fix: support binary files

lib/gitWorkflow.js

@@ -71,7 +71,7 @@ class GitWorkflow {
     // Get diff of staged modifications. This will be applied back to the index. after stashing all changes.
     // The `git stash save --keep-index` option cannot be used since it resurrects deleted files on
     // git versions before v2.23.0 (https://github.com/git/git/blob/master/Documentation/RelNotes/2.23.0.txt#L322)
-    const stagedDiff = await this.execGit(['diff', '--cached'])
+    const stagedDiff = await this.execGit(['diff', '--binary', '--cached'])
 
     // Save stash of entire original state, including unstaged and untracked changes.
     // This should remove all changes from the index.
@@ -82,6 +82,7 @@ class GitWorkflow {
 
     this.unstagedDiff = await this.execGit([
       'diff',
+      '--binary',
       '--unified=0',
       '--no-color',
       '--no-ext-diff',

test/runAll.unmocked.spec.js

@@ -516,4 +516,21 @@ describe('runAll', () => {
     const exists = await fs.exists(readmeFile)
     expect(exists).toEqual(false)
   })
+
+  it('should handle binary files', async () => {
+    // mark test.js as binary file
+    await appendFile('.gitattributes', 'test.js binary\n')
+
+    // Stage pretty file
+    await appendFile('test.js', testJsFilePretty)
+    await execGit(['add', 'test.js'])
+
+    // Run lint-staged with `prettier --list-different` and commit pretty file
+    await gitCommit({ config: { '*.js': 'prettier --list-different' } })
+
+    // Nothing is wrong, so a new commit is created
+    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)
+  })
 })