($itemsPerPage)
+	public function setItemsPerPage(int $itemsPerPage): self
 	{
-		$this->itemsPerPage = max(1, (int) $itemsPerPage);
+		$this->itemsPerPage = max(1, $itemsPerPage);
 		return $this;
 	}
 
@@ -162,7 +164,7 @@ public function setItemsPerPage($itemsPerPage)
 	 * Returns the number of items to display on a single page.
 	 * @return int
 	 */
-	public function getItemsPerPage()
+	public function getItemsPerPage(): int
 	{
 		return $this->itemsPerPage;
 	}
@@ -173,9 +175,9 @@ public function getItemsPerPage()
 	 * @param  int (or NULL as infinity)
 	 * @return self
 	 */
-	public function setItemCount($itemCount)
+	public function setItemCount(int $itemCount = NULL): self
 	{
-		$this->itemCount = ($itemCount === FALSE || $itemCount === NULL) ? NULL : max(0, (int) $itemCount);
+		$this->itemCount = $itemCount === NULL ? NULL : max(0, $itemCount);
 		return $this;
 	}
 
@@ -194,7 +196,7 @@ public function getItemCount()
 	 * Returns the absolute index of the first item on current page.
 	 * @return int
 	 */
-	public function getOffset()
+	public function getOffset(): int
 	{
 		return $this->getPageIndex() * $this->itemsPerPage;
 	}
diff --git a/src/Utils/Random.php b/src/Utils/Random.php
index 5b93083b9..3d7fe649e 100644
--- a/src/Utils/Random.php
+++ b/src/Utils/Random.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -22,7 +24,7 @@ class Random
 	 * @param  string
 	 * @return string
 	 */
-	public static function generate($length = 10, $charlist = '0-9a-z')
+	public static function generate(int $length = 10, string $charlist = '0-9a-z'): string
 	{
 		$charlist = count_chars(preg_replace_callback('#.-.#', function (array $m) {
 			return implode('', range($m[0][0], $m[0][2]));
diff --git a/src/Utils/Strings.php b/src/Utils/Strings.php
index 66ccc6ebc..b960a5a84 100644
--- a/src/Utils/Strings.php
+++ b/src/Utils/Strings.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -33,7 +35,7 @@ final public function __construct()
 	 * @param  string  byte stream to check
 	 * @return bool
 	 */
-	public static function checkEncoding($s)
+	public static function checkEncoding(string $s): bool
 	{
 		return $s === self::fixEncoding($s);
 	}
@@ -44,7 +46,7 @@ public static function checkEncoding($s)
 	 * @param  string  byte stream to fix
 	 * @return string
 	 */
-	public static function fixEncoding($s)
+	public static function fixEncoding(string $s): string
 	{
 		// removes xD800-xDFFF, x110000 and higher
 		return htmlspecialchars_decode(htmlspecialchars($s, ENT_NOQUOTES | ENT_IGNORE, 'UTF-8'), ENT_NOQUOTES);
@@ -57,7 +59,7 @@ public static function fixEncoding($s)
 	 * @return string
 	 * @throws Nette\InvalidArgumentException if code point is not in valid range
 	 */
-	public static function chr($code)
+	public static function chr(int $code): string
 	{
 		if ($code < 0 || ($code >= 0xD800 && $code <= 0xDFFF) || $code > 0x10FFFF) {
 			throw new Nette\InvalidArgumentException('Code point must be in range 0x0 to 0xD7FF or 0xE000 to 0x10FFFF.');
@@ -72,7 +74,7 @@ public static function chr($code)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function startsWith($haystack, $needle)
+	public static function startsWith(string $haystack, string $needle): bool
 	{
 		return strncmp($haystack, $needle, strlen($needle)) === 0;
 	}
@@ -84,7 +86,7 @@ public static function startsWith($haystack, $needle)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function endsWith($haystack, $needle)
+	public static function endsWith(string $haystack, string $needle): bool
 	{
 		return strlen($needle) === 0 || substr($haystack, -strlen($needle)) === $needle;
 	}
@@ -96,7 +98,7 @@ public static function endsWith($haystack, $needle)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function contains($haystack, $needle)
+	public static function contains(string $haystack, string $needle): bool
 	{
 		return strpos($haystack, $needle) !== FALSE;
 	}
@@ -109,7 +111,7 @@ public static function contains($haystack, $needle)
 	 * @param  int in characters (code points)
 	 * @return string
 	 */
-	public static function substring($s, $start, $length = NULL)
+	public static function substring(string $s, int $start, int $length = NULL): string
 	{
 		if (function_exists('mb_substr')) {
 			return mb_substr($s, $start, $length, 'UTF-8'); // MB is much faster
@@ -127,7 +129,7 @@ public static function substring($s, $start, $length = NULL)
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function normalize($s)
+	public static function normalize(string $s): string
 	{
 		$s = self::normalizeNewLines($s);
 
