feat: support Module Plugin System

.github/workflows/test.yml

@@ -114,3 +114,35 @@ jobs:
         with:
           working-directory: ${{ matrix.wd }}
           args: --timeout=5m --issues-exit-code=0 ./...
+
+  test-plugins: # make sure the action works on a clean machine with plugins
+    needs: [ build ]
+    strategy:
+      matrix:
+        os:
+          - ubuntu-latest
+          - ubuntu-22.04-arm
+          - macos-latest
+          - windows-latest
+        version:
+          - ""
+          - "latest"
+          - "v2.5"
+          - "v2.5.0"
+    runs-on: ${{ matrix.os }}
+    permissions:
+      contents: read
+      pull-requests: read
+    steps:
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v6
+        with:
+          node-version: 24.x
+      - uses: actions/setup-go@v6
+        with:
+          go-version: oldstable
+      - uses: ./
+        with:
+          version: ${{ matrix.version }}
+          working-directory: sample-plugins
+          args: --timeout=5m --issues-exit-code=0 ./...

README.md

@@ -548,6 +548,13 @@ permissions:
 
 For annotations to work, use the default format output (`text`) and either use [`actions/setup-go`](https://github.com/actions/setup-go) in the job or enable the internal [problem matchers](#problem-matchers).
 
+## Module Plugin System
+
+The action will automatically detect the custom build configuration file `.custom-gcl.yml`,
+build and run the custom version of golangci-lint.
+
+For more information, see [module plugin system](https://golangci-lint.run/docs/plugins/module-plugins/).
+
 ## Performance
 
 The action was implemented with performance in mind: