refactor(test_runner): rewrite spec reporter to generator function

Author: himself65

lib/internal/test_runner/reporter/spec.js

@@ -11,8 +11,8 @@ const {
   SafeMap,
   StringPrototypeRepeat,
 } = primordials;
+
 const assert = require('assert');
-const Transform = require('internal/streams/transform');
 const { inspectWithNoCustomRetry } = require('internal/errors');
 const { green, blue, red, white, gray, shouldColorize } = require('internal/util/colors');
 const { kSubtestsFailed } = require('internal/test_runner/test');
@@ -27,6 +27,7 @@ const colors = {
   'test:pass': green,
   'test:diagnostic': blue,
 };
+
 const symbols = {
   '__proto__': null,
   'test:fail': '\u2716 ',
@@ -36,27 +37,25 @@ const symbols = {
   'arrow:right': '\u25B6 ',
   'hyphen:minus': '\uFE63 ',
 };
-class SpecReporter extends Transform {
-  #stack = [];
-  #reported = [];
-  #indentMemo = new SafeMap();
-  #failedTests = [];
-  #cwd = process.cwd();
-
-  constructor() {
-    super({ __proto__: null, writableObjectMode: true });
-  }
 
-  #indent(nesting) {
-    let value = this.#indentMemo.get(nesting);
+module.exports = async function* specReporter(source) {
+  let stack = [];
+  let reported = [];
+  let indentMemo = new SafeMap();
+  let failedTests = [];
+  let cwd = process.cwd();
+
+  function indent(nesting) {
+    let value = indentMemo.get(nesting);
     if (value === undefined) {
       value = StringPrototypeRepeat('  ', nesting);
-      this.#indentMemo.set(nesting, value);
+      indentMemo.set(nesting, value);
     }
 
     return value;
   }
-  #formatError(error, indent) {
+
+  function formatError(error, indent) {
     if (!error) return '';
     const err = error.code === 'ERR_TEST_FAILURE' ? error.cause : error;
     const message = ArrayPrototypeJoin(
@@ -66,7 +65,8 @@ class SpecReporter extends Transform {
       ), `\n${indent}  `);
     return `\n${indent}  ${message}\n`;
   }
-  #formatTestReport(type, data, prefix = '', indent = '', hasChildren = false) {
+
+  function formatTestReport(type, data, prefix = '', indent = '', hasChildren = false) {
     let color = colors[type] ?? white;
     let symbol = symbols[type] ?? ' ';
     const { skip, todo } = data;
@@ -89,7 +89,8 @@ class SpecReporter extends Transform {
     }
     return `${prefix}${indent}${color}${symbol}${title}${white}${error}`;
   }
-  #handleTestReportEvent(type, data) {
+
+  function handleTestReportEvent(type, data) {
     const subtest = ArrayPrototypeShift(this.#stack); // This is the matching `test:start` event
     if (subtest) {
       assert(subtest.type === 'test:start');
@@ -113,7 +114,8 @@ class SpecReporter extends Transform {
     const indent = this.#indent(data.nesting);
     return `${this.#formatTestReport(type, data, prefix, indent, hasChildren)}\n`;
   }
-  #handleEvent({ type, data }) {
+
+  function handleEvent({ type, data }) {
     switch (type) {
       case 'test:fail':
         if (data.details?.error?.failureType !== kSubtestsFailed) {
@@ -134,25 +136,21 @@ class SpecReporter extends Transform {
         return getCoverageReport(this.#indent(data.nesting), data.summary, symbols['test:coverage'], blue, true);
     }
   }
-  _transform({ type, data }, encoding, callback) {
-    callback(null, this.#handleEvent({ __proto__: null, type, data }));
+
+  for await (const event of source) {
+    yield handleEvent(event);
   }
-  _flush(callback) {
-    if (this.#failedTests.length === 0) {
-      callback(null, '');
-      return;
-    }
+
+  if (failedTests.length !== 0) {
     const results = [`\n${colors['test:fail']}${symbols['test:fail']}failing tests:${white}\n`];
-    for (let i = 0; i < this.#failedTests.length; i++) {
-      const test = this.#failedTests[i];
-      const relPath = relative(this.#cwd, test.file);
-      const formattedErr = this.#formatTestReport('test:fail', test);
+    for (let i = 0; i < failedTests.length; i++) {
+      const test = failedTests[i];
+      const relPath = relative(cwd, test.file);
+      const formattedErr = formatTestReport('test:fail', test);
       const location = `test at ${relPath}:${test.line}:${test.column}`;
 
       ArrayPrototypePush(results, location, formattedErr);
     }
-    callback(null, ArrayPrototypeJoin(results, '\n'));
+    yield ArrayPrototypeJoin(results, '\n');
   }
-}
-
-module.exports = SpecReporter;
+};