Add fixer's descriptions (#910)

Author: kubawerlos

src/Fixer/CommentSurroundedBySpacesFixer.php

@@ -27,6 +27,7 @@ public function getDefinition(): FixerDefinitionInterface
             [new CodeSample('<?php
 /*foo*/
 ')],
+            '',
         );
     }
 

src/Fixer/CommentedOutFunctionFixer.php

@@ -36,7 +36,7 @@ public function getDefinition(): FixerDefinitionInterface
             [new CodeSample('<?php
 var_dump($x);
 ')],
-            null,
+            '',
             'when any of the configured functions have side effects or are overwritten',
         );
     }

src/Fixer/ConstructorEmptyBracesFixer.php

@@ -36,6 +36,7 @@ public function __construct(
 ',
                 ),
             ],
+            '',
         );
     }
 

src/Fixer/DataProviderNameFixer.php

@@ -57,7 +57,7 @@ public function dataProvider() {}
 ',
                 ),
             ],
-            null,
+            '',
             'when relying on name of data provider function',
         );
     }

src/Fixer/DataProviderReturnTypeFixer.php

@@ -40,7 +40,7 @@ public function provideSomethingCases(): array {}
 ',
                 ),
             ],
-            null,
+            '',
             'when relying on signature of data provider',
         );
     }

src/Fixer/DataProviderStaticFixer.php

@@ -52,7 +52,7 @@ public function provideSomethingCases() {}
 ',
                 ),
             ],
-            null,
+            '',
             'when `force` is set to `true`',
         );
     }

src/Fixer/DeclareAfterOpeningTagFixer.php

@@ -26,6 +26,7 @@ public function getDefinition(): FixerDefinitionInterface
         return new FixerDefinition(
             'Declare statement for strict types must be placed in the same line, after opening tag.',
             [new CodeSample("<?php\n\$foo;\ndeclare(strict_types=1);\n\$bar;\n")],
+            '',
         );
     }
 

src/Fixer/EmptyFunctionBodyFixer.php

@@ -28,6 +28,7 @@ public function getDefinition(): FixerDefinitionInterface
 {
 }
 ')],
+            '',
         );
     }
 

src/Fixer/InternalClassCasingFixer.php

@@ -36,6 +36,7 @@ public function getDefinition(): FixerDefinitionInterface
         return new FixerDefinition(
             'Classes defined internally by extension or core must be referenced with the correct case.',
             [new CodeSample("<?php\n\$foo = new STDClass();\n")],
+            '',
         );
     }
 

src/Fixer/IssetToArrayKeyExistsFixer.php

@@ -33,7 +33,7 @@ public function getDefinition(): FixerDefinitionInterface
 ',
                 ),
             ],
-            null,
+            '',
             'when array is not defined, is multi-dimensional or behaviour is relying on the null value',
         );
     }