node-executor: include err message in stack trace (#40606)

This fixes our implementation of `Error.prepareStackTrace` to include the error message when available. This matches the default behavior in v8/Node.js (https://v8.dev/docs/stack-trace-api) and can make it easier for Convex users to debug their apps. This also helps us internally understand errors in node-executor integration tests.

GitOrigin-RevId: 2f4f579379c5eab68c53de9e7e3e77c89b7b0710

Author: Nicolapps

npm-packages/js-integration-tests/convex/stacktraceNode.ts

@@ -50,3 +50,7 @@ async function wontBeInTheStackTrace(): Promise<string> {
     });
   });
 }
+
+export const errorWithMessage = action(() => {
+  return new Error("custom error message").stack;
+});

npm-packages/js-integration-tests/stacktrace_node.test.ts

@@ -82,4 +82,12 @@ describe("Node.js user space stack traces", () => {
     expect(canonicalResult).toEqual(canonicalExpected);
     // sometimes flakes at 20000ms
   }, 30000);
+
+  test("stack trace with an error message", async () => {
+    const result = await client.action(api.stacktraceNode.errorWithMessage);
+    const canonicalResult = canonicalize(result);
+    expect(
+      canonicalResult?.startsWith(`Error: custom error message\n    at `),
+    ).toBe(true);
+  }, 30000);
 });

npm-packages/node-executor/src/errors.ts

@@ -100,7 +100,9 @@ export function registerPrepareStackTrace(modulesDir: string) {
     //
     // TODO find a library to do this properly: once we provide it libraries will depend on it matching Node.js stack traces.
 
-    return `Error\n${frameData
+    const errorMessage = extractErrorMessage(error);
+
+    return `Error${errorMessage !== "" ? `: ${errorMessage}` : ""}\n${frameData
       .map((frame) => formatTraceLine(frame))
       .join("\n")}`;
   };