feat(jest-message-util): render codeframe on failure

Author: SimenB

CHANGELOG.md

@@ -69,6 +69,8 @@
 
 ### Features
 
+* `[jest-message-util]` Add codeframe to test assertion failures
+  ([#5087](https://github.com/facebook/jest/pull/5087))
 * `[jest-config]` Add Global Setup/Teardown options
   ([#4716](https://github.com/facebook/jest/pull/4716))
 * `[jest-config]` Add `testEnvironmentOptions` to apply to jsdom options or node

docs/Configuration.md

@@ -262,14 +262,18 @@ here, and some code mutates that value in the midst of running a test, that
 mutation will _not_ be persisted across test runs for other test files.
 
 ### `globalSetup` [string]
+
 Default: `undefined`
 
-This option allows the use of a custom global setup module which exports an async function that is triggered once before all test suites.
+This option allows the use of a custom global setup module which exports an
+async function that is triggered once before all test suites.
 
 ### `globalTeardown` [string]
+
 Default: `undefined`
 
-This option allows the use of a custom global teardown module which exports an async function that is triggered once after all test suites.
+This option allows the use of a custom global teardown module which exports an
+async function that is triggered once after all test suites.
 
 ### `mapCoverage` [boolean]
 

docs/TimerMocks.md

@@ -34,7 +34,7 @@ test('waits 1 second before ending the game', () => {
   const timerGame = require('../timerGame');
   timerGame();
 
-  expect(setTimeout).toHaveBeenCalledTimes(1)
+  expect(setTimeout).toHaveBeenCalledTimes(1);
   expect(setTimeout).toHaveBeenLastCalledWith(expect.any(Function), 1000);
 });
 ```
@@ -63,7 +63,7 @@ test('calls the callback after 1 second', () => {
 
   // Now our callback should have been called!
   expect(callback).toBeCalled();
-  expect(callback).toHaveBeenCalledTimes(1)
+  expect(callback).toHaveBeenCalledTimes(1);
 });
 ```
 
@@ -110,7 +110,7 @@ describe('infiniteTimerGame', () => {
 
     // At this point in time, there should have been a single call to
     // setTimeout to schedule the end of the game in 1 second.
-    expect(setTimeout).toHaveBeenCalledTimes(1)
+    expect(setTimeout).toHaveBeenCalledTimes(1);
     expect(setTimeout).toHaveBeenLastCalledWith(expect.any(Function), 1000);
 
     // Fast forward and exhaust only currently pending timers
@@ -122,7 +122,7 @@ describe('infiniteTimerGame', () => {
 
     // And it should have created a new timer to start the game over in
     // 10 seconds
-    expect(setTimeout).toHaveBeenCalledTimes(2)
+    expect(setTimeout).toHaveBeenCalledTimes(2);
     expect(setTimeout).toHaveBeenLastCalledWith(expect.any(Function), 10000);
   });
 });
@@ -170,7 +170,7 @@ it('calls the callback after 1 second via advanceTimersByTime', () => {
 
