From 0924baf19541a03fd37cdb0a2bf13486b397483a Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Sun, 12 Apr 2020 17:46:03 +0200
Subject: [PATCH] fix: `--only-changed` should include staged files (#9799)

---
 CHANGELOG.md                           |  1 +
 e2e/__tests__/jestChangedFiles.test.ts | 16 ++++++--
 packages/jest-changed-files/src/git.ts | 57 +++++++++++++++-----------
 3 files changed, 47 insertions(+), 27 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fa2445e8f8b4..0c5588c37208 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Fixes
 
 - `[expect]` Restore support for passing functions to `toHaveLength` matcher ([#9796](https://github.com/facebook/jest/pull/9796))
+- `[jest-changed-files]` `--only-changed` should include staged files ([#9799](https://github.com/facebook/jest/pull/9799))
 
 ### Chore & Maintenance
 
diff --git a/e2e/__tests__/jestChangedFiles.test.ts b/e2e/__tests__/jestChangedFiles.test.ts
index 66bcb05ff395..5b8e3014cd7b 100644
--- a/e2e/__tests__/jestChangedFiles.test.ts
+++ b/e2e/__tests__/jestChangedFiles.test.ts
@@ -32,7 +32,7 @@ if (!hgIsInstalled) {
   console.warn('Mercurial (hg) is not installed - skipping some tests');
 }
 
-testIfHg('gets hg SCM roots and dedups them', async () => {
+testIfHg('gets hg SCM roots and dedupes them', async () => {
   writeFiles(DIR, {
     'first-repo/file1.txt': 'file1',
     'first-repo/nested-dir/file2.txt': 'file2',
@@ -67,7 +67,7 @@ testIfHg('gets hg SCM roots and dedups them', async () => {
   expect(hgRepos[1]).toMatch(/\/jest-changed-files-test-dir\/second-repo\/?$/);
 });
 
-test('gets git SCM roots and dedups them', async () => {
+test('gets git SCM roots and dedupes them', async () => {
   writeFiles(DIR, {
     'first-repo/file1.txt': 'file1',
     'first-repo/nested-dir/file2.txt': 'file2',
@@ -101,7 +101,7 @@ test('gets git SCM roots and dedups them', async () => {
   expect(gitRepos[1]).toMatch(/\/jest-changed-files-test-dir\/second-repo\/?$/);
 });
 
-testIfHg('gets mixed git and hg SCM roots and dedups them', async () => {
+testIfHg('gets mixed git and hg SCM roots and dedupes them', async () => {
   writeFiles(DIR, {
     'first-repo/file1.txt': 'file1',
     'first-repo/nested-dir/file2.txt': 'file2',
@@ -186,6 +186,16 @@ test('gets changed files for git', async () => {
       .sort(),
   ).toEqual(['file1.txt']);
 
+  run(`${GIT} add -A`, DIR);
+
+  // staged files should be included
+  ({changedFiles: files} = await getChangedFilesForRoots(roots, {}));
+  expect(
+    Array.from(files)
+      .map(filePath => path.basename(filePath))
+      .sort(),
+  ).toEqual(['file1.txt']);
+
   run(`${GIT} commit --no-gpg-sign -am "test2"`, DIR);
 
   writeFiles(DIR, {
diff --git a/packages/jest-changed-files/src/git.ts b/packages/jest-changed-files/src/git.ts
index 70ab9ced6cec..919eb19be98d 100644
--- a/packages/jest-changed-files/src/git.ts
+++ b/packages/jest-changed-files/src/git.ts
@@ -50,36 +50,45 @@ const adapter: SCMAdapter = {
         ),
         cwd,
       );
-    } else if (changedSince) {
-      const committed = await findChangedFilesUsingCommand(
-        [
-          'log',
-          '--name-only',
-          '--pretty=format:',
-          'HEAD',
-          `^${changedSince}`,
-        ].concat(includePaths),
-        cwd,
-      );
-      const staged = await findChangedFilesUsingCommand(
-        ['diff', '--cached', '--name-only'].concat(includePaths),
-        cwd,
-      );
-      const unstaged = await findChangedFilesUsingCommand(
-        ['ls-files', '--other', '--modified', '--exclude-standard'].concat(
-          includePaths,
+    }
+    if (changedSince) {
+      const [committed, staged, unstaged] = await Promise.all([
+        findChangedFilesUsingCommand(
+          [
+            'log',
+            '--name-only',
+            '--pretty=format:',
+            'HEAD',
+            `^${changedSince}`,
+          ].concat(includePaths),
+          cwd,
         ),
-        cwd,
-      );
+        findChangedFilesUsingCommand(
+          ['diff', '--cached', '--name-only'].concat(includePaths),
+          cwd,
+        ),
+        findChangedFilesUsingCommand(
+          ['ls-files', '--other', '--modified', '--exclude-standard'].concat(
+            includePaths,
+          ),
+          cwd,
+        ),
+      ]);
       return [...committed, ...staged, ...unstaged];
-    } else {
-      return findChangedFilesUsingCommand(
+    }
+    const [staged, unstaged] = await Promise.all([
+      findChangedFilesUsingCommand(
+        ['diff', '--cached', '--name-only'].concat(includePaths),
+        cwd,
+      ),
+      findChangedFilesUsingCommand(
         ['ls-files', '--other', '--modified', '--exclude-standard'].concat(
           includePaths,
         ),
         cwd,
-      );
-    }
+      ),
+    ]);
+    return [...staged, ...unstaged];
   },
 
   getRoot: async cwd => {