Strip trailing tab from parsed paths with spaces

CONTRIBUTING.md

@@ -20,7 +20,7 @@ Local development and CI share these entrypoints. The `npm run` aliases remain a
 - `script/all` runs lint, unit tests, build, and acceptance.
 - `script/verify-bundle` rebuilds and rejects tracked or untracked changes in `dist/`. Run it after committing the generated files.
 
-Keep inputs, outputs, defaults, errors, and diff parsing compatible. The parser currently truncates some `--binary` diffs and retains a trailing tab for some paths containing spaces. Tests preserve these existing behaviors. Parser fixes should be separate, deliberate changes.
+Keep inputs, outputs, defaults, errors, and diff parsing compatible. The parser currently truncates some `--binary` diffs. Tests preserve this existing behavior. Parser fixes should be separate, deliberate changes.
 
 The only runtime package is `parse-git-diff`. TypeScript provides type checking, `@types/node` describes the supported runtime, Prettier provides formatting, and `ncc` produces the self-contained Action. The local Actions adapter implements only the string input/output and logging functions this repository uses. Its toolkit attribution is in `LICENSES/actions-toolkit.txt` and the generated distribution notices.
 

__tests__/acceptance.test.ts

@@ -146,8 +146,7 @@ test('standalone bundle runs real Git with spaces in path and file-only outputs'
     const parsed: {files: Array<{path: string}>} = JSON.parse(
       readFileSync(join(action.workspace, 'diff.json'), 'utf8')
     )
-    // Preserve parse-git-diff's existing trailing-tab behavior for spaced paths.
-    assert.equal(parsed.files[0]?.path, 'space name.txt\t')
+    assert.equal(parsed.files[0]?.path, 'space name.txt')
     assert.match(
       readFileSync(join(action.workspace, 'raw.txt'), 'utf8'),
       /after 雪/

__tests__/fixtures/paths-with-spaces.diff

@@ -0,0 +1,34 @@
+diff --git a/added file.txt b/added file.txt
+new file mode 100644
+index 0000000000000000000000000000000000000000..45b983be36b73c0788dc9cbcb76cbb80fc7bb057
+--- /dev/null
++++ b/added file.txt	
+@@ -0,0 +1 @@
++hi
+diff --git a/changed file.txt b/changed file.txt
+index 814f4a422927b82f5f8a43f8fab6d3839e3983f2..4cb29ea38f70d7c61b2a3a25b02e3bdf44905402 100644
+--- a/changed file.txt	
++++ b/changed file.txt	
+@@ -1,2 +1,3 @@
+ one
+ two
++three
+diff --git a/deleted file.txt b/deleted file.txt
+deleted file mode 100644
+index b023018cabc396e7692c70bbf5784a93d3f738ab..0000000000000000000000000000000000000000
+--- a/deleted file.txt	
++++ /dev/null
+@@ -1 +0,0 @@
+-bye
+diff --git a/old name.txt b/new name.txt
+similarity index 85%
+rename from old name.txt
+rename to new name.txt
+index 0fdf397db08b5cecda1b6394d4fef7395c1933ba..f9d9a0195c5b9c01ef64e2a69d8b9a624f42b8c8 100644
+--- a/old name.txt	
++++ b/new name.txt	
+@@ -4,3 +4,4 @@ c
+ d
+ e
+ f
++g

__tests__/git-diff.test.ts

@@ -106,6 +106,22 @@ for (const [file, count, rawCount] of [
   })
 }
 
+test('strips the trailing tab git adds to paths with spaces', async () => {
+  process.env.INPUT_GIT_DIFF_FILE = '__tests__/fixtures/paths-with-spaces.diff'
+  const result = await gitDiff()
+  assert.deepEqual(
+    result?.files.map(file =>
+      'path' in file ? file.path : [file.pathBefore, file.pathAfter]
+    ),
+    [
+      'added file.txt',
+      'changed file.txt',
+      'deleted file.txt',
+      ['old name.txt', 'new name.txt']
+    ]
+  )
+})
+
 for (const [value, expected] of [
   ['', []],
   ['   ', []],

src/functions/git-diff.ts

@@ -1,5 +1,5 @@
 import * as core from '../actions-core.ts'
-import parseGitDiff from 'parse-git-diff'
+import parseGitDiff, {type GitDiff} from 'parse-git-diff'
 import {execFileAsync} from './exec-async.ts'
 import fs from 'node:fs'
 import path from 'node:path'
@@ -137,6 +137,17 @@ function resolveWorkspacePath(filePath: string) {
   )
 }
 
+// git appends a tab to `---` and `+++` paths that contain spaces, and
+// parse-git-diff keeps that tab in the parsed path
+function stripPathTrailingTabs(diff: GitDiff) {
+  for (const file of diff.files) {
+    if ('path' in file && file.path.endsWith('\t')) {
+      file.path = file.path.slice(0, -1)
+    }
+  }
+  return diff
+}
+
 // Helper function to get the diff from the git command
 // :returns: The diff object which is parsed git diff
 // If an error occurs, setFailed is called and it returns null
@@ -214,7 +225,7 @@ export async function gitDiff() {
     }
 
     // JSON diff
-    const diff = parseGitDiff(rawGitDiff)
+    const diff = stripPathTrailingTabs(parseGitDiff(rawGitDiff))
     const jsonDiff = JSON.stringify(diff)
 
     // log the total amount of files changed in the json diff