add separate clone script to be run as heroku-prebuild script or locally by docs writers

package.json

@@ -140,7 +140,7 @@
     "prevent-pushes-to-main": "node script/prevent-pushes-to-main.js",
     "pa11y-ci": "pa11y-ci",
     "pa11y-test": "start-server-and-test browser-test-server 4001 pa11y-ci",
-    "heroku-prebuild": "rm -rf content/early-access-test && git clone https://${TEMP_KEY_ACCESS_KEY}@github.com/docs/early-access-test content/early-access-test && rm -rf content/early-access-test/.git"
+    "heroku-prebuild": "node script/clone-early-access.js"
   },
   "engines": {
     "node": "12 - 14"

script/clone-early-access.js

@@ -0,0 +1,57 @@
+#!/usr/bin/env node
+
+// [start-readme]
+//
+// This script is run as a prebuild script during staging and deployments on Heroku.
+// If you have access to the PAT, it can also be run locally to clone https://github.com/docs/early-access.
+// The script clones a branch in the early-access repo that matches the current branch in the docs repo;
+// if one can't be found, it clones the `main` branch.
+//
+// [end-readme]
+
+require('dotenv').config()
+const { GITHUB_DOCUBOT_REPO_PAT } = process.env
+
+// TODO...
+// // Exit if early access is not enabled
+// if (!process.env.EARLY_ACCESS_ENABLED) {
+//   console.log('Skipping early access, not enable')
+//   process.exit(0)
+// }
+
+// Exit if PAT is not found
+if (!process.env.GITHUB_DOCUBOT_REPO_PAT) {
+  console.log('Skipping early access, not authorized')
+  process.exit(0)
+}
+
+const { execSync } = require('child_process')
+const rimraf = require('rimraf').sync
+const fs = require('fs')
+const path = require('path')
+
+// Early Access details
+const earlyAccessDir = 'early-access-test'
+const earlyAccessRepo = `https://${GITHUB_DOCUBOT_REPO_PAT}@github.com/docs/${earlyAccessDir}`
+const earlyAccessContentDir = path.join(process.cwd(), 'content', earlyAccessDir)
+
+// Look for a branch in early-access that matches the current docs branch;
+// otherwise fall back to `main`
+const docsBranch = execSync('git branch --show-current').toString().trim()
+
+const earlyAccessBranch = execSync(`git ls-remote --heads ${earlyAccessRepo} ${docsBranch}`).toString()
+  ? docsBranch
+  : 'main'
+
+// Remove any dir that may pre-exist
+rimraf(earlyAccessContentDir)
+
+// Clone the repo
+execSync(`git clone --single-branch --branch ${earlyAccessBranch} ${earlyAccessRepo} ${earlyAccessContentDir}`)
+console.log(`Branch: ${earlyAccessBranch}`)
+
+// Remove the .git dir
+rimraf(`${earlyAccessContentDir}/.git`)
+
+// Confirm the directory exists
+fs.existsSync(earlyAccessContentDir)