diff --git a/src/Cache/Engine/FileEngine.php b/src/Cache/Engine/FileEngine.php
index a5367f373c7..49247cc68c0 100644
--- a/src/Cache/Engine/FileEngine.php
+++ b/src/Cache/Engine/FileEngine.php
@@ -413,7 +413,7 @@ protected function _setKey($key, $createKey = false)
     }
 
     /**
-     * Determine is cache directory is writable
+     * Determine if cache directory is writable
      *
      * @return bool
      */
diff --git a/src/Console/CommandRunner.php b/src/Console/CommandRunner.php
index 894c9ae4dd1..9638d7f1820 100644
--- a/src/Console/CommandRunner.php
+++ b/src/Console/CommandRunner.php
@@ -298,7 +298,7 @@ protected function getShell(ConsoleIo $io, CommandCollection $commands, $name)
     /**
      * Resolve the command name into a name that exists in the collection.
      *
-     * Apply backwards compatibile inflections and aliases.
+     * Apply backwards compatible inflections and aliases.
      *
      * @param \Cake\Console\CommandCollection $commands The command collection to check.
      * @param \Cake\Console\ConsoleIo $io ConsoleIo object for errors.
diff --git a/src/Controller/Controller.php b/src/Controller/Controller.php
index a1bf3aac399..a8fc53fc4e1 100644
--- a/src/Controller/Controller.php
+++ b/src/Controller/Controller.php
@@ -499,7 +499,7 @@ public function enableAutoRender()
     }
 
     /**
-     * Disbale automatic action rendering.
+     * Disable automatic action rendering.
      *
      * @return $this
      * @since 3.6.0
diff --git a/src/Database/FunctionsBuilder.php b/src/Database/FunctionsBuilder.php
index dbcf84e80d1..22a3b71e14b 100644
--- a/src/Database/FunctionsBuilder.php
+++ b/src/Database/FunctionsBuilder.php
@@ -205,7 +205,7 @@ public function extract($part, $expression, $types = [])
      * Add the time unit to the date expression
      *
      * @param string $expression Expression to obtain the date part from.
-     * @param string $value Value to be added. Use negative to substract.
+     * @param string $value Value to be added. Use negative to subtract.
      * @param string $unit Unit of the value e.g. hour or day.
      * @param array $types list of types to bind to the arguments
      * @return \Cake\Database\Expression\FunctionExpression
diff --git a/src/Database/Schema/MysqlSchema.php b/src/Database/Schema/MysqlSchema.php
index 5ca25bf9605..52d7fe204a1 100644
--- a/src/Database/Schema/MysqlSchema.php
+++ b/src/Database/Schema/MysqlSchema.php
@@ -139,7 +139,7 @@ protected function _convertColumn($column)
         }
         if (strpos($col, 'blob') !== false || $col === 'binary') {
             $lengthName = substr($col, 0, -4);
-            $length = isset(TableSchema::$columnLengths[$lengthName]) ? TableSchema::$columnLengths[$lengthName] : null;
+            $length = isset(TableSchema::$columnLengths[$lengthName]) ? TableSchema::$columnLengths[$lengthName] : $length;
 
             return ['type' => TableSchema::TYPE_BINARY, 'length' => $length];
         }
diff --git a/src/Database/Schema/SqliteSchema.php b/src/Database/Schema/SqliteSchema.php
index ffafb8a3047..b22f2a4c673 100644
--- a/src/Database/Schema/SqliteSchema.php
+++ b/src/Database/Schema/SqliteSchema.php
@@ -102,8 +102,8 @@ protected function _convertColumn($column)
         if ($col === 'binary' && $length === 16) {
             return ['type' => TableSchema::TYPE_BINARY_UUID, 'length' => null];
         }
-        if (in_array($col, ['blob', 'clob'])) {
-            return ['type' => TableSchema::TYPE_BINARY, 'length' => null];
+        if (in_array($col, ['blob', 'clob', 'binary'])) {
+            return ['type' => TableSchema::TYPE_BINARY, 'length' => $length];
         }
         if (in_array($col, ['date', 'time', 'timestamp', 'datetime'])) {
             return ['type' => $col, 'length' => null];
diff --git a/src/Datasource/EntityTrait.php b/src/Datasource/EntityTrait.php
index f9035174b2b..854936c0b0e 100644
--- a/src/Datasource/EntityTrait.php
+++ b/src/Datasource/EntityTrait.php
@@ -981,7 +981,7 @@ public function setErrors(array $fields, $overwrite = false)
 
