fix: disambiguate stash reference (#906)

* Disambiguate stash reference

* Test verifying functionality with branch named stash

* Revert fix to see if this is a real failure

* Disable the test too

* Add back tests

Co-authored-by: Philip Bjorge <philip@philipbjorge.com>

lib/gitWorkflow.js

@@ -100,7 +100,7 @@ class GitWorkflow {
       ctx.errors.add(GetBackupStashError)
       throw new Error('lint-staged automatic backup is missing!')
     }
-    return `stash@{${index}}`
+    return `refs/stash@{${index}}`
   }
 
   /**

test/integration.test.js

@@ -1032,6 +1032,27 @@ describe('lint-staged', () => {
     expect(await execGit(['rev-list', '--count', 'HEAD'])).toEqual('2')
     expect(await readFile('--looks-like-flag.js')).toEqual(testJsFilePretty)
   })
+
+  it('should work when a branch named stash exists', async () => {
+    // create a new branch called stash
+    await execGit(['branch', 'stash'])
+
+    // Stage multiple ugly files
+    await appendFile('test.js', testJsFileUgly)
+    await execGit(['add', 'test.js'])
+
+    await appendFile('test2.js', testJsFileUgly)
+    await execGit(['add', 'test2.js'])
+
+    // Run lint-staged with `prettier --write` and commit pretty file
+    await gitCommit(fixJsConfig)
+
+    // Nothing is wrong, so a new commit is created and file is pretty
+    expect(await execGit(['rev-list', '--count', 'HEAD'])).toEqual('2')
+    expect(await execGit(['log', '-1', '--pretty=%B'])).toMatch('test')
+    expect(await readFile('test.js')).toEqual(testJsFilePretty)
+    expect(await readFile('test2.js')).toEqual(testJsFilePretty)
+  })
 })
 
 describe('lintStaged', () => {