feat: add Docker support (exec/run) for PHP CS Fixer

README.md

@@ -217,6 +217,50 @@ per default by adding this to your settings:
     }
 ```
 
+## Docker support
+
+You can run php-cs-fixer inside Docker instead of installing PHP/CS Fixer on the host. Enable it and choose either starting a short-lived container (run) or executing inside an existing container (exec).
+
+Settings (choose one):
+
+Example: exec (default)
+
+```json
+{
+    "php-cs-fixer.docker.enable": true,
+    "php-cs-fixer.docker.mode": "exec",
+    "php-cs-fixer.docker.command": "docker",
+    "php-cs-fixer.docker.container": "php-app",
+    "php-cs-fixer.docker.workspaceFolder": "/app",
+    "php-cs-fixer.docker.execExtraArgs": []
+}
+```
+
+Example: run
+
+```json
+{
+    "php-cs-fixer.docker.enable": true,
+    "php-cs-fixer.docker.mode": "run",
+    "php-cs-fixer.docker.command": "docker",
+    "php-cs-fixer.docker.image": "composer:latest",
+    "php-cs-fixer.docker.workspaceFolder": "/app",
+    "php-cs-fixer.docker.runExtraArgs": []
+}
+```
+
+Notes:
+
+- If `docker.workspaceFolder` is set, the extension mounts your workspace root to that path when using `docker run`. For partial/unsaved content:
+    - docker run: the host temporary directory is mounted to `/tmp` in the container so PHP CS Fixer can read the temp file.
+    - docker exec: partial/unsaved formatting is not supported out-of-the-box because new mounts cannot be added with `docker exec`. Workarounds: save the file first or use `docker run` mode for such cases.
+    If `docker.workspaceFolder` is not set, no mount or workdir is applied; your Dockerfile/image defaults are used.
+- The binary used inside the container comes from `php-cs-fixer.executablePath`. If you're using a `.phar` in the container, set `php-cs-fixer.executablePath` accordingly (e.g., `php /path/in/container/php-cs-fixer.phar`).
+- Config files provided by `php-cs-fixer.config` are automatically mapped to the container path.
+- Mode requirements:
+    exec: set `php-cs-fixer.docker.container` (existing running container name/id).
+    run: set `php-cs-fixer.docker.image` (image name/tag to start the container).
+
 ## Auto fix
 
 ```text

package.json

@@ -130,6 +130,48 @@
           "type": "integer",
           "default": 1,
           "description": "last automatically download php-cs-fixer time, if you want to disable auto download for latest php-cs-fixer.phar set to 0. just for automatically installed user."
+        },
+        "php-cs-fixer.docker.enable": {
+          "type": "boolean",
+          "default": false,
+          "description": "Run php-cs-fixer inside Docker. When enabled, the extension will call php-cs-fixer through Docker instead of the host runtime."
+        },
+        "php-cs-fixer.docker.mode": {
+          "type": "string",
+          "enum": ["run", "exec"],
+          "default": "exec",
+          "description": "Choose how to invoke Docker: 'exec' (default) to run inside an existing container, or 'run' to start a new container for each run."
+        },
+        "php-cs-fixer.docker.command": {
+          "type": "string",
+          "default": "docker",
+          "description": "Docker CLI binary, e.g., 'docker' or 'podman'."
+        },
+        "php-cs-fixer.docker.image": {
+          "type": "string",
+          "default": "",
+          "description": "Docker image to use when mode is 'run'. For example: 'ghcr.io/junstyle/php-cs-fixer:latest' or 'composer:latest'."
+        },
+        "php-cs-fixer.docker.container": {
+          "type": "string",
+          "default": "",
+          "description": "Existing container name or ID when mode is 'exec'."
+        },
+        "php-cs-fixer.docker.workspaceFolder": {
+          "type": "string",
+          "description": "Optional. Workspace mount path inside container when using 'run'. If not set, the extension won't mount or change workdir; image defaults are used."
+        },
+        "php-cs-fixer.docker.runExtraArgs": {
+          "type": "array",
+          "items": { "type": "string" },
+          "default": [],
+          "description": "Extra arguments for 'docker run', e.g., ['--network=host']."
+        },
+        "php-cs-fixer.docker.execExtraArgs": {
+          "type": "array",
+          "items": { "type": "string" },
+          "default": [],
+          "description": "Extra arguments for 'docker exec', e.g., ['-u', '1000:1000']."
         }
       }
     },

src/index.d.ts

@@ -16,4 +16,13 @@ export class PHPCSFixerConfig {
   // fileAutoSave: boolean
   // fileAutoSaveDelay: number
   tmpDir: string
+  // Docker options
+  dockerEnable?: boolean
+  dockerMode?: 'run' | 'exec'
+  dockerCommand?: string
+  dockerImage?: string
+  dockerContainer?: string
+  dockerWorkspaceFolder?: string
+  dockerRunExtraArgs?: string[]
+  dockerExecExtraArgs?: string[]
 }