Fix errors reported by phpstan.

src/Console/CommandRunner.php

@@ -257,7 +257,9 @@ public function eventManager(EventManager $events = null)
     public function setEventManager(EventManager $events)
     {
         if ($this->app instanceof PluginApplicationInterface) {
-            return $this->app->setEventManager($events);
+            $this->app->setEventManager($events);
+
+            return $this;
         }
 
         throw new InvalidArgumentException('Cannot set the event manager, the application does not support events.');

src/Core/Plugin.php

@@ -30,7 +30,7 @@ class Plugin
     /**
      * Holds a list of all loaded plugins and their configuration
      *
-     * @var \Cake\Core\PluginCollection
+     * @var \Cake\Core\PluginCollection|null
      */
     protected static $plugins;
 

src/Core/PluginCollection.php

@@ -48,7 +48,9 @@ class PluginCollection implements Iterator, Countable
     protected $names = [];
 
     /**
-     * @var null|string
+     * Iterator position.
+     *
+     * @var int
      */
     protected $position = 0;
 

src/Database/Statement/StatementDecorator.php

@@ -300,7 +300,7 @@ public function bind($params, $types)
      *
      * @param string|null $table table name or sequence to get last insert value from
      * @param string|null $column the name of the column representing the primary key
-     * @return string
+     * @return string|int
      */
     public function lastInsertId($table = null, $column = null)
     {

src/Filesystem/Folder.php

@@ -923,7 +923,7 @@ public function errors($reset = true)
      * Get the real path (taking ".." and such into account)
      *
      * @param string $path Path to resolve
-     * @return string|bool The resolved path
+     * @return string|false The resolved path
      */
     public function realpath($path)
     {

src/Http/Client.php

@@ -122,7 +122,7 @@ class Client
      * Cookies are indexed by the cookie's domain or
      * request host name.
      *
-     * @var \Cake\Http\Client\CookieCollection
+     * @var \Cake\Http\Cookie\CookieCollection
      */
     protected $_cookies;
 

src/Http/Client/Response.php

@@ -440,7 +440,7 @@ public function getCookieCollection()
      * Get the value of a single cookie.
      *
      * @param string $name The name of the cookie value.
-     * @return string|null Either the cookie's value or null when the cookie is undefined.
+     * @return string|array|null Either the cookie's value or null when the cookie is undefined.
      */
     public function getCookie($name)
     {

src/Http/Server.php

@@ -210,7 +210,9 @@ public function eventManager(EventManager $events = null)
     public function setEventManager(EventManager $events)
     {
         if ($this->app instanceof PluginApplicationInterface) {
-            return $this->app->setEventManager($events);
+            $this->app->setEventManager($events);
+
+            return $this;
         }
 
         throw new InvalidArgumentException('Cannot set the event manager, the application does not support events.');

src/Http/ServerRequest.php

@@ -777,8 +777,7 @@ public function clearDetectorCache()
     /**
      * Worker for the public is() function
      *
-     * @param string|array $type The type of request you want to check. If an array
-     *   this method will return true if the request matches any type.
+     * @param string $type The type of request you want to check.
      * @param array $args Array of custom detector arguments.
      * @return bool Whether or not the request is the type you are checking.
      */

src/ORM/Association.php

@@ -502,7 +502,7 @@ public function getConditions()
      * @deprecated 3.4.0 Use setConditions()/getConditions() instead.
      * @param array|null $conditions list of conditions to be used
      * @see \Cake\Database\Query::where() for examples on the format of the array
-     * @return array
+     * @return array|callable
      */
     public function conditions($conditions = null)
     {

src/ORM/Table.php

@@ -749,7 +749,9 @@ public function displayField($key = null)
             'Use setDisplayField()/getDisplayField() instead.'
         );
         if ($key !== null) {
-            return $this->setDisplayField($key);
+            $this->setDisplayField($key);
+
+            return $key;
         }
 
         return $this->getDisplayField();
@@ -931,6 +933,7 @@ public function behaviors()
      */
     public function getBehavior($name)
     {
+        /** @var \Cake\ORM\Behavior $behavior */
         $behavior = $this->_behaviors->get($name);
         if ($behavior === null) {
             throw new InvalidArgumentException(sprintf(
@@ -1126,7 +1129,10 @@ public function belongsTo($associated, array $options = [])
     {
         $options += ['sourceTable' => $this];
 
