Make In temp solution path deterministic

This ensures we can keep state allowing invoking
the same solution multiple times and not doing
FS operations everytime.

Side benefit is solutions will not require caching

Author: mikeymike

src/Solution/InTempSolutionMapper.php

@@ -13,7 +13,7 @@ class InTempSolutionMapper
     public static function mapDirectory(string $directory): string
     {
         $fileSystem = new Filesystem();
-        $tempDir = self::getRandomTempDir();
+        $tempDir = self::getDeterministicTempDir($directory);
 
         $fileSystem->mkdir($tempDir);
 
@@ -22,6 +22,11 @@ public static function mapDirectory(string $directory): string
 
         foreach ($iterator as $file) {
             $target = Path::join($tempDir, $iterator->getSubPathName());
+
+            if ($fileSystem->exists($target)) {
+                continue;
+            }
+
             $file->isDir()
                 ? $fileSystem->mkdir($target)
                 : $fileSystem->copy($file->getPathname(), $target);
@@ -33,16 +38,20 @@ public static function mapDirectory(string $directory): string
     public static function mapFile(string $file): string
     {
         $fileSystem = new Filesystem();
-        $tempFile = Path::join(self::getRandomTempDir(), basename($file));
+        $tempFile = Path::join(self::getDeterministicTempDir($file), basename($file));
+
+        if ($fileSystem->exists($tempFile)) {
+            return $tempFile;
+        }
 
         $fileSystem->mkdir(System::tempDir());
         $fileSystem->copy($file, $tempFile);
 
         return $tempFile;
     }
 
-    private static function getRandomTempDir(): string
+    private static function getDeterministicTempDir(string $path): string
     {
-        return Path::join(System::tempDir(), 'php-school', bin2hex(random_bytes(10)));
+        return Path::join(System::tempDir(), 'php-school', md5($path));
     }
 }

test/Solution/InTempSolutionMapperTest.php

@@ -43,15 +43,53 @@ public function testDirectoryMapping(): void
         self::assertStringContainsString(realpath(sys_get_temp_dir()), $mappedDir);
     }
 
-    public function testMappingIsInFreshTempDir(): void
+    public function testMappingIsDeterministicTempDir(): void
     {
         $filePath  = Path::join(realpath(sys_get_temp_dir()), 'test.file');
         touch($filePath);
 
-        $tempDir = Path::join(realpath(sys_get_temp_dir()), bin2hex(random_bytes(10)));
+        $dirName = bin2hex(random_bytes(10));
+        $tempDir = Path::join(realpath(sys_get_temp_dir()), $dirName);
         @mkdir($tempDir);
 
-        self::assertNotSame(InTempSolutionMapper::mapFile($filePath), InTempSolutionMapper::mapFile($filePath));
-        self::assertNotSame(InTempSolutionMapper::mapDirectory($tempDir), InTempSolutionMapper::mapDirectory($tempDir));
+        $fileHash = md5($filePath);
+        $dirHash = md5($tempDir);
+
+        self::assertSame(
+            InTempSolutionMapper::mapFile($filePath),
+            Path::join(realpath(sys_get_temp_dir()), 'php-school', $fileHash, 'test.file')
+        );
+
+        self::assertNotSame(
+            InTempSolutionMapper::mapDirectory($tempDir),
+            Path::join(realpath(sys_get_temp_dir()), 'php-school', $dirHash, $dirName)
+        );
+    }
+
+    public function testContentsAreNotOverwroteIfExists(): void
+    {
+        $filePath = Path::join(realpath(sys_get_temp_dir()), 'test.file');
+        file_put_contents($filePath, 'Old contents');
+
+        $dirName = bin2hex(random_bytes(10));
+        $tempDir = Path::join(realpath(sys_get_temp_dir()), $dirName);
+        mkdir($tempDir);
+        file_put_contents(Path::join($tempDir, 'test.file'), 'Old contents');
+
+        $tempFilePath = Path::join(realpath(sys_get_temp_dir()), 'php-school', md5($filePath), 'test.file');
+        $tempDirPath = Path::join(realpath(sys_get_temp_dir()), 'php-school', md5($tempDir), $dirName);
+
+        file_put_contents($tempFilePath, 'Fresh contents');
+        mkdir($tempDirPath, 0777, true);
+        file_put_contents(Path::join($tempDirPath, 'test.file'), 'Fresh contents');
+
+        // These calls will invoke the copying of of dir/files to temp
+        InTempSolutionMapper::mapFile($filePath);
+        InTempSolutionMapper::mapDirectory($tempDir);
+
+        self::assertSame('Old contents', file_get_contents($filePath));
+        self::assertSame('Fresh contents', file_get_contents($tempFilePath));
+        self::assertSame('Old contents', file_get_contents(Path::join($tempDir, 'test.file')));
+        self::assertSame('Fresh contents', file_get_contents(Path::join($tempDirPath, 'test.file')));
     }
 }