   // Now our callback should have been called!
   expect(callback).toBeCalled();
-  expect(callback).toHaveBeenCalledTimes(1)
+  expect(callback).toHaveBeenCalledTimes(1);
 });
 ```
 

integration_tests/__tests__/__snapshots__/failures.test.js.snap

@@ -40,6 +40,12 @@ exports[`not throwing Error objects 4`] = `
     expect(received).toBeTruthy()
     Expected value to be truthy, instead received
       false
+      11 | const throws = () => {
+      12 |   expect.assertions(2);
+    > 13 |   expect(false).toBeTruthy();
+      14 | };
+      15 | const redeclare = () => {
+      16 |   expect.assertions(1);
       at __tests__/assertion_count.test.js:13:17
   ● .assertions() › throws
     expect.assertions(2)
@@ -48,6 +54,12 @@ exports[`not throwing Error objects 4`] = `
     expect(received).toBeTruthy()
     Expected value to be truthy, instead received
       false
+      15 | const redeclare = () => {
+      16 |   expect.assertions(1);
+    > 17 |   expect(false).toBeTruthy();
+      18 |   expect.assertions(2);
+      19 | };
+      20 |
       at __tests__/assertion_count.test.js:17:17
   ● .assertions() › throws on assertion
     expect.assertions(0)
@@ -85,6 +97,13 @@ exports[`works with node assert 1`] = `
       true
     Received:
       false
+
+      13 | 
+      14 | test('assert', () => {
+    > 15 |   assert(false);
+      16 | });
+      17 | 
+      18 | test('assert with a message', () => {
       
       at __tests__/node_assertion_error.test.js:15:3
 
@@ -99,6 +118,13 @@ exports[`works with node assert 1`] = `
     
     Message:
       this is a message
+
+      17 | 
+      18 | test('assert with a message', () => {
+    > 19 |   assert(false, 'this is a message');
+      20 | });
+      21 | 
+      22 | test('assert.ok', () => {
       
       at __tests__/node_assertion_error.test.js:19:3
 
@@ -110,6 +136,13 @@ exports[`works with node assert 1`] = `
       true
     Received:
       false
+
+      21 | 
+      22 | test('assert.ok', () => {
+    > 23 |   assert.ok(false);
+      24 | });
+      25 | 
+      26 | test('assert.ok with a message', () => {
       
       at __tests__/node_assertion_error.test.js:23:10
 
@@ -124,6 +157,13 @@ exports[`works with node assert 1`] = `
     
     Message:
       this is a message
+
+      25 | 
+      26 | test('assert.ok with a message', () => {
+    > 27 |   assert.ok(false, 'this is a message');
+      28 | });
+      29 | 
+      30 | test('assert.equal', () => {
       
       at __tests__/node_assertion_error.test.js:27:10
 
@@ -135,6 +175,13 @@ exports[`works with node assert 1`] = `
       2
     Received:
       1
+
+      29 | 
+      30 | test('assert.equal', () => {
+    > 31 |   assert.equal(1, 2);
+      32 | });
+      33 | 
+      34 | test('assert.notEqual', () => {
       
       at __tests__/node_assertion_error.test.js:31:10
 
@@ -150,6 +197,13 @@ exports[`works with node assert 1`] = `
     Difference:
     
     Compared values have no visual difference.
+
+      33 | 
+      34 | test('assert.notEqual', () => {
+    > 35 |   assert.notEqual(1, 1);
+      36 | });
+      37 | 
+      38 | test('assert.deepEqual', () => {
       
       at __tests__/node_assertion_error.test.js:35:10
 
@@ -175,6 +229,13 @@ exports[`works with node assert 1`] = `
           },
         },
       }
+
+      37 | 
+      38 | test('assert.deepEqual', () => {
+    > 39 |   assert.deepEqual({a: {b: {c: 5}}}, {a: {b: {c: 6}}});
+      40 | });
+      41 | 
+      42 | test('assert.deepEqual with a message', () => {
       
       at __tests__/node_assertion_error.test.js:39:10
 
@@ -203,6 +264,13 @@ exports[`works with node assert 1`] = `
           },
         },
       }
+
+      41 | 
+      42 | test('assert.deepEqual with a message', () => {
+    > 43 |   assert.deepEqual({a: {b: {c: 5}}}, {a: {b: {c: 7}}}, 'this is a message');
+      44 | });
+      45 | 
+      46 | test('assert.notDeepEqual', () => {
       
       at __tests__/node_assertion_error.test.js:43:10
 
@@ -218,6 +286,13 @@ exports[`works with node assert 1`] = `
     Difference:
     
     Compared values have no visual difference.
+
+      45 | 
+      46 | test('assert.notDeepEqual', () => {
+    > 47 |   assert.notDeepEqual({a: 1}, {a: 1});
+      48 | });
+      49 | 
+      50 | test('assert.strictEqual', () => {
       
       at __tests__/node_assertion_error.test.js:47:10
 
