fix(cli): propagate delegated generator return value for mpp/x402 pay and status (#19)

Author: nkavian

.changeset/propagate-pay-status-generator-return.md

@@ -0,0 +1,12 @@
+---
+'@inflowpayai/inflow': patch
+---
+
+Propagate the terminal result of `mpp`/`x402` `pay` and `status` in agent mode.
+
+These commands delegate to async-generator pipelines that surface terminal failures as the generator's return value
+(`return c.error(...)`), not as a yielded chunk. The command wrappers consumed the delegate with a bare `yield*`, which
+forwards yielded chunks but drops the return value, so the wrapper returned `undefined`. In buffered agent output
+(`--format json`) the framework then took the success path and emitted `{ ok: true, data: [] }` with exit code 0,
+swallowing errors such as `NO_FILTERED_MATCH`. The wrappers now `return yield*` the delegate, so the error envelope is
+emitted with a non-zero exit code.

packages/cli/src/commands/mpp/index.tsx

@@ -279,7 +279,7 @@ async function* runPayCommand(
   inflow: Inflow,
   authStorage: AuthStorage,
   apiBaseUrl: string,
-): AsyncGenerator<unknown> {
+): AsyncGenerator<unknown, unknown> {
   assertSessionGuard(c, authStorage, inflow);
 
   let probeOptions: SellerProbeOptions;
@@ -359,7 +359,7 @@ async function* runStatusCommand(
   c: StatusCommandContext,
   inflow: Inflow,
   authStorage: AuthStorage,
-): AsyncGenerator<unknown> {
+): AsyncGenerator<unknown, unknown> {
   assertSessionGuard(c, authStorage, inflow);
 
   if (!c.agent && !c.formatExplicit) {
@@ -560,7 +560,7 @@ export function createMppCli(inflow: Inflow, authStorage: AuthStorage, apiBaseUr
     options: payOptions,
     outputPolicy: 'agent-only' as const,
     async *run(c) {
-      yield* runPayCommand(c, inflow, authStorage, apiBaseUrl);
+      return yield* runPayCommand(c, inflow, authStorage, apiBaseUrl);
     },
   });
 
@@ -570,7 +570,7 @@ export function createMppCli(inflow: Inflow, authStorage: AuthStorage, apiBaseUr
     options: statusOptions,
     outputPolicy: 'agent-only' as const,
     async *run(c) {
-      yield* runStatusCommand(c, inflow, authStorage);
+      return yield* runStatusCommand(c, inflow, authStorage);
     },
   });
 

packages/cli/src/commands/x402/index.tsx

@@ -261,7 +261,7 @@ async function* runPayCommand(
   inflow: Inflow,
   authStorage: AuthStorage,
   apiBaseUrl: string,
-): AsyncGenerator<unknown> {
+): AsyncGenerator<unknown, unknown> {
   assertSessionGuard(c, authStorage, inflow);
 
   let probeOptions: SellerProbeOptions;
@@ -348,7 +348,7 @@ async function* runStatusCommand(
   c: StatusCommandContext,
   inflow: Inflow,
   authStorage: AuthStorage,
-): AsyncGenerator<unknown> {
+): AsyncGenerator<unknown, unknown> {
   assertSessionGuard(c, authStorage, inflow);
 
   if (!c.agent && !c.formatExplicit) {
@@ -560,7 +560,7 @@ export function createX402Cli(inflow: Inflow, authStorage: AuthStorage, apiBaseU
     options: payOptions,
     outputPolicy: 'agent-only' as const,
     async *run(c) {
-      yield* runPayCommand(c, inflow, authStorage, apiBaseUrl);
+      return yield* runPayCommand(c, inflow, authStorage, apiBaseUrl);
     },
   });
 
@@ -570,7 +570,7 @@ export function createX402Cli(inflow: Inflow, authStorage: AuthStorage, apiBaseU
     options: statusOptions,
     outputPolicy: 'agent-only' as const,
     async *run(c) {
-      yield* runStatusCommand(c, inflow, authStorage);
+      return yield* runStatusCommand(c, inflow, authStorage);
     },
   });
 

packages/cli/test/integration/cli-smoke.test.ts

@@ -9,10 +9,13 @@
  */
 import { spawn } from 'node:child_process';
 import { existsSync, mkdtempSync, rmSync } from 'node:fs';
+import { createServer, type IncomingMessage, type Server, type ServerResponse } from 'node:http';
 import { tmpdir } from 'node:os';
 import { fileURLToPath } from 'node:url';
 import { resolve as resolvePath, dirname, join } from 'node:path';
 import { encode, renderChallengeHeader } from '@inflowpayai/mpp';
+import { encodePaymentRequiredHeader } from '@x402/core/http';
+import type { PaymentRequired } from '@x402/core/types';
 import { afterAll, beforeAll, describe, expect, it, vi } from 'vitest';
 
 vi.setConfig({ testTimeout: 15_000 });
@@ -38,6 +41,8 @@ interface RunResult {
   exitCode: number;
 }
 
