Pint --diff arg

Author: erikn69

Diff for: README.md

@@ -6,9 +6,9 @@ GitHub Action implementation of the [Laravel Pint](https://github.com/laravel/pi
 
 Use with [GitHub Actions](https://github.com/features/actions)
 
-_.github/workflows/pint.yml
+`_.github/workflows/pint.yml`
 
-```
+```yml
 name: PHP Linting
 on: pull_request
 jobs:
@@ -25,6 +25,7 @@ jobs:
             configPath: "vendor/my-company/coding-style/pint.json"
             pintVersion: 1.8.0
             onlyDirty: true
+            # onlyDiff: "origin/main"
 
 ```
 ℹ️ Starting from version 2 you can specify the Pint version to be used by specifying a `pintVersion` in your configuration file.

Diff for: action.yml

@@ -21,6 +21,10 @@ inputs:
   onlyDirty:
     description: "only format changed files"
     required: false
+
+  onlyDiff:
+    description: "only format changed files that differ from the provided branch"
+    required: false
 
   pintVersion:
     description: "laravel/pint composer version to install a specific version."

Diff for: entrypoint.sh

@@ -31,6 +31,11 @@ if [[ "${INPUT_PRESET}" ]]; then
   pint_command+=" --preset ${INPUT_PRESET}"
 fi
 
+if [[ "${INPUT_ONLYDIFF}" ]]; then
+  pint_command+=" --diff=${INPUT_ONLYDIFF}"
+  INPUT_ONLYDIRTY=false
+fi
+
 if [[ "${INPUT_ONLYDIRTY}" == true ]]; then
   pint_command+=" --dirty"
 fi