Adding rector file generation for automatic refactoring

Author: moufmouf

README.md

@@ -100,6 +100,57 @@ includes:
     - vendor/thecodingmachine/phpstan-safe-rule/phpstan-safe-rule.neon
 ```
 
+## Automated refactoring
+
+You have a large legacy codebase and want to use "Safe-PHP" functions through all you project? PHPStan will help you 
+finding these functions but changing the namespace of the functions one function at a time might be a tedious work.
+
+Hopefully, Safe comes bundled with a "Rector" configuration file. [Rector](https://github.com/rectorphp/rector) is a command-line 
+tool that performs instant refactoring of your application.
+
+First, you need to install Rector:
+
+```bash
+$ composer require --dev rector/rector ^0.3
+```
+
+Now, you simply need to run Rector with this command:
+
+```bash
+vendor/bin/rector process src/ --config vendor/thecodingmachine/safe/rector-migrate.yml
+```
+
+*Note:* do not forget to replace "src/" with the path to your source directory.
+
+**Important:** the refactoring is only performing a "dumb" replacement of functions. It will not modify the way 
+"false" return values are handled. So if your code was already performing error handling, you will have to deal
+with it manually.
+
+Especially, you should look for error handling that was already performed, like:
+
+```php
+if (!mkdir($dirPath)) {
+    // Do something on error
+}
+```
+
+This code will be refactored by Rector to:
+
+```php
+if (!\Safe\mkdir($dirPath)) {
+    // Do something on error
+}
+```
+
+You should then (manually) refactor it to:
+
+```php
+try {
+    \Safe\mkdir($dirPath));
+} catch (\Safe\FilesystemException $e) {
+    // Do something on error
+}
+```
 
 ## Work in progress
 

generator/src/FileCreator.php

@@ -81,6 +81,19 @@ public function generatePhpFile(array $functions, string $path): void
         }
     }
 
+    /**
+     * @param Method[] $functions
+     * @return string[]
+     */
+    private function getFunctionsNameList(array $functions): array
+    {
+        $functionNames = array_map(function (Method $function) {
+            return $function->getFunctionName();
+        }, $functions);
+        $specialCases = require __DIR__.'/../config/specialCasesFunctions.php';
+        return array_merge($functionNames, $specialCases);
+    }
+
 
     /**
      * This function generate a PHP file containing the list of functions we can handle.
@@ -90,11 +103,7 @@ public function generatePhpFile(array $functions, string $path): void
      */
     public function generateFunctionsList(array $functions, string $path): void
     {
-        $functionNames = array_map(function (Method $function) {
-            return $function->getFunctionName();
-        }, $functions);
-        $specialCases = require __DIR__.'/../config/specialCasesFunctions.php';
-        $functionNames = array_merge($functionNames, $specialCases);
+        $functionNames = $this->getFunctionsNameList($functions);
         $stream = fopen($path, 'w');
         if ($stream === false) {
             throw new \RuntimeException('Unable to write to '.$path);
@@ -108,6 +117,30 @@ public function generateFunctionsList(array $functions, string $path): void
         fclose($stream);
     }
 
+    /**
+     * This function generate a rector yml file containing a replacer for all functions
+     *
+     * @param Method[] $functions
+     * @param string $path
+     */
+    public function generateRectorFile(array $functions, string $path): void
+    {
+        $functionNames = $this->getFunctionsNameList($functions);
+        $stream = fopen($path, 'w');
+        if ($stream === false) {
+            throw new \RuntimeException('Unable to write to '.$path);
+        }
+        fwrite($stream, "# This rector file is replacing all core PHP functions with the equivalent \"safe\" functions 
+services:
+  Rector\Rector\Function_\FunctionReplaceRector:
+    \$oldFunctionToNewFunction:
+");
+        foreach ($functionNames as $functionName) {
+            fwrite($stream, '      '.$functionName.": 'Safe\\".$functionName."'\n");
+        }
+        fclose($stream);
+    }
+
 
     public function createExceptionFile(string $moduleName): void
     {

generator/src/GenerateCommand.php

@@ -39,6 +39,7 @@ protected function execute(InputInterface $input, OutputInterface $output)
         //$fileCreator->generateXlsFile($protoFunctions, __DIR__ . '/../generated/lib.xls');
         $fileCreator->generatePhpFile($functions, __DIR__ . '/../../generated/');
         $fileCreator->generateFunctionsList($functions, __DIR__ . '/../../generated/functionsList.php');
+        $fileCreator->generateRectorFile($functions, __DIR__ . '/../../rector-migrate.yml');
 
 
         $modules = [];