@@ -149,7 +151,7 @@ public static function normalize($s)
 	 * @param  string  UTF-8 encoding or 8-bit
 	 * @return string
 	 */
-	public static function normalizeNewLines($s)
+	public static function normalizeNewLines(string $s): string
 	{
 		return str_replace(["\r\n", "\r"], "\n", $s);
 	}
@@ -160,7 +162,7 @@ public static function normalizeNewLines($s)
 	 * @param  string  UTF-8 encoding
 	 * @return string  ASCII
 	 */
-	public static function toAscii($s)
+	public static function toAscii(string $s): string
 	{
 		$s = preg_replace('#[^\x09\x0A\x0D\x20-\x7E\xA0-\x{2FF}\x{370}-\x{10FFFF}]#u', '', $s);
 		$s = strtr($s, '`\'"^~?', "\x01\x02\x03\x04\x05\x06");
@@ -199,7 +201,7 @@ public static function toAscii($s)
 	 * @param  bool
 	 * @return string
 	 */
-	public static function webalize($s, $charlist = NULL, $lower = TRUE)
+	public static function webalize(string $s, string $charlist = NULL, bool $lower = TRUE): string
 	{
 		$s = self::toAscii($s);
 		if ($lower) {
@@ -218,7 +220,7 @@ public static function webalize($s, $charlist = NULL, $lower = TRUE)
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function truncate($s, $maxLen, $append = "\xE2\x80\xA6")
+	public static function truncate(string $s, int $maxLen, string $append = "\xE2\x80\xA6"): string
 	{
 		if (self::length($s) > $maxLen) {
 			$maxLen = $maxLen - self::length($append);
@@ -243,7 +245,7 @@ public static function truncate($s, $maxLen, $append = "\xE2\x80\xA6")
 	 * @param  string
 	 * @return string
 	 */
-	public static function indent($s, $level = 1, $chars = "\t")
+	public static function indent(string $s, int $level = 1, string $chars = "\t"): string
 	{
 		if ($level > 0) {
 			$s = self::replace($s, '#(?:^|[\r\n]+)(?=[^\r\n])#', '$0' . str_repeat($chars, $level));
@@ -257,7 +259,7 @@ public static function indent($s, $level = 1, $chars = "\t")
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function lower($s)
+	public static function lower(string $s): string
 	{
 		return mb_strtolower($s, 'UTF-8');
 	}
@@ -268,7 +270,7 @@ public static function lower($s)
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function firstLower($s)
+	public static function firstLower(string $s): string
 	{
 		return self::lower(self::substring($s, 0, 1)) . self::substring($s, 1);
 	}
@@ -279,7 +281,7 @@ public static function firstLower($s)
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function upper($s)
+	public static function upper(string $s): string
 	{
 		return mb_strtoupper($s, 'UTF-8');
 	}
@@ -290,7 +292,7 @@ public static function upper($s)
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function firstUpper($s)
+	public static function firstUpper(string $s): string
 	{
 		return self::upper(self::substring($s, 0, 1)) . self::substring($s, 1);
 	}
@@ -301,7 +303,7 @@ public static function firstUpper($s)
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function capitalize($s)
+	public static function capitalize(string $s): string
 	{
 		return mb_convert_case($s, MB_CASE_TITLE, 'UTF-8');
 	}
@@ -314,7 +316,7 @@ public static function capitalize($s)
 	 * @param  int
 	 * @return bool
 	 */
-	public static function compare($left, $right, $len = NULL)
+	public static function compare(string $left, string $right, int $len = NULL): bool
 	{
 		if ($len < 0) {
 			$left = self::substring($left, $len, -$len);
@@ -332,7 +334,7 @@ public static function compare($left, $right, $len = NULL)
 	 * @param  string|array
 	 * @return string
 	 */
-	public static function findPrefix(...$strings)
+	public static function findPrefix(...$strings): string
 	{
 		if (is_array($strings[0])) {
 			$strings = $strings[0];
@@ -358,7 +360,7 @@ public static function findPrefix(...$strings)
 	 * @param  string
 	 * @return int
 	 */
-	public static function length($s)
+	public static function length(string $s): int
 	{
 		return function_exists('mb_strlen') ? mb_strlen($s, 'UTF-8') : strlen(utf8_decode($s));
 	}
@@ -370,7 +372,7 @@ public static function length($s)
 	 * @param  string
 	 * @return string
 	 */
-	public static function trim($s, $charlist = self::TRIM_CHARACTERS)
+	public static function trim(string $s, string $charlist = self::TRIM_CHARACTERS): string
 	{
 		$charlist = preg_quote($charlist, '#');
 		return self::replace($s, '#^['.$charlist.']+|['.$charlist.']+\z#u', '');
@@ -384,7 +386,7 @@ public static function trim($s, $charlist = self::TRIM_CHARACTERS)
 	 * @param  string
 	 * @return string
 	 */
-	public static function padLeft($s, $length, $pad = ' ')
+	public static function padLeft(string $s, int $length, string $pad = ' '): string
 	{
 		$length = max(0, $length - self::length($s));
 		$padLen = self::length($pad);
@@ -399,7 +401,7 @@ public static function padLeft($s, $length, $pad = ' ')
 	 * @param  string
 	 * @return string
 	 */
-	public static function padRight($s, $length, $pad = ' ')
+	public static function padRight(string $s, int $length, string $pad = ' '): string
 	{
 		$length = max(0, $length - self::length($s));
 		$padLen = self::length($pad);
@@ -412,7 +414,7 @@ public static function padRight($s, $length, $pad = ' ')
 	 * @param  string  UTF-8 encoding
 	 * @return string
 	 */
-	public static function reverse($s)
+	public static function reverse(string $s): string
 	{
 		return iconv('UTF-32LE', 'UTF-8', strrev(iconv('UTF-8', 'UTF-32BE', $s)));
 	}
@@ -422,7 +424,7 @@ public static function reverse($s)
 	 * Use Nette\Utils\Random::generate
 	 * @deprecated
 	 */
-	public static function random($length = 10, $charlist = '0-9a-z')
+	public static function random(int $length = 10, string $charlist = '0-9a-z'): string
 	{
 		return Random::generate($length, $charlist);
 	}
@@ -435,7 +437,7 @@ public static function random($length = 10, $charlist = '0-9a-z')
 	 * @param  int  negative value means searching from the end
 	 * @return string|FALSE  returns FALSE if the needle was not found
 	 */
-	public static function before($haystack, $needle, $nth = 1)
+	public static function before(string $haystack, string $needle, int $nth = 1)
 	{
 		$pos = self::pos($haystack, $needle, $nth);
 		return $pos === FALSE
@@ -451,7 +453,7 @@ public static function before($haystack, $needle, $nth = 1)
 	 * @param  int  negative value means searching from the end
 	 * @return string|FALSE  returns FALSE if the needle was not found
 	 */
-	public static function after($haystack, $needle, $nth = 1)
+	public static function after(string $haystack, string $needle, int $nth = 1)
 	{
 		$pos = self::pos($haystack, $needle, $nth);
 		return $pos === FALSE
@@ -467,7 +469,7 @@ public static function after($haystack, $needle, $nth = 1)
 	 * @param  int  negative value means searching from the end
 	 * @return int|FALSE  offset in characters or FALSE if the needle was not found
 	 */
-	public static function indexOf($haystack, $needle, $nth = 1)
+	public static function indexOf(string $haystack, string $needle, int $nth = 1)
 	{
 		$pos = self::pos($haystack, $needle, $nth);
 		return $pos === FALSE
@@ -480,7 +482,7 @@ public static function indexOf($haystack, $needle, $nth = 1)
 	 * Returns position of $nth occurence of $needle in $haystack.
 	 * @return int|FALSE  offset in bytes or FALSE if the needle was not found
 	 */
-	private static function pos($haystack, $needle, $nth = 1)
+	private static function pos(string $haystack, string $needle, int $nth = 1)
 	{
 		if (!$nth) {
 			return FALSE;
@@ -513,7 +515,7 @@ private static function pos($haystack, $needle, $nth = 1)
 	 * @param  int
 	 * @return array
 	 */
-	public static function split($subject, $pattern, $flags = 0)
+	public static function split(string $subject, string $pattern, int $flags = 0): array
 	{
 		return self::pcre('preg_split', [$pattern, $subject, -1, $flags | PREG_SPLIT_DELIM_CAPTURE]);
 	}
@@ -527,7 +529,7 @@ public static function split($subject, $pattern, $flags = 0)
 	 * @param  int  offset in bytes
 	 * @return mixed
 	 */
-	public static function match($subject, $pattern, $flags = 0, $offset = 0)
+	public static function match(string $subject, string $pattern, int $flags = 0, int $offset = 0)
 	{
 		if ($offset > strlen($subject)) {
 			return NULL;
@@ -546,7 +548,7 @@ public static function match($subject, $pattern, $flags = 0, $offset = 0)
 	 * @param  int  offset in bytes
 	 * @return array
 	 */
-	public static function matchAll($subject, $pattern, $flags = 0, $offset = 0)
+	public static function matchAll(string $subject, string $pattern, int $flags = 0, int $offset = 0): array
 	{
 		if ($offset > strlen($subject)) {
 			return [];
@@ -568,7 +570,7 @@ public static function matchAll($subject, $pattern, $flags = 0, $offset = 0)
 	 * @param  int
 	 * @return string
 	 */
-	public static function replace($subject, $pattern, $replacement = NULL, $limit = -1)
+	public static function replace(string $subject, $pattern, $replacement = NULL, int $limit = -1): string
 	{
 		if (is_object($replacement) || is_array($replacement)) {
 			if ($replacement instanceof Nette\Callback) {
@@ -591,7 +593,7 @@ public static function replace($subject, $pattern, $replacement = NULL, $limit =
 
