test_runner: display warn/error diagnostics with the dot reporter

lib/internal/test_runner/harness.js

@@ -178,7 +178,7 @@ function configureCoverage(rootTest, globalOptions) {
   } catch (err) {
     const msg = `Warning: Code coverage could not be enabled. ${err}`;
 
-    rootTest.diagnostic(msg);
+    rootTest.diagnostic(msg, 'warn');
     rootTest.harness.success = false;
     process.exitCode = kGenericUserError;
   }
@@ -194,15 +194,15 @@ function collectCoverage(rootTest, coverage) {
   try {
     summary = coverage.summary();
   } catch (err) {
-    rootTest.diagnostic(`Warning: Could not report code coverage. ${err}`);
+    rootTest.diagnostic(`Warning: Could not report code coverage. ${err}`, 'warn');
     rootTest.harness.success = false;
     process.exitCode = kGenericUserError;
   }
 
   try {
     coverage.cleanup();
   } catch (err) {
-    rootTest.diagnostic(`Warning: Could not clean up code coverage. ${err}`);
+    rootTest.diagnostic(`Warning: Could not clean up code coverage. ${err}`, 'warn');
     rootTest.harness.success = false;
     process.exitCode = kGenericUserError;
   }

lib/internal/test_runner/reporter/dot.js

@@ -4,12 +4,17 @@ const {
   MathMax,
 } = primordials;
 const colors = require('internal/util/colors');
-const { formatTestReport } = require('internal/test_runner/reporter/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 diagnosticWarnings = [];
   for await (const { type, data } of source) {
     if (type === 'test:pass') {
       yield `${colors.green}.${colors.reset}`;
@@ -18,6 +23,9 @@ module.exports = async function* dot(source) {
       yield `${colors.red}X${colors.reset}`;
       ArrayPrototypePush(failedTests, data);
     }
+    if (type === 'test:diagnostic' && (data.level === 'warn' || data.level === 'error')) {
+      ArrayPrototypePush(diagnosticWarnings, data);
+    }
     if ((type === 'test:fail' || type === 'test:pass') && ++count === columns) {
       yield '\n';
 
@@ -27,6 +35,12 @@ module.exports = async function* dot(source) {
     }
   }
   yield '\n';
+  if (diagnosticWarnings.length > 0) {
+    for (const diagnostic of diagnosticWarnings) {
+      const diagnosticColor = reporterColorMap[diagnostic.level] || reporterColorMap['test:diagnostic'];
+      yield `${diagnosticColor}${reporterUnicodeSymbolMap['test:diagnostic']}${diagnostic.message}${colors.white}\n`;
+    }
+  }
   if (failedTests.length > 0) {
     yield `\n${colors.red}Failed tests:${colors.white}\n\n`;
     for (const test of failedTests) {

lib/internal/test_runner/test.js

@@ -312,8 +312,8 @@ class TestContext {
     return Number(envWorkerId) || undefined;
   }
 
-  diagnostic(message) {
-    this.#test.diagnostic(message);
+  diagnostic(message, level = 'info') {
+    this.#test.diagnostic(message, level);
   }
 
   log(message, data) {
@@ -525,8 +525,8 @@ class SuiteContext {
     return this.#suite.attempt ?? 0;
   }
 
-  diagnostic(message) {
-    this.#suite.diagnostic(message);
+  diagnostic(message, level = 'info') {
+    this.#suite.diagnostic(message, level);
   }
 
   log(message, data) {
@@ -1203,8 +1203,8 @@ class Test extends AsyncResource {
     this.message = message;
   }
 
-  diagnostic(message) {
-    ArrayPrototypePush(this.diagnostics, message);
+  diagnostic(message, level = 'info') {
+    ArrayPrototypePush(this.diagnostics, { __proto__: null, message, level });
   }
 
   log(message, data) {
@@ -1551,7 +1551,7 @@ class Test extends AsyncResource {
       const coverage = harness.coverage();
       harness.snapshotManager?.writeSnapshotFiles();
       for (let i = 0; i < diagnostics.length; i++) {
-        reporter.diagnostic(nesting, loc, diagnostics[i]);
+        reporter.diagnostic(nesting, loc, diagnostics[i].message, diagnostics[i].level);
       }
 
       const duration = this.duration();
@@ -1693,7 +1693,8 @@ class Test extends AsyncResource {
     }
 
     for (let i = 0; i < this.diagnostics.length; i++) {
-      this.reporter.diagnostic(this.nesting, this.loc, this.diagnostics[i]);
+      const { message, level } = this.diagnostics[i];
+      this.reporter.diagnostic(this.nesting, this.loc, message, level);
     }
   }
 

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

@@ -0,0 +1,2 @@
+.
+ℹ Warning: Could not report code coverage. Error: Failed to collect coverage

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

@@ -0,0 +1,16 @@
+// Test that the output of test-runner/output/coverage_failure.js matches
+// test-runner/output/dot_coverage_failure.snapshot when using the dot reporter
+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/coverage_failure.js'),
+  defaultTransform,
+  { flags: ['--test-reporter=dot', '--test-coverage-exclude=!test/**'] },
+);