feat: expose ns-stack

Author: inca

src/main/global/InvokeHandler.ts

@@ -10,6 +10,7 @@ import { config } from 'mesh-config';
 import { dep } from 'mesh-ioc';
 
 import { PreconditionFailedError } from '../errors.js';
+import { parseStack } from '../util/stack.js';
 import { ModuleResolver } from './ModuleResolver.js';
 
 const EXTENDED_LATENCY_BUCKETS = [
@@ -101,9 +102,17 @@ export class InvokeHandler implements HttpHandler {
         try {
             const result = await computeFn(params, ctx);
             return resultToResponse(result);
-        } catch (error) {
+        } catch (error: any) {
             this.logger.warn('Graph error', { error });
-            return errorToResponse(error);
+            const res = errorToResponse(error);
+            const stack = parseStack(error?.stack ?? '');
+            // TODO observe if this is enough
+            const nodeUids = stack
+                .map(item => item.symbol)
+                .filter(symbol => symbol.startsWith('root:'))
+                .slice(0, 20);
+            res.headers['ns-stack'] = [nodeUids.join(',')];
+            return res;
         } finally {
             ctx.finalize();
         }

src/main/index.ts

@@ -5,3 +5,4 @@ export * from './global/MainHttpServer.js';
 export * from './global/ModuleResolver.js';
 export * from './global/UptimeChecker.js';
 export * from './sandbox.js';
+export * from './util/stack.js';

src/main/util/stack.ts

@@ -0,0 +1,20 @@
+export interface StackItem {
+    symbol: string;
+    source: string;
+}
+
+export function parseStack(stack: string): StackItem[] {
+    const lines = stack.split('\n').filter(line => line.trim().startsWith('at'));
+    const result: StackItem[] = [];
+    for (const line of lines) {
+        const match = /^\s*at(?:\s+async)?\s+(\S+)\s+\((.*)\)$/.exec(line);
+        if (!match) {
+            continue;
+        }
+        result.push({
+            symbol: match[1] ?? '',
+            source: match[2] ?? '',
+        });
+    }
+    return result;
+}

src/test/util.test.ts

@@ -0,0 +1,33 @@
+import assert from 'assert';
+
+import { parseStack } from '../main/util/stack.js';
+
+describe('parseStack', () => {
+    it('parses error stack', () => {
+        const stack = `
+         error: Error [BoomError]: Something bad happened
+      at compute (data:text/javascript;base64,...:1:340)
+      at root:Hvok7Y1K:SHpmQ5Wn (data:text/javascript;base64,...:1:936)
+      at root:Hvok7Y1K:result (data:text/javascript;base64,...:1:816)
+      at data:text/javascript;base64,...:1:686
+      at compute (data:text/javascript;base64,...:1:209)
+      at root:Hvok7Y1K (data:text/javascript;base64,...:1:664)
+      at async Promise.all (index 0)
+      at async root:result (data:text/javascript;base64,...:1:486)
+      at async compute (data:text/javascript;base64,...:1:1434)
+      at async derived.computeResponse (file:///foo/bar/baz/InvokeHandler.js:90:28)
+        `;
+        const parsed = parseStack(stack);
+        assert.deepStrictEqual(parsed, [
+            { symbol: 'compute', source: 'data:text/javascript;base64,...:1:340' },
+            { symbol: 'root:Hvok7Y1K:SHpmQ5Wn', source: 'data:text/javascript;base64,...:1:936' },
+            { symbol: 'root:Hvok7Y1K:result', source: 'data:text/javascript;base64,...:1:816' },
+            { symbol: 'compute', source: 'data:text/javascript;base64,...:1:209' },
+            { symbol: 'root:Hvok7Y1K', source: 'data:text/javascript;base64,...:1:664' },
+            { symbol: 'Promise.all', source: 'index 0' },
+            { symbol: 'root:result', source: 'data:text/javascript;base64,...:1:486' },
+            { symbol: 'compute', source: 'data:text/javascript;base64,...:1:1434' },
+            { symbol: 'derived.computeResponse', source: 'file:///foo/bar/baz/InvokeHandler.js:90:28' },
+        ]);
+    });
+});