 
 	/** @internal */
-	public static function pcre($func, $args)
+	public static function pcre(string $func, $args)
 	{
 		static $messages = [
 			PREG_INTERNAL_ERROR => 'Internal error',
@@ -601,7 +603,7 @@ public static function pcre($func, $args)
 			PREG_BAD_UTF8_OFFSET_ERROR => 'Offset didn\'t correspond to the begin of a valid UTF-8 code point',
 			6 => 'Failed due to limited JIT stack space', // PREG_JIT_STACKLIMIT_ERROR
 		];
-		$res = Callback::invokeSafe($func, $args, function ($message) use ($args) {
+		$res = Callback::invokeSafe($func, $args, function (string $message) use ($args) {
 			// compile-time error, not detectable by preg_last_error
 			throw new RegexpException($message . ' in pattern: ' . implode(' or ', (array) $args[0]));
 		});
diff --git a/src/Utils/Validators.php b/src/Utils/Validators.php
index 21a5b649e..1be010cf8 100644
--- a/src/Utils/Validators.php
+++ b/src/Utils/Validators.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette\Utils;
 
 use Nette;
@@ -71,7 +73,7 @@ class Validators extends Nette\Object
 	 * @param  string  label
 	 * @return void
 	 */
-	public static function assert($value, $expected, $label = 'variable')
+	public static function assert($value, string $expected, string $label = 'variable')
 	{
 		if (!static::is($value, $expected)) {
 			$expected = str_replace(['|', ':'], [' or ', ' in range '], $expected);
@@ -97,7 +99,7 @@ public static function assert($value, $expected, $label = 'variable')
 	 * @param  string
 	 * @return void
 	 */
-	public static function assertField($arr, $field, $expected = NULL, $label = "item '%' in array")
+	public static function assertField($arr, string $field, string $expected = NULL, string $label = "item '%' in array")
 	{
 		self::assert($arr, 'array', 'first argument');
 		if (!array_key_exists($field, $arr)) {
@@ -115,7 +117,7 @@ public static function assertField($arr, $field, $expected = NULL, $label = "ite
 	 * @param  string  expected types separated by pipe with optional ranges
 	 * @return bool
 	 */
-	public static function is($value, $expected)
+	public static function is($value, string $expected): bool
 	{
 		foreach (explode('|', $expected) as $item) {
 			list($type) = $item = explode(':', $item, 2);
@@ -158,7 +160,7 @@ public static function is($value, $expected)
 	 * Finds whether a value is an integer.
 	 * @return bool
 	 */
-	public static function isNumericInt($value)
+	public static function isNumericInt($value): bool
 	{
 		return is_int($value) || is_string($value) && preg_match('#^-?[0-9]+\z#', $value);
 	}
@@ -168,7 +170,7 @@ public static function isNumericInt($value)
 	 * Finds whether a string is a floating point number in decimal base.
 	 * @return bool
 	 */
-	public static function isNumeric($value)
+	public static function isNumeric($value): bool
 	{
 		return is_float($value) || is_int($value) || is_string($value) && preg_match('#^-?[0-9]*[.]?[0-9]+\z#', $value);
 	}
@@ -178,7 +180,7 @@ public static function isNumeric($value)
 	 * Finds whether a value is a syntactically correct callback.
 	 * @return bool
 	 */
-	public static function isCallable($value)
+	public static function isCallable($value): bool
 	{
 		return $value && is_callable($value, TRUE);
 	}
@@ -189,7 +191,7 @@ public static function isCallable($value)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function isUnicode($value)
+	public static function isUnicode($value): bool
 	{
 		return is_string($value) && preg_match('##u', $value);
 	}
@@ -199,7 +201,7 @@ public static function isUnicode($value)
 	 * Finds whether a value is "falsy".
 	 * @return bool
 	 */
-	public static function isNone($value)
+	public static function isNone($value): bool
 	{
 		return $value == NULL; // intentionally ==
 	}
@@ -210,7 +212,7 @@ public static function isNone($value)
 	 * @param  array
 	 * @return bool
 	 */
-	public static function isList($value)
+	public static function isList($value): bool
 	{
 		return Arrays::isList($value);
 	}
@@ -222,7 +224,7 @@ public static function isList($value)
 	 * @param  array  min and max value pair
 	 * @return bool
 	 */
-	public static function isInRange($value, $range)
+	public static function isInRange($value, array $range): bool
 	{
 		return (!isset($range[0]) || $range[0] === '' || $value >= $range[0])
 			&& (!isset($range[1]) || $range[1] === '' || $value <= $range[1]);
@@ -234,7 +236,7 @@ public static function isInRange($value, $range)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function isEmail($value)
+	public static function isEmail(string $value): bool
 	{
 		$atom = "[-a-z0-9!#$%&'*+/=?^_`{|}~]"; // RFC 5322 unquoted characters in local-part
 		$alpha = "a-z\x80-\xFF"; // superset of IDN
@@ -252,7 +254,7 @@ public static function isEmail($value)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function isUrl($value)
+	public static function isUrl(string $value): bool
 	{
 		$alpha = "a-z\x80-\xFF";
 		return (bool) preg_match("(^
@@ -273,7 +275,7 @@ public static function isUrl($value)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function isUri($value)
+	public static function isUri(string $value): bool
 	{
 		return (bool) preg_match('#^[a-z\d+\.-]+:\S+\z#i', $value);
 	}
@@ -284,9 +286,9 @@ public static function isUri($value)
 	 * @param  string
 	 * @return bool
 	 */
-	public static function isType($type)
+	public static function isType(string $type): bool
 	{
-		return class_exists($type) || interface_exists($type) || trait_exists($type);
+		return class_exists($type) || interface_exists($type) || (PHP_VERSION_ID >= 50400 && trait_exists($type));
 	}
 
