make classes final

.travis.yml

@@ -6,7 +6,6 @@ php:
   - 7.1
   - 7.2
   - 7.3
-  - nightly
 
 os: linux
 
@@ -67,6 +66,7 @@ jobs:
       env: COMPOSER_FLAGS=""
       script:
         - composer validate
+        - composer normalize --dry-run
 
     - stage: static code analysis
       php: 7.1

composer.json

@@ -19,19 +19,20 @@
     }
   ],
   "require": {
-    "ext-json": "*",
     "php": "^7.1",
+    "ext-json": "*",
     "daverandom/exceptional-json": "^1.0.1"
   },
   "require-dev": {
     "friendsofphp/php-cs-fixer": "^2.13",
+    "localheinz/composer-normalize": "^1.0.0",
+    "localheinz/phpstan-rules": "^0.4",
     "pepakriz/phpstan-exception-rules": "^0.3",
     "phpstan/phpstan": "^0.10",
-    "phpstan/phpstan-beberlei-assert": "^0.10",
     "phpstan/phpstan-deprecation-rules": "^0.10",
     "phpstan/phpstan-phpunit": "^0.10",
     "phpstan/phpstan-strict-rules": "^0.10",
-    "phpunit/phpunit": "^7.3",
+    "phpunit/phpunit": "^7.4",
     "squizlabs/php_codesniffer": "^3.3"
   },
   "autoload": {

phpstan.neon

@@ -3,16 +3,17 @@ parameters:
     - %currentWorkingDirectory%/vendor/squizlabs/php_codesniffer/autoload.php
     - %currentWorkingDirectory%/vendor/squizlabs/php_codesniffer/src/Util/Tokens.php
   includes:
-  	- vendor/phpstan/phpstan-strict-rules/rules.neon
-  	- vendor/phpstan/phpstan-phpunit/extension.neon
-  	- vendor/phpstan/phpstan-phpunit/rules.neon
-  	- vendor/pepakriz/phpstan-exception-rules/extension.neon
-  	- vendor/phpstan/phpstan-deprecation-rules/rules.neon
-  	- vendor/phpstan/phpstan-beberlei-assert/extension.neon
+    - vendor/phpstan/phpstan-strict-rules/rules.neon
+    - vendor/phpstan/phpstan-phpunit/extension.neon
+    - vendor/phpstan/phpstan-phpunit/rules.neon
+    - vendor/pepakriz/phpstan-exception-rules/extension.neon
+    - vendor/phpstan/phpstan-deprecation-rules/rules.neon
+    - vendor/phpstan/phpstan-beberlei-assert/extension.neon
+    - vendor/localheinz/phpstan-rules/rules.neon
   parameters:
-  	exceptionRules:
-  		reportUnusedCatchesOfUncheckedExceptions: false
-  		uncheckedExceptions: []
+    exceptionRules:
+      reportUnusedCatchesOfUncheckedExceptions: false
+      uncheckedExceptions: []
   excludes_analyse:
     - */tests/*/data/*
   ignoreErrors:

src/Json.php

@@ -11,7 +11,7 @@
 declare(strict_types = 1);
 namespace JsonClass;
 
-class Json
+final class Json
 {
     /**
      * Returns the JSON representation of a value.

tests/JsonTest.php

@@ -22,7 +22,7 @@
 use JsonClass\Json;
 use PHPUnit\Framework\TestCase;
 
-class JsonTest extends TestCase
+final class JsonTest extends TestCase
 {
     /**
      * @var Json