Improve message/stack parsing for Babel code frame errors

CHANGELOG.md

@@ -64,6 +64,8 @@
 - `[expect]` Improves the failing message for `toStrictEqual` matcher. ([#7224](https://github.com/facebook/jest/pull/7224))
 - `[jest-mock]` [**BREAKING**] Fix bugs with mock/spy result tracking of recursive functions ([#6381](https://github.com/facebook/jest/pull/6381))
 - `[jest-resolve]` Fix not being able to resolve path to mapped file with custom platform ([#7312](https://github.com/facebook/jest/pull/7312))
+- `[jest-message-util]` Improve parsing of error messages for unusually formatted stack traces ([#7319](https://github.com/facebook/jest/pull/7319))
+- `[jest-runtime]` Ensure error message text is not lost on errors with code frames ([#7319](https://github.com/facebook/jest/pull/7319))
 
 ### Chore & Maintenance
 

e2e/__tests__/__snapshots__/expect-async-matcher.test.js.snap

@@ -9,9 +9,8 @@ exports[`shows the correct errors in stderr when failing tests 1`] = `
 
   ● fail with expected non promise values
 
-    Error
+    Expected value to have length:
 
-      Error: Expected value to have length:
         2
       Received:
         1
@@ -20,9 +19,8 @@ exports[`shows the correct errors in stderr when failing tests 1`] = `
 
   ● fail with expected non promise values and not
 
-    Error
+    Expected value to not have length:
 
-      Error: Expected value to not have length:
         2
       Received:
         1,2

e2e/__tests__/__snapshots__/failures.test.js.snap

@@ -13,9 +13,7 @@ exports[`not throwing Error objects 2`] = `
 "FAIL __tests__/throw_string.test.js
   ● Test suite failed to run
 
-    Error
-
-      banana
+    banana
 
 "
 `;

packages/jest-message-util/src/__tests__/__snapshots__/messages.test.js.snap

@@ -22,6 +22,22 @@ exports[`formatStackTrace should strip node internals 1`] = `
 "
 `;
 
+exports[`retains message in babel code frame error 1`] = `
+"<bold><red>  <bold>● <bold>Babel test</></>
+
+
+        packages/react/src/forwardRef.js: Unexpected token, expected , (20:10)
+<dim></>
+<dim>          </> <gray> 18 | </>        <cyan>false</><yellow>,</></>
+<dim>           <gray> 19 | </>        <green>'forwardRef requires a render function but received a \`memo\` '</> </>
+<dim>          <red><bold>><dim></><gray> 20 | </>          <green>'component. Instead of forwardRef(memo(...)), use '</> <yellow>+</></>
+<dim>           <gray>    | </>          <red><bold>^<dim></></>
+<dim>           <gray> 21 | </>          <green>'memo(forwardRef(...)).'</><yellow>,</></>
+<dim>           <gray> 22 | </>      )<yellow>;</></>
+<dim>           <gray> 23 | </>    } <cyan>else</> <cyan>if</> (<cyan>typeof</> render <yellow>!==</> <green>'function'</>) {</></>
+"
+`;
+
 exports[`should exclude jasmine from stack trace for Unix paths. 1`] = `
 "<bold><red>  <bold>● <bold>Unix test</></>
 

packages/jest-message-util/src/__tests__/messages.test.js

@@ -58,6 +58,19 @@ const vendorStack =
       at Object.asyncFn (__tests__/vendor/sulu/node_modules/sulu-content-bundle/best_component.js:1:5)
 `;
 