 
@@ -294,7 +296,7 @@ public static function isType($type)
 	 * Checks whether the input is a valid PHP identifier.
 	 * @return bool
 	 */
-	public static function isPhpIdentifier($value)
+	public static function isPhpIdentifier(string $value): bool
 	{
 		return is_string($value) && preg_match('#^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*\z#', $value);
 	}
diff --git a/src/Utils/exceptions.php b/src/Utils/exceptions.php
index 0b759ff06..2b4451b19 100644
--- a/src/Utils/exceptions.php
+++ b/src/Utils/exceptions.php
@@ -5,6 +5,8 @@
  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  */
 
+declare(strict_types = 1);
+
 namespace Nette;
 
 
diff --git a/tests/Iterators/CachingIterator.basic.phpt b/tests/Iterators/CachingIterator.basic.phpt
index 244ff0878..82c7556d7 100644
--- a/tests/Iterators/CachingIterator.basic.phpt
+++ b/tests/Iterators/CachingIterator.basic.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Iterators\CachingIterator basic usage.
  */
 
+declare(strict_types = 1);
+
 use Nette\Iterators;
 use Tester\Assert;
 
diff --git a/tests/Iterators/CachingIterator.construct.phpt b/tests/Iterators/CachingIterator.construct.phpt
index 748f1ef45..19bf1f3fe 100644
--- a/tests/Iterators/CachingIterator.construct.phpt
+++ b/tests/Iterators/CachingIterator.construct.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Iterators\CachingIterator constructor.
  */
 
+declare(strict_types = 1);
+
 use Nette\Iterators;
 use Tester\Assert;
 
diff --git a/tests/Iterators/CachingIterator.width.phpt b/tests/Iterators/CachingIterator.width.phpt
index 09a3d236b..a75227dda 100644
--- a/tests/Iterators/CachingIterator.width.phpt
+++ b/tests/Iterators/CachingIterator.width.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Iterators\CachingIterator width.
  */
 
+declare(strict_types = 1);
+
 use Nette\Iterators;
 use Tester\Assert;
 
diff --git a/tests/Iterators/Mapper.phpt b/tests/Iterators/Mapper.phpt
index 34458572a..2f8cd8b38 100644
--- a/tests/Iterators/Mapper.phpt
+++ b/tests/Iterators/Mapper.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Iterators\Mapper
  */
 
+declare(strict_types = 1);
+
 use Nette\Iterators;
 use Tester\Assert;
 
diff --git a/tests/Utils/ArrayHash.phpt b/tests/Utils/ArrayHash.phpt
index 720a9d2c9..a5c5131f2 100644
--- a/tests/Utils/ArrayHash.phpt
+++ b/tests/Utils/ArrayHash.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\ArrayHash basic usage.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\ArrayHash;
 use Tester\Assert;
 
diff --git a/tests/Utils/ArrayList.phpt b/tests/Utils/ArrayList.phpt
index c85798398..1b60df6de 100644
--- a/tests/Utils/ArrayList.phpt
+++ b/tests/Utils/ArrayList.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\ArrayList basic usage.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\ArrayList;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.associate().error.phpt b/tests/Utils/Arrays.associate().error.phpt
index d9a7cb542..878a9c312 100644
--- a/tests/Utils/Arrays.associate().error.phpt
+++ b/tests/Utils/Arrays.associate().error.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::associate()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.associate().phpt b/tests/Utils/Arrays.associate().phpt
index 8878c29b9..b4c6fbef9 100644
--- a/tests/Utils/Arrays.associate().phpt
+++ b/tests/Utils/Arrays.associate().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::associate()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Nette\Utils\DateTime;
 use Tester\Assert;
diff --git a/tests/Utils/Arrays.flatten().phpt b/tests/Utils/Arrays.flatten().phpt
index e73189dff..c0f9c758e 100644
--- a/tests/Utils/Arrays.flatten().phpt
+++ b/tests/Utils/Arrays.flatten().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::flatten()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.get().phpt b/tests/Utils/Arrays.get().phpt
index 4611caa61..2d5a684f4 100644
--- a/tests/Utils/Arrays.get().phpt
+++ b/tests/Utils/Arrays.get().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::get()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.getRef().phpt b/tests/Utils/Arrays.getRef().phpt
index 285caade9..1266026a4 100644
--- a/tests/Utils/Arrays.getRef().phpt
+++ b/tests/Utils/Arrays.getRef().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::getRef()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.grep().errors.phpt b/tests/Utils/Arrays.grep().errors.phpt
index bd2203875..474797fae 100644
--- a/tests/Utils/Arrays.grep().errors.phpt
+++ b/tests/Utils/Arrays.grep().errors.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::grep() errors.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.grep().phpt b/tests/Utils/Arrays.grep().phpt
index c7576e580..5b2758164 100644
--- a/tests/Utils/Arrays.grep().phpt
+++ b/tests/Utils/Arrays.grep().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::grep()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.insertBefore().phpt b/tests/Utils/Arrays.insertBefore().phpt
index cc38c86a8..cc25a7095 100644
--- a/tests/Utils/Arrays.insertBefore().phpt
+++ b/tests/Utils/Arrays.insertBefore().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::insertBefore() & insertAfter()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.isList.phpt b/tests/Utils/Arrays.isList.phpt
index e048b82be..5c8b0aa03 100644
--- a/tests/Utils/Arrays.isList.phpt
+++ b/tests/Utils/Arrays.isList.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::isList()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.normalize.phpt b/tests/Utils/Arrays.normalize.phpt
index e80fde131..6753017d2 100644
--- a/tests/Utils/Arrays.normalize.phpt
+++ b/tests/Utils/Arrays.normalize.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::searchKey()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.pick().phpt b/tests/Utils/Arrays.pick().phpt
index e266f724a..b5920a548 100644
--- a/tests/Utils/Arrays.pick().phpt
+++ b/tests/Utils/Arrays.pick().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::pick()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.renameKey().phpt b/tests/Utils/Arrays.renameKey().phpt
index 01c479c1e..e3100b39c 100644
--- a/tests/Utils/Arrays.renameKey().phpt
+++ b/tests/Utils/Arrays.renameKey().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::renameKey()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Arrays.searchKey().phpt b/tests/Utils/Arrays.searchKey().phpt
index 13f701afa..29da1631f 100644
--- a/tests/Utils/Arrays.searchKey().phpt
+++ b/tests/Utils/Arrays.searchKey().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Arrays::searchKey()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Arrays;
 use Tester\Assert;
 
