feat: add unique hash to backup stash message

.changeset/soft-ties-poke.md

@@ -0,0 +1,5 @@
+---
+'lint-staged': minor
+---
+
+Add unique hash to each backup stash message; this refers to the dangling commit created with "git stash create"

README.md

@@ -13,7 +13,7 @@ npm install --save-dev lint-staged # requires further setup
 ```
 $ git commit
 
-✔ Backed up original state in git stash
+✔ Backed up original state in git stash (5bda95f)
 ❯ Running tasks for staged files...
   ❯ packages/frontend/.lintstagedrc.json — 1 file
     ↓ *.js — no files [SKIPPED]

lib/gitWorkflow.js

@@ -98,7 +98,11 @@ export class GitWorkflow {
    */
   async getBackupStash(ctx) {
     const stashes = await this.execGit(['stash', 'list'])
-    const index = stashes.split('\n').findIndex((line) => line.includes(STASH))
+
+    const index = stashes
+      .split('\n')
+      .findIndex((line) => line.includes(STASH) && line.includes(ctx.backupHash))
+
     if (index === -1) {
       ctx.errors.add(GetBackupStashError)
       throw new Error('lint-staged automatic backup is missing!')
@@ -223,11 +227,19 @@ export class GitWorkflow {
       // Save stash of all staged files.
       // The `stash create` command creates a dangling commit without removing any files,
       // and `stash store` saves it as an actual stash.
-      const hash = await this.execGit(['stash', 'create'])
-      await this.execGit(['stash', 'store', '--quiet', '--message', STASH, hash])
+      const stashHash = await this.execGit(['stash', 'create'])
+      ctx.backupHash = await this.execGit(['rev-parse', '--short', stashHash])
+      await this.execGit([
+        'stash',
+        'store',
+        '--quiet',
+        '--message',
+        `${STASH} (${ctx.backupHash})`,
+        ctx.backupHash,
+      ])
 
-      debugLog('Done backing up original state in "git stash"!')
-      task.title = 'Backed up original state in git stash'
+      task.title = `Backed up original state in git stash (${ctx.backupHash})`
+      debugLog(task.title)
     } catch (error) {
       handleError(error, ctx)
     }

lib/state.js

@@ -12,6 +12,7 @@ import {
 export const getInitialState = ({ quiet = false } = {}) => ({
   hasPartiallyStagedFiles: null,
   shouldBackup: null,
+  backupHash: null,
   shouldHidePartiallyStaged: true,
   errors: new Set([]),
   events: new EventEmitter(),

test/integration/git-lock-file.test.js

@@ -64,9 +64,7 @@ describe('lint-staged', () => {
       await removeFile(`.git/index.lock`)
 
       // Luckily there is a stash
-      expect(await execGit(['stash', 'list'])).toMatchInlineSnapshot(
-        `"stash@{0}: lint-staged automatic backup"`
-      )
+      expect(await execGit(['stash', 'list'])).toMatch('stash@{0}: lint-staged automatic backup')
       await execGit(['reset', '--hard'])
       await execGit(['stash', 'pop', '--index'])
 

test/unit/getBackupStash.spec.js

@@ -31,8 +31,9 @@ describe('gitWorkflow', () => {
     it('should throw when stash not found even when other stashes are', async () => {
       const gitWorkflow = new GitWorkflow(options)
       const ctx = getInitialState()
+      ctx.backupHash = 'not-found'
 
-      execGit.mockResolvedValueOnce('stash@{0}: some random stuff')
+      execGit.mockResolvedValueOnce(`stash@{1}: ${STASH} (abc123)`)
 
       await expect(gitWorkflow.getBackupStash(ctx)).rejects.toThrow(
         'lint-staged automatic backup is missing!'
@@ -44,11 +45,12 @@ describe('gitWorkflow', () => {
     it('should return ref to the backup stash', async () => {
       const gitWorkflow = new GitWorkflow(options)
       const ctx = getInitialState()
+      ctx.backupHash = 'abc123'
 
       execGit.mockResolvedValueOnce(
         [
           'stash@{0}: some random stuff',
-          `stash@{1}: ${STASH}`,
+          `stash@{1}: ${STASH} (${ctx.backupHash})`,
           'stash@{2}: other random stuff',
         ].join('\n')
       )