From eb111997f2ae866f4fd3864f0a8a3974f1b48ecc Mon Sep 17 00:00:00 2001
From: Aaron Abramov <aaron@abramov.io>
Date: Tue, 10 Jul 2018 19:10:27 -0700
Subject: [PATCH] fix beforeEach hook execution order

---
 .../__snapshots__/hooks.test.js.snap          | 39 +++++++++++++++++++
 .../jest-circus/src/__tests__/hooks.test.js   | 28 +++++++++++--
 packages/jest-circus/src/utils.js             |  8 ++--
 3 files changed, 69 insertions(+), 6 deletions(-)

diff --git a/packages/jest-circus/src/__tests__/__snapshots__/hooks.test.js.snap b/packages/jest-circus/src/__tests__/__snapshots__/hooks.test.js.snap
index f7deba86c216..1bef73d5a221 100644
--- a/packages/jest-circus/src/__tests__/__snapshots__/hooks.test.js.snap
+++ b/packages/jest-circus/src/__tests__/__snapshots__/hooks.test.js.snap
@@ -23,12 +23,14 @@ run_describe_start: ROOT_DESCRIBE_BLOCK
 run_describe_start: describe
 test_start: one
 hook_start: beforeEach
+> describe beforeEach
 hook_success: beforeEach
 test_fn_start: one
 test_fn_success: one
 test_done: one
 test_start: two
 hook_start: beforeEach
+> describe beforeEach
 hook_success: beforeEach
 test_fn_start: two
 test_fn_success: two
@@ -36,8 +38,10 @@ test_done: two
 run_describe_start: 2nd level describe
 test_start: 2nd level test
 hook_start: beforeEach
+> describe beforeEach
 hook_success: beforeEach
 hook_start: beforeEach
+> 2nd level describe beforeEach
 hook_success: beforeEach
 test_fn_start: 2nd level test
 test_fn_success: 2nd level test
@@ -45,16 +49,20 @@ test_done: 2nd level test
 run_describe_start: 3rd level describe
 test_start: 3rd level test
 hook_start: beforeEach
+> describe beforeEach
 hook_success: beforeEach
 hook_start: beforeEach
+> 2nd level describe beforeEach
 hook_success: beforeEach
 test_fn_start: 3rd level test
 test_fn_success: 3rd level test
 test_done: 3rd level test
 test_start: 3rd level test#2
 hook_start: beforeEach
+> describe beforeEach
 hook_success: beforeEach
 hook_start: beforeEach
+> 2nd level describe beforeEach
 hook_success: beforeEach
 test_fn_start: 3rd level test#2
 test_fn_success: 3rd level test#2
@@ -65,6 +73,7 @@ run_describe_finish: describe
 run_describe_start: 2nd describe
 test_start: 2nd describe test
 hook_start: beforeEach
+> 2nd describe beforeEach that throws
 hook_failure: beforeEach
 test_fn_start: 2nd describe test
 test_done: 2nd describe test
@@ -74,3 +83,33 @@ run_finish
 
 unhandledErrors: 0"
 `;
+
+exports[`multiple before each hooks in one describe are executed in the right order 1`] = `
+"start_describe_definition: describe 1
+add_hook: beforeEach
+add_hook: beforeEach
+start_describe_definition: 2nd level describe
+add_test: test
+finish_describe_definition: 2nd level describe
+finish_describe_definition: describe 1
+run_start
+run_describe_start: ROOT_DESCRIBE_BLOCK
+run_describe_start: describe 1
+run_describe_start: 2nd level describe
+test_start: test
+hook_start: beforeEach
+before each 1
+hook_success: beforeEach
+hook_start: beforeEach
+before each 2
+hook_success: beforeEach
+test_fn_start: test
+test_fn_success: test
+test_done: test
+run_describe_finish: 2nd level describe
+run_describe_finish: describe 1
+run_describe_finish: ROOT_DESCRIBE_BLOCK
+run_finish
+
+unhandledErrors: 0"
+`;
diff --git a/packages/jest-circus/src/__tests__/hooks.test.js b/packages/jest-circus/src/__tests__/hooks.test.js
index c9509bd2ea4e..94c482118e1a 100644
--- a/packages/jest-circus/src/__tests__/hooks.test.js
+++ b/packages/jest-circus/src/__tests__/hooks.test.js
@@ -15,11 +15,11 @@ import {runTest} from '../__mocks__/test_utils';
 test('beforeEach is executed before each test in current/child describe blocks', () => {
   const {stdout} = runTest(`
     describe('describe', () => {
-      beforeEach(() => {});
+      beforeEach(() => console.log('> describe beforeEach'));
       test('one', () => {});
       test('two', () => {});
       describe('2nd level describe', () => {
-        beforeEach(() => {});
+        beforeEach(() => console.log('> 2nd level describe beforeEach'));
         test('2nd level test', () => {});
 
         describe('3rd level describe', () => {
@@ -30,10 +30,32 @@ test('beforeEach is executed before each test in current/child describe blocks',
     })
 
     describe('2nd describe', () => {
-      beforeEach(() => { throw new Error('alabama'); });
+      beforeEach(() => {
+        console.log('> 2nd describe beforeEach that throws')
+        throw new Error('alabama');
+      });
       test('2nd describe test', () => {});
     })
   `);
 
   expect(stdout).toMatchSnapshot();
 });
+
+test('multiple before each hooks in one describe are executed in the right order', () => {
+  const {stdout} = runTest(`
+    describe('describe 1', () => {
+      beforeEach(() => {
+        console.log('before each 1');
+      });
+      beforeEach(() => {
+        console.log('before each 2');
+      });
+
+      describe('2nd level describe', () => {
+        test('test', () => {});
+      });
+    });
+  `);
+
+  expect(stdout).toMatchSnapshot();
+});
diff --git a/packages/jest-circus/src/utils.js b/packages/jest-circus/src/utils.js
index eda159eb7d74..5a606026cdac 100644
--- a/packages/jest-circus/src/utils.js
+++ b/packages/jest-circus/src/utils.js
@@ -130,18 +130,20 @@ export const getEachHooksForTest = (
   let {parent: block} = test;
 
   do {
+    const beforeEachForCurrentBlock = [];
     for (const hook of block.hooks) {
       switch (hook.type) {
         case 'beforeEach':
-          // Before hooks are executed from top to bottom, the opposite of the
-          // way we traversed it.
-          result.beforeEach.unshift(hook);
+          beforeEachForCurrentBlock.push(hook);
           break;
         case 'afterEach':
           result.afterEach.push(hook);
           break;
       }
     }
+    // 'beforeEach' hooks are executed from top to bottom, the opposite of the
+    // way we traversed it.
+    result.beforeEach = [...beforeEachForCurrentBlock, ...result.beforeEach];
   } while ((block = block.parent));
   return result;
 };