diff --git a/tests/Utils/Callback.check.phpt b/tests/Utils/Callback.check.phpt
index 2e0766a1a..9aec79b0e 100644
--- a/tests/Utils/Callback.check.phpt
+++ b/tests/Utils/Callback.check.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Callback::check()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Callback;
 use Tester\Assert;
 
diff --git a/tests/Utils/Callback.closure.phpt b/tests/Utils/Callback.closure.phpt
index f196fe755..5b2182071 100644
--- a/tests/Utils/Callback.closure.phpt
+++ b/tests/Utils/Callback.closure.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Callback closures tests.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Callback;
 use Tester\Assert;
 
diff --git a/tests/Utils/Callback.invoke.phpt b/tests/Utils/Callback.invoke.phpt
index 7294c9e84..0fb805851 100644
--- a/tests/Utils/Callback.invoke.phpt
+++ b/tests/Utils/Callback.invoke.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Callback::invoke() and invokeArgs()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Callback;
 use Tester\Assert;
 
diff --git a/tests/Utils/Callback.invokeSafe.phpt b/tests/Utils/Callback.invokeSafe.phpt
index d3549e8d6..9e5adbd33 100644
--- a/tests/Utils/Callback.invokeSafe.phpt
+++ b/tests/Utils/Callback.invokeSafe.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Callback::invokeSafe()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Callback;
 use Tester\Assert;
 
diff --git a/tests/Utils/DateTime.JSON.phpt b/tests/Utils/DateTime.JSON.phpt
index eb57b297f..02294e4af 100644
--- a/tests/Utils/DateTime.JSON.phpt
+++ b/tests/Utils/DateTime.JSON.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\DateTime & JSON.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 use Nette\Utils\DateTime;
 
diff --git a/tests/Utils/DateTime.createFromFormat.phpt b/tests/Utils/DateTime.createFromFormat.phpt
index efa6574cf..d50401fe8 100644
--- a/tests/Utils/DateTime.createFromFormat.phpt
+++ b/tests/Utils/DateTime.createFromFormat.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\DateTime::createFromFormat().
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 use Nette\Utils\DateTime;
 
diff --git a/tests/Utils/DateTime.from.phpt b/tests/Utils/DateTime.from.phpt
index 4f50cb73b..646c6a34a 100644
--- a/tests/Utils/DateTime.from.phpt
+++ b/tests/Utils/DateTime.from.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\DateTime::from().
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 use Nette\Utils\DateTime;
 
diff --git a/tests/Utils/FileSystem.phpt b/tests/Utils/FileSystem.phpt
index eef6706e0..5d44324d8 100644
--- a/tests/Utils/FileSystem.phpt
+++ b/tests/Utils/FileSystem.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\FileSystem basic usage.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\FileSystem;
 use Tester\Assert;
 
diff --git a/tests/Utils/Html.basic.phpt b/tests/Utils/Html.basic.phpt
index 6c16a9788..ec0de6284 100644
--- a/tests/Utils/Html.basic.phpt
+++ b/tests/Utils/Html.basic.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Html basic usage.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Html;
 use Tester\Assert;
 
diff --git a/tests/Utils/Html.children.phpt b/tests/Utils/Html.children.phpt
index 39571f4dc..4e6a4911f 100644
--- a/tests/Utils/Html.children.phpt
+++ b/tests/Utils/Html.children.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Html children usage.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Html;
 use Tester\Assert;
 
diff --git a/tests/Utils/Html.construct.phpt b/tests/Utils/Html.construct.phpt
index cb93ab3be..c102168ab 100644
--- a/tests/Utils/Html.construct.phpt
+++ b/tests/Utils/Html.construct.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Html::__construct()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Html;
 use Tester\Assert;
 
diff --git a/tests/Utils/Html.data.phpt b/tests/Utils/Html.data.phpt
index 74d5b7d9e..df7926b63 100644
--- a/tests/Utils/Html.data.phpt
+++ b/tests/Utils/Html.data.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Html user data attribute.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Html;
 use Tester\Assert;
 
diff --git a/tests/Utils/Html.style.phpt b/tests/Utils/Html.style.phpt
index 84f7d7aca..29d280e6f 100644
--- a/tests/Utils/Html.style.phpt
+++ b/tests/Utils/Html.style.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Html style & class attribute.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Html;
 use Tester\Assert;
 
diff --git a/tests/Utils/Image.alpha1.phpt b/tests/Utils/Image.alpha1.phpt
index 3ea70e0fa..3e6f3a198 100644
--- a/tests/Utils/Image.alpha1.phpt
+++ b/tests/Utils/Image.alpha1.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Image alpha channel.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Image;
 use Tester\Assert;
 
diff --git a/tests/Utils/Image.clone.phpt b/tests/Utils/Image.clone.phpt
index 84d94cd0f..306b4dbbd 100644
--- a/tests/Utils/Image.clone.phpt
+++ b/tests/Utils/Image.clone.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Image cloning.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Image;
 use Tester\Assert;
 
diff --git a/tests/Utils/Image.drawing.phpt b/tests/Utils/Image.drawing.phpt
index d0b008914..aaa9d021f 100644
--- a/tests/Utils/Image.drawing.phpt
+++ b/tests/Utils/Image.drawing.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Image drawing.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Image;
 use Tester\Assert;
 
diff --git a/tests/Utils/Image.factories.phpt b/tests/Utils/Image.factories.phpt
index 753138079..382850d9b 100644
--- a/tests/Utils/Image.factories.phpt
+++ b/tests/Utils/Image.factories.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Image factories.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Image;
 use Tester\Assert;
 
