Add bare option to checkout action

Fixes #603

README.md

@@ -126,6 +126,10 @@ Please refer to the [release page](https://github.com/actions/checkout/releases/
     # running from unless specified. Example URLs are https://github.com or
     # https://my-ghes-server.example.com
     github-server-url: ''
+
+    # Whether to clone the repository as a bare repository
+    # Default: false
+    bare: ''
 ```
 <!-- end usage -->
 

__test__/git-command-manager.test.ts

@@ -375,4 +375,42 @@ describe('Test fetchDepth and fetchTags options', () => {
       expect.any(Object)
     )
   })
+
+  it('should call execGit with the correct arguments when bare is true', async () => {
+    jest.spyOn(exec, 'exec').mockImplementation(mockExec)
+
+    const workingDirectory = 'test'
+    const lfs = false
+    const doSparseCheckout = false
+    git = await commandManager.createCommandManager(
+      workingDirectory,
+      lfs,
+      doSparseCheckout
+    )
+    const refSpec = ['refspec1', 'refspec2']
+    const options = {
+      filter: 'filterValue',
+      bare: true
+    }
+
+    await git.fetch(refSpec, options)
+
+    expect(mockExec).toHaveBeenCalledWith(
+      expect.any(String),
+      [
+        '-c',
+        'protocol.version=2',
+        'fetch',
+        '--bare',
+        '--no-tags',
+        '--prune',
+        '--no-recurse-submodules',
+        '--filter=filterValue',
+        'origin',
+        'refspec1',
+        'refspec2'
+      ],
+      expect.any(Object)
+    )
+  })
 })

action.yml

@@ -98,6 +98,9 @@ inputs:
   github-server-url:
     description: The base URL for the GitHub instance that you are trying to clone from, will use environment defaults to fetch from the same instance that the workflow is running from unless specified. Example URLs are https://github.com or https://my-ghes-server.example.com
     required: false
+  bare:
+    description: 'Whether to clone the repository as a bare repository'
+    default: false
 outputs:
   ref:
     description: 'The branch, tag or SHA that was checked out'

src/git-source-provider.ts

@@ -110,7 +110,11 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
       !fsHelper.directoryExistsSync(path.join(settings.repositoryPath, '.git'))
     ) {
       core.startGroup('Initializing the repository')
-      await git.init()
+      const initArgs = ['init']
+      if (settings.bare) {
+        initArgs.push('--bare')
+      }
+      await git.execGit(initArgs)
       await git.remoteAdd('origin', repositoryUrl)
       core.endGroup()
     }