lib: fix ERR_INVALID_ARG_TYPE with --enable-source-maps

Signed-off-by: June Kim <kimjune01@gmail.com>

Author: kimjune01

lib/internal/errors/error_source.js

@@ -32,14 +32,19 @@ function getErrorSourceLocation(error) {
     startColumn,
   } = pos;
 
+  if (!sourceLine) {
+    return;
+  }
+
   // Source map is not enabled. Return the source line directly.
   if (!getSourceMapsSupport().enabled) {
     return { sourceLine, startColumn };
   }
 
   const sm = findSourceMap(scriptResourceName);
   if (sm === undefined) {
-    return;
+    // No source map for this file; use the generated source line.
+    return { sourceLine, startColumn };
   }
   const {
     originalLine,
@@ -49,7 +54,9 @@ function getErrorSourceLocation(error) {
   const originalSourceLine = getSourceLine(sm, originalSource, originalLine, originalColumn);
 
   if (!originalSourceLine) {
-    return;
+    // Source map exists but original source is unavailable; use the
+    // generated source line rather than returning undefined.
+    return { sourceLine, startColumn };
   }
 
   return {

test/fixtures/source-map/assert-no-source-map.cjs

@@ -0,0 +1,15 @@
+'use strict';
+
+// Fixture for test/parallel/test-assert-ok-source-maps.js (CommonJS variant).
+// See assert-no-source-map.mjs for the rationale (issue #63169).
+const assert = require('node:assert');
+
+try {
+  assert.ok(false);
+} catch (e) {
+  process.stdout.write(e.constructor.name + '\n');
+  process.stdout.write(e.code + '\n');
+  process.stdout.write(e.message + '\n');
+  process.exit(0);
+}
+process.exit(1);

test/fixtures/source-map/assert-no-source-map.mjs

@@ -0,0 +1,16 @@
+// Fixture for test/parallel/test-assert-ok-source-maps.js.
+// Run with --enable-source-maps; the file has no source map, so the error's
+// source line resolution must fall back to the generated line instead of
+// throwing ERR_INVALID_ARG_TYPE (regression test for
+// https://github.com/nodejs/node/issues/63169).
+import { strict as assert } from 'node:assert';
+
+try {
+  assert(false);
+} catch (e) {
+  process.stdout.write(e.constructor.name + '\n');
+  process.stdout.write(e.code + '\n');
+  process.stdout.write(e.message + '\n');
+  process.exit(0);
+}
+process.exit(1);

test/parallel/test-assert-ok-source-maps.js

@@ -0,0 +1,38 @@
+'use strict';
+
+// Regression test for https://github.com/nodejs/node/issues/63169
+// When --enable-source-maps is enabled but the script has no source map,
+// assert(false) should throw AssertionError, not TypeError ERR_INVALID_ARG_TYPE.
+
+require('../common');
+const assert = require('node:assert');
+const { spawnSync } = require('node:child_process');
+const { test } = require('node:test');
+const fixtures = require('../common/fixtures');
+
+function runWithSourceMaps(fixture) {
+  return spawnSync(process.execPath, [
+    '--enable-source-maps',
+    fixtures.path('source-map', fixture),
+  ]);
+}
+
+test('assert(false) in .mjs with --enable-source-maps throws AssertionError', () => {
+  const result = runWithSourceMaps('assert-no-source-map.mjs');
+
+  assert.strictEqual(result.status, 0, `process exited with ${result.status}: ${result.stderr}`);
+  const lines = result.stdout.toString().trim().split('\n');
+  assert.strictEqual(lines[0], 'AssertionError');
+  assert.strictEqual(lines[1], 'ERR_ASSERTION');
+  assert.match(lines[2], /assert\(false\)/);
+});
+
+test('assert.ok(false) in .cjs with --enable-source-maps throws AssertionError', () => {
+  const result = runWithSourceMaps('assert-no-source-map.cjs');
+
+  assert.strictEqual(result.status, 0, `process exited with ${result.status}: ${result.stderr}`);
+  const lines = result.stdout.toString().trim().split('\n');
+  assert.strictEqual(lines[0], 'AssertionError');
+  assert.strictEqual(lines[1], 'ERR_ASSERTION');
+  assert.match(lines[2], /assert\.ok\(false\)/);
+});