Fix retrieving git worktree path

src/Locator/GitRepositoryDirLocator.php

@@ -35,13 +35,55 @@ public function locate(string $gitDir): string
 
         $gitRepositoryDir = $matches[1];
 
-        if ($this->filesystem->isAbsolutePath($gitRepositoryDir)) {
-            return $gitRepositoryDir;
+        if ($this->isWorktree($gitRepositoryDir)) {
+            return $this->locateWorktreeRoot($gitRepositoryDir);
         }
 
         return $this->filesystem->buildPath(
             dirname($gitDir),
             $gitRepositoryDir
         );
     }
+
+    /**
+     * If a given path (from gitdir value) is absolute and there is a commondir file, it is
+     * a worktree.
+     */
+    private function isWorktree(string $gitDir): bool
+    {
+        return $this->filesystem->isAbsolutePath($gitDir)
+            && $this->filesystem->isFile($gitDir.DIRECTORY_SEPARATOR.'commondir');
+    }
+
+    /**
+     * Retreiving repository dir for worktree nominally returns path to the configured worktree,
+     * which does not hold hooks. We need to resolve the actual repository root.
+     *
+     * Example directory structure:
+     * ```
+     * /project
+     *   .git/
+     *     .git/hooks/
+     *     .git/worktrees/
+     *       worktree1
+     *         commondir: relative path to /project/.git
+     * /worktree1
+     *   .git: file with path to /project/.git/worktrees/worktree1
+     * ```
+     */
+    private function locateWorktreeRoot(string $gitRepositoryDir): string
+    {
+        $worktreeRelativeRoot = trim(
+            $this->filesystem->readPath(
+                $gitRepositoryDir.DIRECTORY_SEPARATOR.'commondir'
+            )
+        );
+
+        return $this->filesystem->realpath(
+            $this->filesystem->makePathAbsolute(
+                $worktreeRelativeRoot,
+                $gitRepositoryDir
+            )
+        );
+    }
 }

test/Unit/Locator/GitRepositoryDirLocatorTest.php

@@ -31,7 +31,7 @@ protected function setUp(): void
 
         $this->filesystem               = new Filesystem();
         $this->locator                  = new GitRepositoryDirLocator($this->filesystem);
-        $this->gitDir = $this->workspace . DIRECTORY_SEPARATOR . '.git';
+        $this->gitDir                   = $this->workspace . DIRECTORY_SEPARATOR . '.git';
     }
 
     /**
@@ -69,7 +69,11 @@ public function it_can_passthrough_git_dir_path_if_file_is_not_parseable(): void
      */
     public function it_can_locate_git_dir_in_workspaces(): void
     {
-        $this->filesystem->dumpFile($this->gitDir, 'gitdir: /dev/null');
-        $this->assertEquals('/dev/null', $this->locator->locate($this->gitDir));
+        $ourWorktreeProject = $this->workspace.'/project1/';
+        $worktreeGitRoot = $this->gitDir.'/worktrees/worktree1/';
+        mkdir($worktreeGitRoot, 0777, true);
+        $this->filesystem->dumpFile($worktreeGitRoot.'/commondir', '../..');
+        $this->filesystem->dumpFile($ourWorktreeProject.'/.git', 'gitdir: '.$this->gitDir.'/worktrees/worktree1');
+        $this->assertEquals($this->gitDir, $this->locator->locate($this->gitDir));
     }
 }