@@ -229,6 +304,13 @@ exports[`works with node assert 1`] = `
       NaN
     Received:
       1
+
+      49 | 
+      50 | test('assert.strictEqual', () => {
+    > 51 |   assert.strictEqual(1, NaN);
+      52 | });
+      53 | 
+      54 | test('assert.notStrictEqual', () => {
       
       at __tests__/node_assertion_error.test.js:51:10
 
@@ -247,6 +329,13 @@ exports[`works with node assert 1`] = `
     Difference:
     
     Compared values have no visual difference.
+
+      53 | 
+      54 | test('assert.notStrictEqual', () => {
+    > 55 |   assert.notStrictEqual(1, 1, 'My custom error message');
+      56 | });
+      57 | 
+      58 | test('assert.deepStrictEqual', () => {
       
       at __tests__/node_assertion_error.test.js:55:10
 
@@ -268,6 +357,13 @@ exports[`works with node assert 1`] = `
     -   \\"a\\": 2,
     +   \\"a\\": 1,
       }
+
+      57 | 
+      58 | test('assert.deepStrictEqual', () => {
+    > 59 |   assert.deepStrictEqual({a: 1}, {a: 2});
+      60 | });
+      61 | 
+      62 | test('assert.notDeepStrictEqual', () => {
       
       at __tests__/node_assertion_error.test.js:59:10
 
@@ -283,6 +379,13 @@ exports[`works with node assert 1`] = `
     Difference:
     
     Compared values have no visual difference.
+
+      61 | 
+      62 | test('assert.notDeepStrictEqual', () => {
+    > 63 |   assert.notDeepStrictEqual({a: 1}, {a: 1});
+      64 | });
+      65 | 
+      66 | test('assert.ifError', () => {
       
       at __tests__/node_assertion_error.test.js:63:10
 
@@ -301,6 +404,13 @@ exports[`works with node assert 1`] = `
     
     Message:
       Got unwanted exception.
+
+      69 | 
+      70 | test('assert.doesNotThrow', () => {
+    > 71 |   assert.doesNotThrow(() => {
+      72 |     throw Error('err!');
+      73 |   });
+      74 | });
       
       at __tests__/node_assertion_error.test.js:71:10
 
@@ -313,6 +423,12 @@ exports[`works with node assert 1`] = `
     
     Message:
       Missing expected exception.
+
+      75 | 
+      76 | test('assert.throws', () => {
+    > 77 |   assert.throws(() => {});
+      78 | });
+      79 | 
       
       at __tests__/node_assertion_error.test.js:77:10
 

integration_tests/__tests__/failures.test.js

@@ -72,6 +72,13 @@ test('works with node assert', () => {
       Got unwanted exception.
     err!
     err!
+
+      69 | 
+      70 | test('assert.doesNotThrow', () => {
+    > 71 |   assert.doesNotThrow(() => {
+      72 |     throw Error('err!');
+      73 |   });
+      74 | });
       
       at __tests__/node_assertion_error.test.js:71:10
 `);

packages/jest-message-util/package.json

@@ -8,6 +8,7 @@
   "license": "MIT",
   "main": "build/index.js",
   "dependencies": {
+    "@babel/code-frame": "^7.0.0-beta.35",
     "chalk": "^2.0.1",
     "micromatch": "^2.3.11",
     "slash": "^1.0.0",

packages/jest-message-util/src/index.js

@@ -10,10 +10,12 @@
 import type {Glob, Path} from 'types/Config';
 import type {AssertionResult, TestResult} from 'types/TestResult';
 
+import fs from 'fs';
 import path from 'path';
 import chalk from 'chalk';
 import micromatch from 'micromatch';
 import slash from 'slash';
+import {codeFrameColumns} from '@babel/code-frame';
 import StackUtils from 'stack-utils';
 
 let nodeInternals = [];
@@ -194,15 +196,45 @@ export const formatStackTrace = (
   testPath: ?Path,
 ) => {
   let lines = stack.split(/\n/);
+  let renderedCallsite = '';
   const relativeTestPath = testPath
     ? slash(path.relative(config.rootDir, testPath))
     : null;
   lines = removeInternalStackEntries(lines, options);
-  return lines
+
+  if (testPath) {
+    const topFrame = lines
+      .join('\n')
+      .trim()
+      .split('\n')[0];
+
+    const parsedFrame = StackUtils.parseLine(topFrame);
+
+    if (parsedFrame) {
+      renderedCallsite = codeFrameColumns(
+        fs.readFileSync(testPath, 'utf8'),
+        {
+          start: {line: parsedFrame.line},
+        },
+        {highlightCode: true},
+      );
+
+      renderedCallsite = renderedCallsite
+        .split('\n')
+        .map(line => MESSAGE_INDENT + line)
+        .join('\n');
+
+      renderedCallsite = `\n${renderedCallsite}\n`;
+    }
+  }
+
+  const stacktrace = lines
     .map(trimPaths)
     .map(formatPaths.bind(null, config, options, relativeTestPath))
     .map(line => STACK_INDENT + line)
     .join('\n');
+
+  return renderedCallsite + stacktrace;
 };
 
 export const formatResultsErrors = (