diff --git a/tests/Utils/Image.resize.phpt b/tests/Utils/Image.resize.phpt
index 56d9b211b..d265c8a1a 100644
--- a/tests/Utils/Image.resize.phpt
+++ b/tests/Utils/Image.resize.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Image crop, resize & flip.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Image;
 use Tester\Assert;
 
diff --git a/tests/Utils/Image.save.phpt b/tests/Utils/Image.save.phpt
index 654f7e4e1..c5b6417f9 100644
--- a/tests/Utils/Image.save.phpt
+++ b/tests/Utils/Image.save.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Image save method exceptions.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Image;
 use Tester\Assert;
 
diff --git a/tests/Utils/Image.send.phpt b/tests/Utils/Image.send.phpt
index f6a543866..07c27de1a 100644
--- a/tests/Utils/Image.send.phpt
+++ b/tests/Utils/Image.send.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Image send method exceptions.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Image;
 use Tester\Assert;
 
diff --git a/tests/Utils/Json.decode().phpt b/tests/Utils/Json.decode().phpt
index 3b407e29f..2663f9df6 100644
--- a/tests/Utils/Json.decode().phpt
+++ b/tests/Utils/Json.decode().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Json::decode()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Json;
 use Tester\Assert;
 
diff --git a/tests/Utils/Json.encode().phpt b/tests/Utils/Json.encode().phpt
index 726f98a37..3f6d41109 100644
--- a/tests/Utils/Json.encode().phpt
+++ b/tests/Utils/Json.encode().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Json::encode()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Json;
 use Tester\Assert;
 
diff --git a/tests/Utils/Object.arrayProperty.phpt b/tests/Utils/Object.arrayProperty.phpt
index 9ead8f7a7..3f2bd036f 100644
--- a/tests/Utils/Object.arrayProperty.phpt
+++ b/tests/Utils/Object.arrayProperty.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object array property.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.closureProperty.phpt b/tests/Utils/Object.closureProperty.phpt
index 4572e2feb..15dcfb4ad 100644
--- a/tests/Utils/Object.closureProperty.phpt
+++ b/tests/Utils/Object.closureProperty.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object closure properties.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.events.phpt b/tests/Utils/Object.events.phpt
index 246b2f17f..50338eefb 100644
--- a/tests/Utils/Object.events.phpt
+++ b/tests/Utils/Object.events.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object event handlers.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.extensionMethod.phpt b/tests/Utils/Object.extensionMethod.phpt
index 25fbc3659..5ca3a57aa 100644
--- a/tests/Utils/Object.extensionMethod.phpt
+++ b/tests/Utils/Object.extensionMethod.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object extension method.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.extensionMethodViaInterface.phpt b/tests/Utils/Object.extensionMethodViaInterface.phpt
index d03d3ae2b..396f08ff3 100644
--- a/tests/Utils/Object.extensionMethodViaInterface.phpt
+++ b/tests/Utils/Object.extensionMethodViaInterface.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object extension method via interface.
  */
 
+declare(strict_types = 1);
+
 use Nette\Object;
 use Tester\Assert;
 
diff --git a/tests/Utils/Object.magicMethod.errors.phpt b/tests/Utils/Object.magicMethod.errors.phpt
index 404c1f59a..41b8e0246 100644
--- a/tests/Utils/Object.magicMethod.errors.phpt
+++ b/tests/Utils/Object.magicMethod.errors.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object magic @methods errors.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.magicMethod.inheritance.phpt b/tests/Utils/Object.magicMethod.inheritance.phpt
index 5e5d6ccfc..d535ac70a 100644
--- a/tests/Utils/Object.magicMethod.inheritance.phpt
+++ b/tests/Utils/Object.magicMethod.inheritance.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object magic @methods inheritance.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.magicMethod.phpt b/tests/Utils/Object.magicMethod.phpt
index b9dcdf7e0..513805476 100644
--- a/tests/Utils/Object.magicMethod.phpt
+++ b/tests/Utils/Object.magicMethod.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object magic @methods.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.magicMethod.types.phpt b/tests/Utils/Object.magicMethod.types.phpt
index dea9a6bb2..2d3f363d9 100644
--- a/tests/Utils/Object.magicMethod.types.phpt
+++ b/tests/Utils/Object.magicMethod.types.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object magic @methods and types.
  */
 
+declare(strict_types = 1);
+
 namespace Test;
 
 use Nette;
diff --git a/tests/Utils/Object.methodGetter.phpt b/tests/Utils/Object.methodGetter.phpt
index d090123df..b31c791d2 100644
--- a/tests/Utils/Object.methodGetter.phpt
+++ b/tests/Utils/Object.methodGetter.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object closure properties.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.property.phpt b/tests/Utils/Object.property.phpt
index eed1bb283..25c2c906d 100644
--- a/tests/Utils/Object.property.phpt
+++ b/tests/Utils/Object.property.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object properties.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.referenceProperty.phpt b/tests/Utils/Object.referenceProperty.phpt
index 1e704268e..888dd684f 100644
--- a/tests/Utils/Object.referenceProperty.phpt
+++ b/tests/Utils/Object.referenceProperty.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object reference to property.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.reflection.phpt b/tests/Utils/Object.reflection.phpt
index 38246bcf2..56a4f39bf 100644
--- a/tests/Utils/Object.reflection.phpt
+++ b/tests/Utils/Object.reflection.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object reflection.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.undeclaredMethod.phpt b/tests/Utils/Object.undeclaredMethod.phpt
index 8470f1453..a2940abbe 100644
--- a/tests/Utils/Object.undeclaredMethod.phpt
+++ b/tests/Utils/Object.undeclaredMethod.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object undeclared method.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/Object.unsetProperty.phpt b/tests/Utils/Object.unsetProperty.phpt
index c125b0a3e..3e529ca63 100644
--- a/tests/Utils/Object.unsetProperty.phpt
+++ b/tests/Utils/Object.unsetProperty.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Object properties.
  */
 
