feat: make error output nicer

package.json

@@ -41,6 +41,7 @@
     ]
   },
   "dependencies": {
-    "chalk": "^2.3.0"
+    "chalk": "^2.3.0",
+    "strip-ansi": "4.0.0"
   }
 }

src/LineWriter.js

@@ -98,11 +98,13 @@ class LineWriter {
 
   formatFailureMessage (message) {
     const [firstLine, ...lines] = message.split('\n');
-    const formattedLines = [];
+    const outputLines = [];
     const whitespace = '  ';
 
-    const push = (line) => formattedLines.push(formatComment(whitespace + line));
-    const pushTraceLine = (line) => push(chalk`  {grey ${line}}`);
+    const push = (line) => {
+      outputLines.push(line);
+    };
+    const pushTraceLine = (line) => push(chalk`    {grey ${line}}`);
     const pushTraceLineDim = (line) => pushTraceLine(chalk`{dim ${line}}`);
 
     let firstLineFormatted = firstLine;
@@ -115,9 +117,22 @@ class LineWriter {
     push('');
 
     let internalsStarted = false;
+    let isFirstTraceLine = true;
 
     for (const line of lines) {
       if (line.match(REG_AT)) {
+        if (isFirstTraceLine) {
+          isFirstTraceLine = false;
+
+          const isLastLineBlank = outputLines[outputLines.length - 1] === '';
+
+          if (!isLastLineBlank) {
+            push('');
+          }
+          push(chalk`{bold.dim Stack trace:}`);
+          push('');
+        }
+
         const matches = line.match(REG_TRACE_LINE);
 
         if (matches) {
@@ -139,13 +154,12 @@ class LineWriter {
         }
       } else {
         push(line);
-        push('');
       }
     }
 
     push('');
 
-    return formattedLines.join('\n');
+    return outputLines.map((line) => formatComment(whitespace + line)).join('\n');
   }
 
   errors (messages) {

test/TapReporter.spec.js

@@ -72,14 +72,8 @@ describe('TapReporter', () => {
     const options = {};
     const tapReporter = new TapReporter(globalConfig, options);
 
-    expect(tapReporter._globalConfig).toBe(globalConfig);
-    expect(tapReporter._options).toBe(options);
-  });
-
-  test('must set _shouldFail to false by default', () => {
-    const tapReporter = new TapReporter();
-
-    expect(tapReporter._shouldFail).toBe(false);
+    expect(tapReporter.globalConfig).toBe(globalConfig);
+    expect(tapReporter.options).toBe(options);
   });
 
   test('must log the start of the tests', () => {
@@ -128,7 +122,7 @@ describe('TapReporter', () => {
       expect(tapReporter.writer.pending.mock.calls).toMatchSnapshot();
     });
 
-    test.only('TapReporter onTestResults must output all the tests on a suite tests', () => {
+    test('must output all the tests on a suite tests', () => {
       const tapReporter = new TapReporter();
 
       tapReporter.onTestResult({}, severalTestsSuite);