1 files changed, 92 insertions, 0 deletions
diff --git a/src/github-api-helper.ts b/src/github-api-helper.ts
new file mode 100644
index 0000000..b370d06
--- /dev/null
+++ b/src/github-api-helper.ts
@@ -0,0 +1,92 @@
+import * as assert from 'assert'
+import * as core from '@actions/core'
+import * as fs from 'fs'
+import * as github from '@actions/github'
+import * as io from '@actions/io'
+import * as path from 'path'
+import * as retryHelper from './retry-helper'
+import * as toolCache from '@actions/tool-cache'
+import {default as uuid} from 'uuid/v4'
+import {ReposGetArchiveLinkParams} from '@octokit/rest'
+
+const IS_WINDOWS = process.platform === 'win32'
+
+export async function downloadRepository(
+  accessToken: string,
+  owner: string,
+  repo: string,
+  ref: string,
+  commit: string,
+  repositoryPath: string
+): Promise<void> {
+  // Download the archive
+  let archiveData = await retryHelper.execute(async () => {
+    core.info('Downloading the archive')
+    return await downloadArchive(accessToken, owner, repo, ref, commit)
+  })
+
+  // Write archive to disk
+  core.info('Writing archive to disk')
+  const uniqueId = uuid()
+  const archivePath = path.join(repositoryPath, `${uniqueId}.tar.gz`)
+  await fs.promises.writeFile(archivePath, archiveData)
+  archiveData = Buffer.from('') // Free memory
+
+  // Extract archive
+  core.info('Extracting the archive')
+  const extractPath = path.join(repositoryPath, uniqueId)
+  await io.mkdirP(extractPath)
+  if (IS_WINDOWS) {
+    await toolCache.extractZip(archivePath, extractPath)
+  } else {
+    await toolCache.extractTar(archivePath, extractPath)
+  }
+  io.rmRF(archivePath)
+
+  // Determine the path of the repository content. The archive contains
+  // a top-level folder and the repository content is inside.
+  const archiveFileNames = await fs.promises.readdir(extractPath)
+  assert.ok(
+    archiveFileNames.length == 1,
+    'Expected exactly one directory inside archive'
+  )
+  const archiveVersion = archiveFileNames[0] // The top-level folder name includes the short SHA
+  core.info(`Resolved version ${archiveVersion}`)
+  const tempRepositoryPath = path.join(extractPath, archiveVersion)
+
+  // Move the files
+  for (const fileName of await fs.promises.readdir(tempRepositoryPath)) {
+    const sourcePath = path.join(tempRepositoryPath, fileName)
+    const targetPath = path.join(repositoryPath, fileName)
+    if (IS_WINDOWS) {
+      await io.cp(sourcePath, targetPath, {recursive: true}) // Copy on Windows (Windows Defender may have a lock)
+    } else {
+      await io.mv(sourcePath, targetPath)
+    }
+  }
+  io.rmRF(extractPath)
+}
+
+async function downloadArchive(
+  accessToken: string,
+  owner: string,
+  repo: string,
+  ref: string,
+  commit: string
+): Promise<Buffer> {
+  const octokit = new github.GitHub(accessToken)
+  const params: ReposGetArchiveLinkParams = {
+    owner: owner,
+    repo: repo,
+    archive_format: IS_WINDOWS ? 'zipball' : 'tarball',
+    ref: commit || ref
+  }
+  const response = await octokit.repos.getArchiveLink(params)
+  if (response.status != 200) {
+    throw new Error(
+      `Unexpected response from GitHub API. Status: ${response.status}, Data: ${response.data}`
+    )
+  }
+
+  return Buffer.from(response.data) // response.data is ArrayBuffer
+}