+declare(strict_types = 1);
+
 use Tester\Assert;
 
 require __DIR__ . '/../bootstrap.php';
diff --git a/tests/Utils/ObjectMixin.checkType().phpt b/tests/Utils/ObjectMixin.checkType().phpt
index 9b4ebf2cc..d02363097 100644
--- a/tests/Utils/ObjectMixin.checkType().phpt
+++ b/tests/Utils/ObjectMixin.checkType().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\ObjectMixin::checkType()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\ObjectMixin;
 use Tester\Assert;
 
diff --git a/tests/Utils/Paginator.phpt b/tests/Utils/Paginator.phpt
index 08b29da1c..ef2a3efdd 100644
--- a/tests/Utils/Paginator.phpt
+++ b/tests/Utils/Paginator.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Paginator Base:0 Page:3 test.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Paginator;
 use Tester\Assert;
 
diff --git a/tests/Utils/Random.generate().no-mcrypt.phpt b/tests/Utils/Random.generate().no-mcrypt.phpt
index 3f33c9676..ff19fdaec 100644
--- a/tests/Utils/Random.generate().no-mcrypt.phpt
+++ b/tests/Utils/Random.generate().no-mcrypt.phpt
@@ -5,6 +5,8 @@
  * @phpIni disable_functions=openssl_random_pseudo_bytes,mcrypt_create_iv
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Random;
 use Tester\Assert;
 
diff --git a/tests/Utils/Random.generate().no-openssl.phpt b/tests/Utils/Random.generate().no-openssl.phpt
index 4cf341b27..2d64e749a 100644
--- a/tests/Utils/Random.generate().no-openssl.phpt
+++ b/tests/Utils/Random.generate().no-openssl.phpt
@@ -5,6 +5,8 @@
  * @phpIni disable_functions=openssl_random_pseudo_bytes
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Random;
 use Tester\Assert;
 
diff --git a/tests/Utils/Random.generate().phpt b/tests/Utils/Random.generate().phpt
index fde1ce06d..4036d2498 100644
--- a/tests/Utils/Random.generate().phpt
+++ b/tests/Utils/Random.generate().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Random::generate()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Random;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.Regexp.errors.backtrack.phpt b/tests/Utils/Strings.Regexp.errors.backtrack.phpt
index 7d8a98ccd..cd3d41eac 100644
--- a/tests/Utils/Strings.Regexp.errors.backtrack.phpt
+++ b/tests/Utils/Strings.Regexp.errors.backtrack.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings and RegexpException run-time error.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.Regexp.errors.compilation.phpt b/tests/Utils/Strings.Regexp.errors.compilation.phpt
index c59ddd562..99dee2beb 100644
--- a/tests/Utils/Strings.Regexp.errors.compilation.phpt
+++ b/tests/Utils/Strings.Regexp.errors.compilation.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings and RegexpException compile error.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.Regexp.errors.utf8.phpt b/tests/Utils/Strings.Regexp.errors.utf8.phpt
index 795185841..7f086c391 100644
--- a/tests/Utils/Strings.Regexp.errors.utf8.phpt
+++ b/tests/Utils/Strings.Regexp.errors.utf8.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings and RegexpException run-time error.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.after().phpt b/tests/Utils/Strings.after().phpt
index ab0cf5d72..682a95a6d 100644
--- a/tests/Utils/Strings.after().phpt
+++ b/tests/Utils/Strings.after().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::after()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.before().phpt b/tests/Utils/Strings.before().phpt
index 69675c364..897bcabc1 100644
--- a/tests/Utils/Strings.before().phpt
+++ b/tests/Utils/Strings.before().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::before()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.checkEncoding().phpt b/tests/Utils/Strings.checkEncoding().phpt
index 3c8f737de..a3298b468 100644
--- a/tests/Utils/Strings.checkEncoding().phpt
+++ b/tests/Utils/Strings.checkEncoding().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::checkEncoding()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.chr().phpt b/tests/Utils/Strings.chr().phpt
index acfa9f828..0665137e7 100644
--- a/tests/Utils/Strings.chr().phpt
+++ b/tests/Utils/Strings.chr().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::chr()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.compare().phpt b/tests/Utils/Strings.compare().phpt
index 14ea8be27..60fc0c20b 100644
--- a/tests/Utils/Strings.compare().phpt
+++ b/tests/Utils/Strings.compare().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::compare()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.convertCase.phpt b/tests/Utils/Strings.convertCase.phpt
index c8f2d86e0..817595844 100644
--- a/tests/Utils/Strings.convertCase.phpt
+++ b/tests/Utils/Strings.convertCase.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings and lower, upper, firstLower, firstUpper, capitalize
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.endsWith().phpt b/tests/Utils/Strings.endsWith().phpt
index a2fc4c2ab..4bf556aa7 100644
--- a/tests/Utils/Strings.endsWith().phpt
+++ b/tests/Utils/Strings.endsWith().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::endsWith()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
@@ -11,7 +13,9 @@ use Tester\Assert;
 require __DIR__ . '/../bootstrap.php';
 