-        return $this->_associations->load(BelongsTo::class, $associated, $options);
+        /** @var \Cake\ORM\Association\BelongsTo $association */
+        $association = $this->_associations->load(BelongsTo::class, $associated, $options);
+
+        return $association;
     }
 
     /**
@@ -1169,7 +1175,10 @@ public function hasOne($associated, array $options = [])
     {
         $options += ['sourceTable' => $this];
 
-        return $this->_associations->load(HasOne::class, $associated, $options);
+        /** @var \Cake\ORM\Association\HasOne $association */
+        $association = $this->_associations->load(HasOne::class, $associated, $options);
+
+        return $association;
     }
 
     /**
@@ -1218,7 +1227,10 @@ public function hasMany($associated, array $options = [])
     {
         $options += ['sourceTable' => $this];
 
-        return $this->_associations->load(HasMany::class, $associated, $options);
+        /** @var \Cake\ORM\Association\HasMany $association */
+        $association = $this->_associations->load(HasMany::class, $associated, $options);
+
+        return $association;
     }
 
     /**
@@ -1269,7 +1281,10 @@ public function belongsToMany($associated, array $options = [])
     {
         $options += ['sourceTable' => $this];
 
-        return $this->_associations->load(BelongsToMany::class, $associated, $options);
+        /** @var \Cake\ORM\Association\BelongsToMany $association */
+        $association = $this->_associations->load(BelongsToMany::class, $associated, $options);
+
+        return $association;
     }
 
     /**

src/Validation/ValidationSet.php

@@ -54,7 +54,7 @@ class ValidationSet implements ArrayAccess, IteratorAggregate, Countable
      *
      * @param bool|string|callable|null $validatePresent Deprecated since 3.6.0 ValidationSet::isPresenceRequired() is deprecated as a setter
      * Use ValidationSet::requirePresence() instead.
-     * @return bool|string
+     * @return bool|string|callable
      */
     public function isPresenceRequired($validatePresent = null)
     {

src/View/Helper.php

@@ -181,6 +181,7 @@ protected function _confirm($message, $okCode, $cancelCode = '', $options = [])
         // We cannot change the key here in 3.x, but the behavior is inverted in this case
         $escape = isset($options['escape']) && $options['escape'] === false;
         if ($escape) {
+            /** @var string $confirm */
             $confirm = h($confirm);
         }
 

src/View/Helper/UrlHelper.php

@@ -55,6 +55,7 @@ public function build($url = null, $options = false)
         /** @var string $url */
         $url = Router::url($url, $options['fullBase']);
         if ($options['escape']) {
+            /** @var string $url */
             $url = h($url);
         }
 
@@ -210,7 +211,10 @@ protected function _encodeUrl($url)
         $parts = array_map('rawurlencode', $parts);
         $encoded = implode('/', $parts);
 
-        return h(str_replace($path, $encoded, $url));
+        /** @var string $url */
+        $url = h(str_replace($path, $encoded, $url));
+
+        return $url;
     }
 
     /**

src/View/ViewBuilder.php

@@ -254,7 +254,7 @@ public function setPlugin($name)
     /**
      * Gets the plugin name to use.
      *
-     * @return string
+     * @return string|null|false
      */
     public function getPlugin()
     {
@@ -267,7 +267,7 @@ public function getPlugin()
      * @deprecated 3.4.0 Use setPlugin()/getPlugin() instead.
      * @param string|null|false $name Plugin name. If null returns current plugin.
      *   Use false to remove the current plugin name.
-     * @return string|$this
+     * @return string|false|null|$this
      */
     public function plugin($name = null)
     {
@@ -341,7 +341,7 @@ public function setTheme($theme)
     /**
      * Gets the view theme to use.
      *
-     * @return string
+     * @return string|null|false
      */
     public function getTheme()
     {
@@ -354,7 +354,7 @@ public function getTheme()
      * @deprecated 3.4.0 Use setTheme()/getTheme() instead.
      * @param string|null|false $theme Theme name. If null returns current theme.
      *   Use false to remove the current theme.
-     * @return string|$this
+     * @return string|false|null|$this
      */
     public function theme($theme = null)
     {