fix default branch for .wiki and when using ssh (#284)

src/git-command-manager.ts

@@ -25,6 +25,7 @@ export interface IGitCommandManager {
   ): Promise<void>
   configExists(configKey: string, globalConfig?: boolean): Promise<boolean>
   fetch(refSpec: string[], fetchDepth?: number): Promise<void>
+  getDefaultBranch(repositoryUrl: string): Promise<string>
   getWorkingDirectory(): string
   init(): Promise<void>
   isDetached(): Promise<boolean>
@@ -195,6 +196,34 @@ class GitCommandManager {
     })
   }
 
+  async getDefaultBranch(repositoryUrl: string): Promise<string> {
+    let output: GitOutput | undefined
+    await retryHelper.execute(async () => {
+      output = await this.execGit([
+        'ls-remote',
+        '--quiet',
+        '--exit-code',
+        '--symref',
+        repositoryUrl,
+        'HEAD'
+      ])
+    })
+
+    if (output) {
+      // Satisfy compiler, will always be set
+      for (let line of output.stdout.trim().split('\n')) {
+        line = line.trim()
+        if (line.startsWith('ref:') || line.endsWith('HEAD')) {
+          return line
+            .substr('ref:'.length, line.length - 'ref:'.length - 'HEAD'.length)
+            .trim()
+        }
+      }
+    }
+
+    throw new Error('Unexpected output when retrieving default branch')
+  }
+
   getWorkingDirectory(): string {
     return this.workingDirectory
   }

src/git-source-provider.ts

@@ -19,17 +19,6 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
   )
   const repositoryUrl = urlHelper.getFetchUrl(settings)
 
-  // Determine the default branch
-  if (!settings.ref && !settings.commit) {
-    core.startGroup('Determining the default branch')
-    settings.ref = await githubApiHelper.getDefaultBranch(
-      settings.authToken,
-      settings.repositoryOwner,
-      settings.repositoryName
-    )
-    core.endGroup()
-  }
-
   // Remove conflicting file path
   if (fsHelper.fileExistsSync(settings.repositoryPath)) {
     await io.rmRF(settings.repositoryPath)
@@ -114,6 +103,21 @@ export async function getSource(settings: IGitSourceSettings): Promise<void> {
     await authHelper.configureAuth()
     core.endGroup()
 
+    // Determine the default branch
+    if (!settings.ref && !settings.commit) {
+      core.startGroup('Determining the default branch')
+      if (settings.sshKey) {
+        settings.ref = await git.getDefaultBranch(repositoryUrl)
+      } else {
+        settings.ref = await githubApiHelper.getDefaultBranch(
+          settings.authToken,
+          settings.repositoryOwner,
+          settings.repositoryName
+        )
+      }
+      core.endGroup()
+    }
+
     // LFS install
     if (settings.lfs) {
       await git.lfsInstall()

src/github-api-helper.ts

@@ -19,6 +19,12 @@ export async function downloadRepository(
   commit: string,
   repositoryPath: string
 ): Promise<void> {
+  // Determine the default branch
+  if (!ref && !commit) {
+    core.info('Determining the default branch')
+    ref = await getDefaultBranch(authToken, owner, repo)
+  }
+
   // Download the archive
   let archiveData = await retryHelper.execute(async () => {
     core.info('Downloading the archive')
@@ -78,17 +84,25 @@ export async function getDefaultBranch(
   return await retryHelper.execute(async () => {
     core.info('Retrieving the default branch name')
     const octokit = new github.GitHub(authToken)
-    const response = await octokit.repos.get({owner, repo})
-    if (response.status != 200) {
-      throw new Error(
-        `Unexpected response from GitHub API. Status: ${response.status}, Data: ${response.data}`
-      )
+    let result: string
+    try {
+      // Get the default branch from the repo info
+      const response = await octokit.repos.get({owner, repo})
+      result = response.data.default_branch
+      assert.ok(result, 'default_branch cannot be empty')
+    } catch (err) {
+      // Handle .wiki repo
+      if (err['status'] === 404 && repo.toUpperCase().endsWith('.WIKI')) {
+        result = 'master'
+      }
+      // Otherwise error
+      else {
+        throw err
+      }
     }
 
     // Print the default branch
-    let result = response.data.default_branch
     core.info(`Default branch '${result}'`)
-    assert.ok(result, 'default_branch cannot be empty')
 
     // Prefix with 'refs/heads'
     if (!result.startsWith('refs/')) {