             // String messages are appended to the list,
             // while more complex error structures need their
-            // keys perserved for nested validator.
+            // keys preserved for nested validator.
             if (is_string($error)) {
                 $this->_errors[$f][] = $error;
             } else {
diff --git a/src/Http/Middleware/EncryptedCookieMiddleware.php b/src/Http/Middleware/EncryptedCookieMiddleware.php
index 6555cfd258e..dbb4d3f510c 100644
--- a/src/Http/Middleware/EncryptedCookieMiddleware.php
+++ b/src/Http/Middleware/EncryptedCookieMiddleware.php
@@ -45,7 +45,7 @@ class EncryptedCookieMiddleware
     protected $cookieNames;
 
     /**
-     * Encrpytion key to use.
+     * Encryption key to use.
      *
      * @var string
      */
diff --git a/src/Http/ServerRequestFactory.php b/src/Http/ServerRequestFactory.php
index f86b66b6cb5..3641a9ed306 100644
--- a/src/Http/ServerRequestFactory.php
+++ b/src/Http/ServerRequestFactory.php
@@ -79,7 +79,7 @@ public static function createUri(array $server = [])
      * Build a UriInterface object.
      *
      * Add in some CakePHP specific logic/properties that help
-     * perserve backwards compatibility.
+     * preserve backwards compatibility.
      *
      * @param array $server The server parameters.
      * @param array $headers The normalized headers
diff --git a/src/ORM/Table.php b/src/ORM/Table.php
index 3e663ee5223..3848d53e6df 100644
--- a/src/ORM/Table.php
+++ b/src/ORM/Table.php
@@ -1848,7 +1848,7 @@ public function exists($conditions)
      *   listeners will receive the entity and the options array as arguments. The type
      *   of operation performed (insert or update) can be determined by checking the
      *   entity's method `isNew`, true meaning an insert and false an update.
-     * - Model.afterSaveCommit: Will be triggered after the transaction is commited
+     * - Model.afterSaveCommit: Will be triggered after the transaction is committed
      *   for atomic save, listeners will receive the entity and the options array
      *   as arguments.
      *
diff --git a/src/Routing/RouteBuilder.php b/src/Routing/RouteBuilder.php
index b160391d255..9409f1bcee3 100644
--- a/src/Routing/RouteBuilder.php
+++ b/src/Routing/RouteBuilder.php
@@ -1062,7 +1062,7 @@ public function applyMiddleware(...$names)
                 throw new RuntimeException($message);
             }
         }
-        $this->middleware = array_merge($this->middleware, $names);
+        $this->middleware = array_unique(array_merge($this->middleware, $names));
 
         return $this;
     }
diff --git a/src/Utility/Crypto/Mcrypt.php b/src/Utility/Crypto/Mcrypt.php
index b67c72e91f4..7d0b7a3b743 100644
--- a/src/Utility/Crypto/Mcrypt.php
+++ b/src/Utility/Crypto/Mcrypt.php
@@ -33,7 +33,7 @@ class Mcrypt
      * @param string $key Key to use as the encryption key for encrypted data.
      * @param string $operation Operation to perform, encrypt or decrypt
      * @throws \LogicException When there are errors.
-     * @return string Encrytped binary string data, or decrypted data depending on operation.
+     * @return string Encrypted binary string data, or decrypted data depending on operation.
      * @deprecated 3.3.0 This method will be removed in 4.0.0.
      */
     public static function rijndael($text, $key, $operation)
diff --git a/src/Validation/Validation.php b/src/Validation/Validation.php
index 696f6fe6f0e..72bf6a5ae56 100644
--- a/src/Validation/Validation.php
+++ b/src/Validation/Validation.php
@@ -1373,7 +1373,7 @@ public static function imageSize($file, $options)
      * Validates the image width.
      *
      * @param array $file The uploaded file data from PHP.
-     * @param string $operator Comparision operator.
+     * @param string $operator Comparison operator.
      * @param int $width Min or max width.
      * @return bool
      */
@@ -1391,7 +1391,7 @@ public static function imageWidth($file, $operator, $width)
      * Validates the image width.
      *
      * @param array $file The uploaded file data from PHP.
-     * @param string $operator Comparision operator.
+     * @param string $operator Comparison operator.
      * @param int $height Min or max width.
      * @return bool
      */
diff --git a/tests/TestCase/Database/Schema/MysqlSchemaTest.php b/tests/TestCase/Database/Schema/MysqlSchemaTest.php
index acc55d51622..f8462b60900 100644
--- a/tests/TestCase/Database/Schema/MysqlSchemaTest.php
+++ b/tests/TestCase/Database/Schema/MysqlSchemaTest.php
@@ -123,6 +123,10 @@ public static function convertColumnProvider()
                 'BINARY(16)',
                 ['type' => 'binaryuuid', 'length' => null]
             ],
+            [
+                'BINARY(1)',
+                ['type' => 'binary', 'length' => 1]
+            ],
             [
                 'TEXT',
                 ['type' => 'text', 'length' => null]
diff --git a/tests/TestCase/Database/Schema/SqliteSchemaTest.php b/tests/TestCase/Database/Schema/SqliteSchemaTest.php
index 22935a43edb..6f314f73db7 100644
--- a/tests/TestCase/Database/Schema/SqliteSchemaTest.php
+++ b/tests/TestCase/Database/Schema/SqliteSchemaTest.php
@@ -87,6 +87,10 @@ public static function convertColumnProvider()
                 'BINARY(16)',
                 ['type' => 'binaryuuid', 'length' => null]
             ],
+            [
+                'BINARY(1)',
+                ['type' => 'binary', 'length' => 1]
+            ],
             [
                 'BLOB',
                 ['type' => 'binary', 'length' => null]
diff --git a/tests/TestCase/Database/Schema/SqlserverSchemaTest.php b/tests/TestCase/Database/Schema/SqlserverSchemaTest.php
index 371cd42cd6b..2fb38be7965 100644
--- a/tests/TestCase/Database/Schema/SqlserverSchemaTest.php
+++ b/tests/TestCase/Database/Schema/SqlserverSchemaTest.php
@@ -198,7 +198,7 @@ public static function convertColumnProvider()
                 50,
                 null,
                 null,
-                // Sqlserver returns double lenghts for unicode columns
+                // Sqlserver returns double lengths for unicode columns
                 ['type' => 'string', 'length' => 25]
             ],
             [
diff --git a/tests/TestCase/I18n/I18nTest.php b/tests/TestCase/I18n/I18nTest.php
index 332f75e97cc..9255616e466 100644
--- a/tests/TestCase/I18n/I18nTest.php
+++ b/tests/TestCase/I18n/I18nTest.php
@@ -266,7 +266,7 @@ public function testBasicTranslateFunction()
     }
 
