fix: use showFileAtRefBase64 to read per-commit file contents (#3744)

* GitCommandManager: add a function to get a file's contents at a specific revision

* use showFileAtRef instead of readFileBase64

* Teach GitCommandManager.exec about an object of exec parameters so we can add more

* Encode the showFiletRef output as base64 out of the gate

* Fix missing async for function

* Use Buffer.concat to avoid issues with partial data streams

* formatting

---------

Co-authored-by: gustavderdrache <alex.ford@determinate.systems>

src/create-or-update-branch.ts

@@ -19,7 +19,7 @@ export async function getWorkingBaseAndType(
 ): Promise<[string, WorkingBaseType]> {
   const symbolicRefResult = await git.exec(
     ['symbolic-ref', 'HEAD', '--short'],
-    true
+    {allowAllExitCodes: true}
   )
   if (symbolicRefResult.exitCode == 0) {
     // A ref is checked out
@@ -200,7 +200,7 @@ export async function createOrUpdateBranch(
     } else {
       aopts.push('-A')
     }
-    await git.exec(aopts, true)
+    await git.exec(aopts, {allowAllExitCodes: true})
     const popts = ['-m', commitMessage]
     if (signoff) {
       popts.push('--signoff')

src/create-pull-request.ts

@@ -211,6 +211,7 @@ export async function createPullRequest(inputs: Inputs): Promise<void> {
         const stashed = await git.stashPush(['--include-untracked'])
         await git.checkout(inputs.branch)
         const pushSignedCommitsResult = await ghBranch.pushSignedCommits(
+          git,
           result.branchCommits,
           result.baseCommit,
           repoPath,

src/git-command-manager.ts

@@ -21,6 +21,11 @@ export type Commit = {
   unparsedChanges: string[]
 }
 
+export type ExecOpts = {
+  allowAllExitCodes?: boolean
+  encoding?: 'utf8' | 'base64'
+}
+
 export class GitCommandManager {
   private gitPath: string
   private workingDirectory: string
@@ -66,7 +71,7 @@ export class GitCommandManager {
       args.push(...options)
     }
 
-    return await this.exec(args, allowAllExitCodes)
+    return await this.exec(args, {allowAllExitCodes: allowAllExitCodes})
   }
 
   async commit(
@@ -82,7 +87,7 @@ export class GitCommandManager {
       args.push(...options)
     }
 
-    return await this.exec(args, allowAllExitCodes)
+    return await this.exec(args, {allowAllExitCodes: allowAllExitCodes})
   }
 
   async config(
@@ -113,7 +118,7 @@ export class GitCommandManager {
         configKey,
         configValue
       ],
-      true
+      {allowAllExitCodes: true}
     )
     return output.exitCode === 0
   }
@@ -222,7 +227,7 @@ export class GitCommandManager {
     if (options) {
       args.push(...options)
     }
-    const output = await this.exec(args, true)
+    const output = await this.exec(args, {allowAllExitCodes: true})
     return output.exitCode === 1
   }
 
@@ -278,6 +283,12 @@ export class GitCommandManager {
     return output.stdout.trim()
   }
 
+  async showFileAtRefBase64(ref: string, path: string): Promise<string> {
+    const args = ['show', `${ref}:${path}`]
+    const output = await this.exec(args, {encoding: 'base64'})
+    return output.stdout.trim()
+  }
+
   async stashPush(options?: string[]): Promise<boolean> {
     const args = ['stash', 'push']
     if (options) {
@@ -326,7 +337,7 @@ export class GitCommandManager {
         configKey,
         configValue
       ],
-      true
+      {allowAllExitCodes: true}
     )
     return output.exitCode === 0
   }
@@ -334,7 +345,7 @@ export class GitCommandManager {
   async tryGetRemoteUrl(): Promise<string> {
     const output = await this.exec(
       ['config', '--local', '--get', 'remote.origin.url'],
-      true
+      {allowAllExitCodes: true}
     )
 
     if (output.exitCode !== 0) {
@@ -349,7 +360,10 @@ export class GitCommandManager {
     return stdout
   }
 