+type TestServerHandler = (req: IncomingMessage, res: ServerResponse) => void;
+
 function run(args: string[], env: NodeJS.ProcessEnv = {}): Promise<RunResult> {
   return new Promise((resolveResult, reject) => {
     const childEnv: NodeJS.ProcessEnv = {
@@ -81,6 +86,32 @@ function parseAgentJson(out: string): unknown {
   }
 }
 
+async function withSeller(handler: TestServerHandler, test: (url: string) => Promise<void>): Promise<void> {
+  const server = createServer(handler);
+  await new Promise<void>((resolveListening) => {
+    server.listen(0, '127.0.0.1', resolveListening);
+  });
+  const address = server.address();
+  if (typeof address !== 'object' || address === null) {
+    await closeServer(server);
+    throw new Error('test server did not expose a port');
+  }
+  try {
+    await test(`http://127.0.0.1:${address.port}/paywalled`);
+  } finally {
+    await closeServer(server);
+  }
+}
+
+function closeServer(server: Server): Promise<void> {
+  return new Promise((resolveClosed, reject) => {
+    server.close((err) => {
+      if (err !== undefined) reject(err);
+      else resolveClosed();
+    });
+  });
+}
+
 describe('cli smoke', () => {
   it('the build produces an executable dist/cli.js', () => {
     expect(existsSync(cliBin)).toBe(true);
@@ -129,6 +160,69 @@ describe('cli smoke', () => {
     expect(`${result.stdout}${result.stderr}`).toContain('DECODE_FAILED');
   });
 
+  it('mpp pay --format json propagates a delegated generator NO_FILTERED_MATCH error', async () => {
+    const header = renderChallengeHeader({
+      id: 'chal-1',
+      realm: 'mpp.test',
+      method: 'inflow',
+      intent: 'charge',
+      request: encode({ amount: '10', currency: 'USDC', methodDetails: { rail: 'balance' } }),
+    });
+    await withSeller(
+      (_req, res) => {
+        res.writeHead(402, { 'WWW-Authenticate': header });
+        res.end('payment required');
+      },
+      async (url) => {
+        const result = await run(
+          ['mpp', 'pay', url, '--rail', 'instrument', '--format', 'json', '--interval', '0', '--no-show-body'],
+          { INFLOW_API_KEY: 'test-api-key' },
+        );
+        expect(result.exitCode).toBe(1);
+        expect(`${result.stdout}${result.stderr}`).toContain('NO_FILTERED_MATCH');
+        expect(result.stdout.trim()).not.toBe('[]');
+      },
+    );
+  });
+
+  it('x402 pay --format json propagates a delegated generator NO_FILTERED_MATCH error', async () => {
+    const header = encodePaymentRequiredHeader({
+      x402Version: 2,
+      resource: { url: 'https://seller.test/api', mimeType: 'application/json' },
+      accepts: [
+        {
+          scheme: 'balance',
+          network: 'inflow:1',
+          amount: '500',
+          payTo: 'inflow:abc',
+          maxTimeoutSeconds: 60,
+          asset: 'USDC',
+          extra: {},
+        },
+      ],
+    } satisfies PaymentRequired);
+    await withSeller(
+      (req, res) => {
+        if (req.url === '/v1/transactions/x402-supported') {
+          res.writeHead(200, { 'Content-Type': 'application/json' });
+          res.end(JSON.stringify({ kinds: [{ scheme: 'balance', network: 'inflow:1', x402Version: 2 }] }));
+          return;
+        }
+        res.writeHead(402, { 'PAYMENT-REQUIRED': header });
+        res.end('payment required');
+      },
+      async (url) => {
+        const result = await run(
+          ['x402', 'pay', url, '--scheme', 'exact', '--format', 'json', '--interval', '0', '--no-show-body'],
+          { INFLOW_API_KEY: 'test-api-key', INFLOW_BASE_URL: new URL(url).origin },
+        );
+        expect(result.exitCode).toBe(1);
+        expect(`${result.stdout}${result.stderr}`).toContain('NO_FILTERED_MATCH');
+        expect(result.stdout.trim()).not.toBe('[]');
+      },
+    );
+  });
+
   it('x402 decode --format json emits a DECODE_FAILED error envelope on garbage input', async () => {
     const result = await run(['x402', 'decode', 'garbage', '--format', 'json']);
     expect(result.exitCode).not.toBe(0);