 
-Assert::true(Strings::endsWith('123', NULL), "endsWith('123', NULL)");
+Assert::exception(function () {
+	Strings::endsWith('123', NULL);
+}, TypeError::class);
 Assert::true(Strings::endsWith('123', ''), "endsWith('123', '')");
 Assert::true(Strings::endsWith('123', '3'), "endsWith('123', '3')");
 Assert::false(Strings::endsWith('123', '2'), "endsWith('123', '2')");
diff --git a/tests/Utils/Strings.findPrefix().phpt b/tests/Utils/Strings.findPrefix().phpt
index dbb54fd54..b7b80257b 100644
--- a/tests/Utils/Strings.findPrefix().phpt
+++ b/tests/Utils/Strings.findPrefix().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::findPrefix()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.fixEncoding().phpt b/tests/Utils/Strings.fixEncoding().phpt
index cf6396ada..3c4ad3649 100644
--- a/tests/Utils/Strings.fixEncoding().phpt
+++ b/tests/Utils/Strings.fixEncoding().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::fixEncoding()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.indent().phpt b/tests/Utils/Strings.indent().phpt
index 6843d075e..1b63b7d98 100644
--- a/tests/Utils/Strings.indent().phpt
+++ b/tests/Utils/Strings.indent().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::indent()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.indexOf().phpt b/tests/Utils/Strings.indexOf().phpt
index 5cdc26d96..78dc6bdc2 100644
--- a/tests/Utils/Strings.indexOf().phpt
+++ b/tests/Utils/Strings.indexOf().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::indexOf()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.length().phpt b/tests/Utils/Strings.length().phpt
index c808213ac..2f1387ed5 100644
--- a/tests/Utils/Strings.length().phpt
+++ b/tests/Utils/Strings.length().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::length()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.match().phpt b/tests/Utils/Strings.match().phpt
index 10c91a613..d4b674a57 100644
--- a/tests/Utils/Strings.match().phpt
+++ b/tests/Utils/Strings.match().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::match()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.matchAll().phpt b/tests/Utils/Strings.matchAll().phpt
index 2806efad1..c25955e7a 100644
--- a/tests/Utils/Strings.matchAll().phpt
+++ b/tests/Utils/Strings.matchAll().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::matchAll()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.normalize().phpt b/tests/Utils/Strings.normalize().phpt
index da298039e..0f803e2b8 100644
--- a/tests/Utils/Strings.normalize().phpt
+++ b/tests/Utils/Strings.normalize().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::normalize()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.normalizeNewLines().phpt b/tests/Utils/Strings.normalizeNewLines().phpt
index 67565fbaa..3dc590b31 100644
--- a/tests/Utils/Strings.normalizeNewLines().phpt
+++ b/tests/Utils/Strings.normalizeNewLines().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::normalizeNewLines()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.pad.phpt b/tests/Utils/Strings.pad.phpt
index eac150ee7..827f25157 100644
--- a/tests/Utils/Strings.pad.phpt
+++ b/tests/Utils/Strings.pad.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::padLeft() & padRight()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.random().phpt b/tests/Utils/Strings.random().phpt
index 8250be7b9..508bd6bda 100644
--- a/tests/Utils/Strings.random().phpt
+++ b/tests/Utils/Strings.random().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::random()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.replace().errors.callback.phpt b/tests/Utils/Strings.replace().errors.callback.phpt
index 0182053e6..625292d2f 100644
--- a/tests/Utils/Strings.replace().errors.callback.phpt
+++ b/tests/Utils/Strings.replace().errors.callback.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings and error in callback.
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.replace().php53.phpt b/tests/Utils/Strings.replace().php53.phpt
index 7a87fd4ae..1cb3e9297 100644
--- a/tests/Utils/Strings.replace().php53.phpt
+++ b/tests/Utils/Strings.replace().php53.phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::replace()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.replace().phpt b/tests/Utils/Strings.replace().phpt
index 6a09dcf4e..edd4a79a9 100644
--- a/tests/Utils/Strings.replace().phpt
+++ b/tests/Utils/Strings.replace().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::replace()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.reverse().phpt b/tests/Utils/Strings.reverse().phpt
index 1407cad90..d20cb997a 100644
--- a/tests/Utils/Strings.reverse().phpt
+++ b/tests/Utils/Strings.reverse().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::reverse()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.split().phpt b/tests/Utils/Strings.split().phpt
index b77d7a4bd..07f6d1b25 100644
--- a/tests/Utils/Strings.split().phpt
+++ b/tests/Utils/Strings.split().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::split()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.startsWith().phpt b/tests/Utils/Strings.startsWith().phpt
index b6f6559bf..4c3efe82a 100644
--- a/tests/Utils/Strings.startsWith().phpt
+++ b/tests/Utils/Strings.startsWith().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::startsWith()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
@@ -11,7 +13,9 @@ use Tester\Assert;
 require __DIR__ . '/../bootstrap.php';
 
 
-Assert::true(Strings::startsWith('123', NULL), "startsWith('123', NULL)");
+Assert::exception(function () {
+	Strings::startsWith('123', NULL);
+}, TypeError::class);
 Assert::true(Strings::startsWith('123', ''), "startsWith('123', '')");
 Assert::true(Strings::startsWith('123', '1'), "startsWith('123', '1')");
 Assert::false(Strings::startsWith('123', '2'), "startsWith('123', '2')");
diff --git a/tests/Utils/Strings.substring().phpt b/tests/Utils/Strings.substring().phpt
index 69ffd4dc5..b44df4513 100644
--- a/tests/Utils/Strings.substring().phpt
+++ b/tests/Utils/Strings.substring().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::substring()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.toAscii().phpt b/tests/Utils/Strings.toAscii().phpt
index 317a80c1e..1640bb8cf 100644
--- a/tests/Utils/Strings.toAscii().phpt
+++ b/tests/Utils/Strings.toAscii().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::toAscii()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.trim().phpt b/tests/Utils/Strings.trim().phpt
index c71974733..316ac7344 100644
--- a/tests/Utils/Strings.trim().phpt
+++ b/tests/Utils/Strings.trim().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::trim()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.truncate().phpt b/tests/Utils/Strings.truncate().phpt
index 2d2ed933a..d6a638a93 100644
--- a/tests/Utils/Strings.truncate().phpt
+++ b/tests/Utils/Strings.truncate().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::truncate()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Strings.webalize().phpt b/tests/Utils/Strings.webalize().phpt
index dfc516448..654a7dc7d 100644
--- a/tests/Utils/Strings.webalize().phpt
+++ b/tests/Utils/Strings.webalize().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Strings::webalize()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Strings;
 use Tester\Assert;
 
diff --git a/tests/Utils/Validators.assert().phpt b/tests/Utils/Validators.assert().phpt
index bd647b11c..f220f578b 100644
--- a/tests/Utils/Validators.assert().phpt
+++ b/tests/Utils/Validators.assert().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Validators::assert()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Validators;
 use Tester\Assert;
 
diff --git a/tests/Utils/Validators.assertField().phpt b/tests/Utils/Validators.assertField().phpt
index 9e5729fdf..7571e887a 100644
--- a/tests/Utils/Validators.assertField().phpt
+++ b/tests/Utils/Validators.assertField().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Validators::assertField()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Validators;
 use Tester\Assert;
 
diff --git a/tests/Utils/Validators.is().phpt b/tests/Utils/Validators.is().phpt
index 4530ad4a6..14e14335f 100644
--- a/tests/Utils/Validators.is().phpt
+++ b/tests/Utils/Validators.is().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Validators::is()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Validators;
 use Tester\Assert;
 
diff --git a/tests/Utils/Validators.isInRange().phpt b/tests/Utils/Validators.isInRange().phpt
index 77dfc3974..11200ec80 100644
--- a/tests/Utils/Validators.isInRange().phpt
+++ b/tests/Utils/Validators.isInRange().phpt
@@ -4,6 +4,8 @@
  * Test: Nette\Utils\Validators::isInRange()
  */
 
+declare(strict_types = 1);
+
 use Nette\Utils\Validators;
 use Tester\Assert;
 
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index d5af950ff..bcc1b4784 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -3,6 +3,8 @@
 // The Nette Tester command-line runner can be
 // invoked through the command: ../vendor/bin/tester .
 
+declare(strict_types = 1);
+
 if (@!include __DIR__ . '/../vendor/autoload.php') {
 	echo 'Install Nette Tester using `composer install`';
 	exit(1);