test_runner: print coverage and diagnostics with dot reporter

lib/internal/test_runner/reporter/dot.js

@@ -4,12 +4,19 @@ const {
   MathMax,
 } = primordials;
 const colors = require('internal/util/colors');
-const { formatTestReport } = require('internal/test_runner/reporter/utils');
+const { getCoverageReport } = require('internal/test_runner/utils');
+const {
+  formatTestReport,
+  reporterColorMap,
+  reporterUnicodeSymbolMap,
+} = require('internal/test_runner/reporter/utils');
 
 module.exports = async function* dot(source) {
   let count = 0;
   let columns = getLineLength();
   const failedTests = [];
+  const diagnostics = [];
+  let coverage;
   for await (const { type, data } of source) {
     if (type === 'test:pass') {
       yield `${colors.green}.${colors.reset}`;
@@ -25,6 +32,12 @@ module.exports = async function* dot(source) {
       columns = getLineLength();
       count = 0;
     }
+    if (type === 'test:diagnostic') {
+      ArrayPrototypePush(diagnostics, data);
+    }
+    if (type === 'test:coverage') {
+      coverage = data;
+    }
   }
   yield '\n';
   if (failedTests.length > 0) {
@@ -33,6 +46,13 @@ module.exports = async function* dot(source) {
       yield formatTestReport('test:fail', test);
     }
   }
+  for (const diagnostic of diagnostics) {
+    const color = reporterColorMap[diagnostic.level] || reporterColorMap['test:diagnostic'];
+    yield `${color}${reporterUnicodeSymbolMap['test:diagnostic']}${diagnostic.message}${colors.white}\n`;
+  }
+  if (coverage) {
+    yield getCoverageReport('', coverage.summary, reporterUnicodeSymbolMap['test:coverage'], colors.blue, true);
+  }
 };
 
 function getLineLength() {

test/fixtures/test-runner/output/dot_reporter_coverage.mjs

@@ -0,0 +1,13 @@
+// Flags: --experimental-test-coverage --test-coverage-lines=99
+// here we can't import common module as the coverage will be different based on the system
+// Unused imports are here in order to populate the coverage report
+// eslint-disable-next-line no-unused-vars
+import * as a from '../coverage-snap/b.js';
+// eslint-disable-next-line no-unused-vars
+import * as b from '../coverage-snap/a.js';
+
+import { test } from 'node:test';
+
+process.stdout.columns = 80;
+
+test('passing test for dot coverage report');

test/fixtures/test-runner/output/dot_reporter_coverage.snapshot

@@ -0,0 +1,19 @@
+.
+
+ℹ Error: *% line coverage does not meet threshold of 99%.
+ℹ start of coverage report
+ℹ ------------------------------------------------------------------------------
+ℹ file                      | line % | branch % | funcs % | uncovered lines
+ℹ ------------------------------------------------------------------------------
+ℹ test                      |        |          |         |
+ℹ  fixtures                 |        |          |         |
+ℹ   test-runner             |        |          |         |
+ℹ    coverage-snap          |        |          |         |
+ℹ     a.js                  |  55.77 |   100.00 |    0.00 | 5-7 9-11 13-15 17-…
+ℹ     b.js                  |  45.45 |   100.00 |    0.00 | 5-7 9-11
+ℹ    output                 |        |          |         |
+ℹ     dot_reporter_cove….mjs | 100.00 |   100.00 |  100.00 |
+ℹ ------------------------------------------------------------------------------
+ℹ all files                 |  61.84 |   100.00 |    0.00 |
+ℹ ------------------------------------------------------------------------------
+ℹ end of coverage report

test/parallel/test-runner-coverage-thresholds.js

@@ -143,6 +143,23 @@ for (const coverage of coverages) {
     assert(!findCoverageFileForPid(result.pid));
   });
 
+  test(`test failing ${coverage.flag} with dot reporter`, () => {
+    const result = spawnSync(process.execPath, [
+      '--test',
+      '--experimental-test-coverage',
+      '--test-coverage-exclude=!test/**',
+      `${coverage.flag}=99`,
+      '--test-reporter', 'dot',
+      fixture,
+    ]);
+
+    const stdout = result.stdout.toString();
+    assert.match(stdout, RegExp(`Error: ${coverage.actual.toFixed(2)}% ${coverage.name} coverage does not meet threshold of 99%`));
+    assert.match(stdout, /start of coverage report/);
+    assert.strictEqual(result.status, 1);
+    assert(!findCoverageFileForPid(result.pid));
+  });
+
   test(`test out-of-range ${coverage.flag} (too high)`, () => {
     const result = spawnSync(process.execPath, [
       '--test',

test/test-runner/test-output-dot-reporter-coverage.mjs

@@ -0,0 +1,16 @@
+// Test that the output of test-runner/output/dot_reporter_coverage.mjs matches
+// test-runner/output/dot_reporter_coverage.snapshot
+import * as common from '../common/index.mjs';
+import * as fixtures from '../common/fixtures.mjs';
+import { spawnAndAssert, defaultTransform, ensureCwdIsProjectRoot } from '../common/assertSnapshot.js';
+
+if (!process.features.inspector) {
+  common.skip('inspector support required');
+}
+
+ensureCwdIsProjectRoot();
+await spawnAndAssert(
+  fixtures.path('test-runner/output/dot_reporter_coverage.mjs'),
+  defaultTransform,
+  { flags: ['--test-reporter=dot', '--test-coverage-exclude=!test/**'] },
+);