Try cloning without actions/checkout

README.md

@@ -27,17 +27,6 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      # Perform a minimal checkout to set up this repository for the rest of the
-      # workflow.
-      #
-      # This step must be configured exactly as below: using different
-      # actions/checkout arguments is not supported.
-      - name: Checkout this repository
-        uses: actions/checkout@v4
-        with:
-          filter: tree:0
-
-      # Run the estimation tool
       - name: Run sizeup
         # TODO: Replace the version below with your desired version.
         uses: lerebear/[email protected]

__tests__/main.test.ts

@@ -69,6 +69,9 @@ describe('action', () => {
   // Shallow clone original @actions/github context
   const originalContext = { ...github.context }
 
+  // Mock cloning the repo
+  jest.spyOn(initializer, 'clone').mockImplementation(async () => {})
+
   // Mock the diff that we use for evaluation.
   jest
     .spyOn(initializer, 'fetchDiff')

src/initializer.ts

@@ -60,6 +60,20 @@ export function pullRequestAuthorHasNotOptedIn(
   return false
 }
 
+export async function clone(pull: PullRequest): Promise<void> {
+  const git = simpleGit('.', { trimmed: true })
+  const repo = `${github.context.repo.owner}/${github.context.repo.repo}`
+
+  core.info(`Cloning ${repo} with the single branch "${pull.head.ref}"`)
+
+  await git.clone(`https://${core.getInput('token')}@github.com/${repo}`, '.', [
+    `--branch=${pull.head.ref}`,
+    '--filter=tree:0',
+    '--no-tags',
+    '--single-branch'
+  ])
+}
+
 /**
  * Retrieves the diff of the pull request that triggered this workflow which we
  * will use for evaluation.
@@ -72,42 +86,16 @@ export async function fetchDiff(
 ): Promise<string | undefined> {
   const git = simpleGit('.', { trimmed: true })
 
-  // let baseRefExists = false
-  // try {
-  //   baseRefExists = !!(await git.raw('rev-parse', '--verify', pull.base.ref))
-  // } catch (e) {
-  //   core.error(
-  //     `Error from 'git rev-parse --verfy ${pull.base.ref}': ${
-  //       (e as Error).message
-  //     }`
-  //   )
-  // }
-
-  // if (!baseRefExists) {
-  //   core.setFailed(
-  //     `Could not find pull request base branch ${pull.base.ref}. ` +
-  //       `Please make sure actions/checkout was used beforehand to fetch ${pull.base.ref}.`
-  //   )
-  //   return
-  // }
-
-  core.debug(
-    `Fetching base ref "${pull.base.ref}" and head ref "${pull.head.ref}"`
-  )
-
+  core.debug(`Fetching base ref "${pull.base.ref}"`)
   await git.fetch([
     'origin',
     `+${pull.base.ref}:${pull.base.ref}`,
-    `+${pull.head.ref}:${pull.head.ref}`,
     `--filter=tree:0`,
     '--no-tags',
     '--prune',
     '--no-recurse-submodules'
   ])
 
-  core.debug(`Switching to head ref "${pull.head.ref}"`)
-  await git.raw('switch', pull.head.ref)
-
   const diffArgs = ['--merge-base', pull.base.ref].concat(
     core.getInput('git-diff-options').split(/\s+/)
   )

src/main.ts

@@ -7,6 +7,7 @@ import * as fs from 'fs'
 import * as path from 'path'
 import { Configuration } from './configuration'
 import {
+  clone,
   fetchDiff,
   loadConfiguration,
   pullRequestAuthorHasNotOptedIn,
@@ -32,8 +33,9 @@ export async function run(): Promise<void> {
   try {
     if (workflowTriggeredForUnsupportedEvent()) return
 
-    const config = loadConfiguration()
     const pullRequest = github.context.payload.pull_request as PullRequest
+    await clone(pullRequest)
+    const config = loadConfiguration()
 
     if (pullRequestAuthorHasNotOptedIn(config, pullRequest)) return