+const babelStack =
+  '  ' +
+  `
+    packages/react/src/forwardRef.js: Unexpected token, expected , (20:10)
+    \u001b[0m \u001b[90m 18 | \u001b[39m        \u001b[36mfalse\u001b[39m\u001b[33m,\u001b[39m
+     \u001b[90m 19 | \u001b[39m        \u001b[32m'forwardRef requires a render function but received a \`memo\` '\u001b[39m 
+    \u001b[31m\u001b[1m>\u001b[22m\u001b[39m\u001b[90m 20 | \u001b[39m          \u001b[32m'component. Instead of forwardRef(memo(...)), use '\u001b[39m \u001b[33m+\u001b[39m
+     \u001b[90m    | \u001b[39m          \u001b[31m\u001b[1m^\u001b[22m\u001b[39m
+     \u001b[90m 21 | \u001b[39m          \u001b[32m'memo(forwardRef(...)).'\u001b[39m\u001b[33m,\u001b[39m
+     \u001b[90m 22 | \u001b[39m      )\u001b[33m;\u001b[39m
+     \u001b[90m 23 | \u001b[39m    } \u001b[36melse\u001b[39m \u001b[36mif\u001b[39m (\u001b[36mtypeof\u001b[39m render \u001b[33m!==\u001b[39m \u001b[32m'function'\u001b[39m) {\u001b[0m
+`;
+
 it('should exclude jasmine from stack trace for Unix paths.', () => {
   const messages = formatResultsErrors(
     [
@@ -134,3 +147,23 @@ it('should not exclude vendor from stack trace', () => {
 
   expect(messages).toMatchSnapshot();
 });
+
+it('retains message in babel code frame error', () => {
+  const messages = formatResultsErrors(
+    [
+      {
+        ancestorTitles: [],
+        failureMessages: [babelStack],
+        title: 'Babel test',
+      },
+    ],
+    {
+      rootDir: '',
+    },
+    {
+      noStackTrace: false,
+    },
+  );
+
+  expect(messages).toMatchSnapshot();
+});

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

@@ -62,7 +62,6 @@ const TITLE_BULLET = chalk.bold('\u25cf ');
 const STACK_TRACE_COLOR = chalk.dim;
 const STACK_PATH_REGEXP = /\s*at.*\(?(\:\d*\:\d*|native)\)?/;
 const EXEC_ERROR_MESSAGE = 'Test suite failed to run';
-const ERROR_TEXT = 'Error: ';
 const NOT_EMPTY_LINE_REGEXP = /^(?!$)/gm;
 
 const indentAllLines = (lines: string, indent: string) =>
@@ -335,13 +334,18 @@ export const separateMessageFromStack = (content: string) => {
     return {message: '', stack: ''};
   }
 
-  const messageMatch = content.match(/(^(.|\n)*?(?=\n\s*at\s.*\:\d*\:\d*))/);
-  let message = messageMatch ? messageMatch[0] : 'Error';
-  const stack = messageMatch ? content.slice(message.length) : content;
-  // If the error is a plain error instead of a SyntaxError or TypeError
-  // we remove it from the message because it is generally not useful.
-  if (message.startsWith(ERROR_TEXT)) {
-    message = message.substr(ERROR_TEXT.length);
+  // All lines up to what looks like a stack -- or if nothing looks like a stack
+  // (maybe it's a code frame instead), just the first non-empty line.
+  // If the error is a plain "Error:" instead of a SyntaxError or TypeError we
+  // remove the prefix from the message because it is generally not useful.
+  const messageMatch = content.match(
+    /^(?:Error: )?([\s\S]*?(?=\n\s*at\s.*\:\d*\:\d*)|\s*.*)([\s\S]*)$/,
+  );
+  if (!messageMatch) {
+    // For flow
+    throw new Error('If you hit this error, the regex above is buggy.');
   }
+  const message = messageMatch[1];
+  const stack = messageMatch[2];
   return {message, stack};
 };

packages/jest-runtime/src/script_transformer.js

@@ -329,7 +329,7 @@ export default class ScriptTransformer {
       };
     } catch (e) {
       if (e.codeFrame) {
-        e.stack = e.codeFrame;
+        e.stack = e.message + '\n' + e.codeFrame;
       }
 
       if (