lib: source maps filter null prefix

Fixes: nodejs#42417

PR-URL: nodejs#42522
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/source_map/prepare_stack_trace.js

@@ -88,8 +88,9 @@ const prepareStackTrace = (globalThis, error, trace) => {
           }
           // Construct call site name based on: v8.dev/docs/stack-trace-api:
           const fnName = t.getFunctionName() ?? t.getMethodName();
-          const originalName = `${t.getTypeName() !== 'global' ?
-            `${t.getTypeName()}.` : ''}${fnName || '<anonymous>'}`;
+          const typeName = t.getTypeName();
+          const namePrefix = typeName !== null && typeName !== 'global' ? `${typeName}.` : '';
+          const originalName = `${namePrefix}${fnName || '<anonymous>'}`;
           // The original call site may have a different symbol name
           // associated with it, use it:
           const prefix = (name && name !== originalName) ?

test/fixtures/source-map/throw-async.mjs

@@ -0,0 +1,11 @@
+const message = 'Message ' + Math.random();
+export async function Throw() {
+    throw new Error(message);
+}
+await Throw();
+// To recreate:
+//
+// npx tsc --module esnext --target es2017 --outDir test/fixtures/source-map --sourceMap test/fixtures/source-map/throw-async.ts
+// + rename js to mjs
+// + rename js to mjs in source map comment in mjs file
+//# sourceMappingURL=throw-async.mjs.map

test/fixtures/source-map/throw-async.ts

@@ -0,0 +1,13 @@
+const message = 'Message ' + Math.random();
+
+export async function Throw() {
+  throw new Error(message)
+}
+
+await Throw();
+
+// To recreate:
+//
+// npx tsc --module esnext --target es2017 --outDir test/fixtures/source-map --sourceMap test/fixtures/source-map/throw-async.ts
+// + rename js to mjs
+// + rename js to mjs in source map comment in mjs file

test/parallel/test-source-map-enable.js

@@ -343,6 +343,22 @@ function nextdir() {
   assert.ok(sourceMap);
 }
 
+// Does not include null for async/await with esm
+// Refs: https://github.com/nodejs/node/issues/42417
+{
+  const output = spawnSync(process.execPath, [
+    '--enable-source-maps',
+    require.resolve('../fixtures/source-map/throw-async.mjs'),
+  ]);
+  // Error in original context of source content:
+  assert.match(
+    output.stderr.toString(),
+    /throw new Error\(message\)\r?\n.*\^/
+  );
+  // Rewritten stack trace:
+  assert.match(output.stderr.toString(), /at Throw \([^)]+throw-async\.ts:4:9\)/);
+}
+
 function getSourceMapFromCache(fixtureFile, coverageDirectory) {
   const jsonFiles = fs.readdirSync(coverageDirectory);
   for (const jsonFile of jsonFiles) {