-  async exec(args: string[], allowAllExitCodes = false): Promise<GitOutput> {
+  async exec(
+    args: string[],
+    {encoding = 'utf8', allowAllExitCodes = false}: ExecOpts = {}
+  ): Promise<GitOutput> {
     const result = new GitOutput()
 
     const env = {}
@@ -357,8 +371,10 @@ export class GitCommandManager {
       env[key] = process.env[key]
     }
 
-    const stdout: string[] = []
-    const stderr: string[] = []
+    const stdout: Buffer[] = []
+    let stdoutLength = 0
+    const stderr: Buffer[] = []
+    let stderrLength = 0
 
     const options = {
       cwd: this.workingDirectory,
@@ -366,17 +382,19 @@ export class GitCommandManager {
       ignoreReturnCode: allowAllExitCodes,
       listeners: {
         stdout: (data: Buffer) => {
-          stdout.push(data.toString())
+          stdout.push(data)
+          stdoutLength += data.length
         },
         stderr: (data: Buffer) => {
-          stderr.push(data.toString())
+          stderr.push(data)
+          stderrLength += data.length
         }
       }
     }
 
     result.exitCode = await exec.exec(`"${this.gitPath}"`, args, options)
-    result.stdout = stdout.join('')
-    result.stderr = stderr.join('')
+    result.stdout = Buffer.concat(stdout, stdoutLength).toString(encoding)
+    result.stderr = Buffer.concat(stderr, stderrLength).toString(encoding)
     return result
   }
 }

src/github-helper.ts

@@ -1,6 +1,6 @@
 import * as core from '@actions/core'
 import {Inputs} from './create-pull-request'
-import {Commit} from './git-command-manager'
+import {Commit, GitCommandManager} from './git-command-manager'
 import {Octokit, OctokitOptions, throttleOptions} from './octokit-client'
 import pLimit from 'p-limit'
 import * as utils from './utils'
@@ -220,6 +220,7 @@ export class GitHubHelper {
   }
 
   async pushSignedCommits(
+    git: GitCommandManager,
     branchCommits: Commit[],
     baseCommit: Commit,
     repoPath: string,
@@ -233,6 +234,7 @@ export class GitHubHelper {
     }
     for (const commit of branchCommits) {
       headCommit = await this.createCommit(
+        git,
         commit,
         headCommit,
         repoPath,
@@ -244,6 +246,7 @@ export class GitHubHelper {
   }
 
   private async createCommit(
+    git: GitCommandManager,
     commit: Commit,
     parentCommit: CommitResponse,
     repoPath: string,
@@ -269,10 +272,10 @@ export class GitHubHelper {
             let sha: string | null = null
             if (status === 'A' || status === 'M') {
               try {
-                const {data: blob} = await blobCreationLimit(() =>
+                const {data: blob} = await blobCreationLimit(async () =>
                   this.octokit.rest.git.createBlob({
                     ...repository,
-                    content: utils.readFileBase64([repoPath, path]),
+                    content: await git.showFileAtRefBase64(commit.sha, path),
                     encoding: 'base64'
                   })
                 )

src/utils.ts

@@ -126,16 +126,6 @@ export function readFile(path: string): string {
   return fs.readFileSync(path, 'utf-8')
 }
 
-export function readFileBase64(pathParts: string[]): string {
-  const resolvedPath = path.resolve(...pathParts)
-  if (fs.lstatSync(resolvedPath).isSymbolicLink()) {
-    return fs
-      .readlinkSync(resolvedPath, {encoding: 'buffer'})
-      .toString('base64')
-  }
-  return fs.readFileSync(resolvedPath).toString('base64')
-}
-
 /* eslint-disable  @typescript-eslint/no-explicit-any */
 function hasErrorCode(error: any): error is {code: string} {
   return typeof (error && error.code) === 'string'