feat: add install-only option

README.md

@@ -302,6 +302,27 @@ with:
 
 </details>
 
+### `install-only`
+
+(optional)
+
+If set to `true`, the action will only install golangci-lint.
+It does not run golangci-lint.
+
+The default value is `false`.
+
+<details>
+<summary>Example</summary>
+
+```yml
+uses: golangci/golangci-lint-action@v8
+with:
+  install-only: true
+  # ...
+```
+
+</details>
+
 ### `github-token`
 
 (optional)

action.yml

@@ -15,6 +15,10 @@ inputs:
     description: "The mode to install golangci-lint. It can be 'binary', 'goinstall', or 'none'."
     default: "binary"
     required: false
+  install-only:
+    description: "Only install golangci-lint. It does not run golangci-lint."
+    default: 'false'
+    required: false
   working-directory:
     description: "golangci-lint working directory. The default is the project root."
     required: false

src/run.ts

@@ -16,13 +16,18 @@ type Env = {
   patchPath: string
 }
 
-async function prepareEnv(): Promise<Env> {
+async function prepareEnv(installOnly: boolean): Promise<Env> {
   const startedAt = Date.now()
 
   // Prepare cache, lint and go in parallel.
   await restoreCache()
 
   const binPath = await install()
+
+  if (installOnly) {
+    return { binPath, patchPath: `` }
+  }
+
   const patchPath = await fetchPatch()
 
   core.info(`Prepared env in ${Date.now() - startedAt}ms`)
@@ -196,8 +201,18 @@ async function getConfigPath(binPath: string, userArgsMap: Map<string, string>,
 
 export async function run(): Promise<void> {
   try {
-    const { binPath, patchPath } = await core.group(`prepare environment`, prepareEnv)
+    const installOnly = core.getBooleanInput(`install-only`, { required: true })
+
+    const { binPath, patchPath } = await core.group(`prepare environment`, () => {
+      return prepareEnv(installOnly)
+    })
+
     core.addPath(path.dirname(binPath))
+
+    if (installOnly) {
+      return
+    }
+
     await core.group(`run golangci-lint`, () => runLint(binPath, patchPath))
   } catch (error) {
     core.error(`Failed to run: ${error}, ${error.stack}`)