     /**
-     * Tests the __() functions with explict null params
+     * Tests the __() functions with explicit null params
      *
      * @return void
      */
diff --git a/tests/TestCase/ORM/Behavior/TranslateBehaviorTest.php b/tests/TestCase/ORM/Behavior/TranslateBehaviorTest.php
index 1a460fffa0a..2d0393ce5e6 100644
--- a/tests/TestCase/ORM/Behavior/TranslateBehaviorTest.php
+++ b/tests/TestCase/ORM/Behavior/TranslateBehaviorTest.php
@@ -173,7 +173,7 @@ public function testFindTranslationsFormatResultsIteration()
 
     /**
      * Tests that fields from a translated model use the I18n class locale
-     * and that it propogates to associated models
+     * and that it propagates to associated models
      *
      * @return void
      */
diff --git a/tests/TestCase/ORM/TableTest.php b/tests/TestCase/ORM/TableTest.php
index 8a7a52addc2..25d1c06dc6f 100644
--- a/tests/TestCase/ORM/TableTest.php
+++ b/tests/TestCase/ORM/TableTest.php
@@ -4986,7 +4986,7 @@ public function testReplaceHasManyOnErrorDependentCascadeCallbacks()
     }
 
     /**
-     * Integration test for replacing entities with HasMany and an empty target list. The transaction must be successfull
+     * Integration test for replacing entities with HasMany and an empty target list. The transaction must be successful
      *
      * @return void
      */
@@ -5028,7 +5028,7 @@ public function testReplaceHasManyEmptyList()
     }
 
     /**
-     * Integration test for replacing entities with HasMany and no already persisted entities. The transaction must be successfull.
+     * Integration test for replacing entities with HasMany and no already persisted entities. The transaction must be successful.
      * Replace operation should prevent considering 0 changed records an error when they are not found in the table
      *
      * @return void
@@ -6542,7 +6542,7 @@ public function testSetEntitySource()
 
     /**
      * Tests that passing a coned entity that was marked as new to save() will
-     * actaully save it as a new entity
+     * actually save it as a new entity
      *
      * @group save
      * @return void
diff --git a/tests/TestCase/Routing/Route/RouteTest.php b/tests/TestCase/Routing/Route/RouteTest.php
index 0687d0dc907..d2d979ceafa 100644
--- a/tests/TestCase/Routing/Route/RouteTest.php
+++ b/tests/TestCase/Routing/Route/RouteTest.php
@@ -582,7 +582,7 @@ public function testComplexRouteCompilingAndParsing()
         $this->assertRegExp($result, '/source/view');
         $this->assertRegExp($result, '/source/view/other/params');
         $this->assertNotRegExp($result, '/chaw_test/wiki');
-        $this->assertNotRegExp($result, '/source/wierd_action');
+        $this->assertNotRegExp($result, '/source/weird_action');
     }
 
     /**
diff --git a/tests/TestCase/Routing/RouteBuilderTest.php b/tests/TestCase/Routing/RouteBuilderTest.php
index d763b3e8519..b31cb699cef 100644
--- a/tests/TestCase/Routing/RouteBuilderTest.php
+++ b/tests/TestCase/Routing/RouteBuilderTest.php
@@ -1081,6 +1081,25 @@ public function testApplyMiddlewareMerges()
         $this->assertAttributeEquals(['test', 'test2'], 'middleware', $routes);
     }
 
+    /**
+     * Test that applyMiddleware() uses unique middleware set
+     *
+     * @return void
+     */
+    public function testApplyMiddlewareUnique()
+    {
+        $func = function () {
+        };
+        $routes = new RouteBuilder($this->collection, '/api');
+        $routes->registerMiddleware('test', $func)
+            ->registerMiddleware('test2', $func);
+
+        $routes->applyMiddleware('test', 'test2');
+        $routes->applyMiddleware('test2', 'test');
+
+        $this->assertAttributeEquals(['test', 'test2'], 'middleware', $routes);
+    }
+
     /**
      * Test applying middleware results in middleware attached to the route.
      *
diff --git a/tests/TestCase/Utility/HashTest.php b/tests/TestCase/Utility/HashTest.php
index 8cb2ae1e884..814da1507f1 100644
--- a/tests/TestCase/Utility/HashTest.php
+++ b/tests/TestCase/Utility/HashTest.php
@@ -1189,7 +1189,7 @@ public function testExtractWildcard()
     }
 
     /**
-     * Test the attribute presense selector.
+     * Test the attribute presence selector.
      *
      * @dataProvider articleDataSets
      * @return void
diff --git a/tests/TestCase/Utility/TextTest.php b/tests/TestCase/Utility/TextTest.php
index 1b773bf9946..4f0129c787f 100644
--- a/tests/TestCase/Utility/TextTest.php
+++ b/tests/TestCase/Utility/TextTest.php
@@ -468,7 +468,7 @@ public function testWrapIndent()
     }
 
     /**
-     * test wrapBlock() indentical to wrap()
+     * test wrapBlock() identical to wrap()
      *
      * @return void
      */
diff --git a/tests/TestCase/Validation/ValidationTest.php b/tests/TestCase/Validation/ValidationTest.php
index c7f914ea68d..22f6bc4f0c0 100644
--- a/tests/TestCase/Validation/ValidationTest.php
+++ b/tests/TestCase/Validation/ValidationTest.php
@@ -1978,7 +1978,7 @@ public function testEmail()
      */
     public function testEmailDeep()
     {
-        $this->skipIf((bool)gethostbynamel('example.abcd'), 'Your DNS service responds for non-existant domains, skipping deep email checks.');
+        $this->skipIf((bool)gethostbynamel('example.abcd'), 'Your DNS service responds for non-existent domains, skipping deep email checks.');
 
         $this->assertTrue(Validation::email('abc.efg@cakephp.org', true));
         $this->assertFalse(Validation::email('abc.efg@caphpkeinvalid.com', true));
diff --git a/tests/TestCase/View/Helper/PaginatorHelperTest.php b/tests/TestCase/View/Helper/PaginatorHelperTest.php
index b740c522a8d..99122c9e566 100644
--- a/tests/TestCase/View/Helper/PaginatorHelperTest.php
+++ b/tests/TestCase/View/Helper/PaginatorHelperTest.php
@@ -842,7 +842,7 @@ public function testUrlGenerationResetsToPage1($field, $options, $expected)
     /**
      * Returns data sets of:
      *  * the name of the field being sorted on
-     *  * url paramters to pass to paginator sort
+     *  * url parameters to pass to paginator sort
      *  * expected result as a string
      *
      * @return array
diff --git a/tests/TestCase/View/ViewTest.php b/tests/TestCase/View/ViewTest.php
index adeb57830c7..765a9d28f16 100644
--- a/tests/TestCase/View/ViewTest.php
+++ b/tests/TestCase/View/ViewTest.php
@@ -1941,7 +1941,7 @@ public function testExtendMissingElement()
     }
 
     /**
-     * Test extend() preceeded by an element()
+     * Test extend() preceded by an element()
      *
      * @return void
      */
@@ -1958,7 +1958,7 @@ public function testExtendWithElementBeforeExtend()
     }
 
     /**
-     * Test extend() preceeded by an element()
+     * Test extend() preceded by an element()
      *
      * @return void
      */