🐛 BUG: Incorrectly erroring for multiple outbound mocks for vitest pool worker

[tyler-goodwin]

Which Cloudflare product(s) does this pertain to?

Workers Vitest Integration

What version(s) of the tool(s) are you using?

0.1.12

What version of Node are you using?

20.11.0

What operating system and version are you using?

macOS Sonoma 14.4.1

Describe the Bug

Observed behavior

Incorrectly reporting conflicting miniflare errors

MiniflareCoreError [ERR_MULTIPLE_OUTBOUNDS]: Only one of `outboundService` or `fetchMock` may be specified per worker

Config:

import { defineWorkersConfig } from "@cloudflare/vitest-pool-workers/config";
import { MockAgent } from "undici";

const mockFetch = new MockAgent()

export default defineWorkersConfig({
  test: {
    poolOptions: {
      workers: {
        singleWorker: true,
        miniflare: {
          compatibilityDate: "2024-01-01",
          compatibilityFlags: ["nodejs_compat"],
          serviceBindings: {
            WORKER: "test-worker",
          },
          workers: [
            {
              name: "test-worker",
              modules: true,
              compatibilityDate: "2022-11-30",
              compatibilityFlags: ["nodejs_compat"],
              scriptPath: "./worker.js",
              fetchMock: mockFetch,
            }
          ]
        }
      },
    },
  },
});

Expected behavior

No error when trying to run tests

Steps to reproduce

Please see reproduction repo

Please provide a link to a minimal reproduction

https://github.com/tyler-goodwin/miniflare-fetch-mock-repro

Please provide any relevant error logs

npm test

> miniflare-fetch-mock-repro@1.0.0 test
> vitest

 DEV  v1.3.0 /Users/tgoodwin/work/miniflare-fetch-mock-repro

[vpw:inf] Starting single runtime for vitest.config.js...

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Vitest caught 1 unhandled error during the test run.
This might cause false positive tests. Resolve unhandled errors to make sure your tests are not affected.

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Unhandled Error ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
MiniflareCoreError [ERR_MULTIPLE_OUTBOUNDS]: Only one of `outboundService` or `fetchMock` may be specified per worker
 ❯ Object.transform node_modules/miniflare/dist/src/index.js:6401:13
 ❯ ZodEffects._parse node_modules/zod/lib/types.js:3050:39
 ❯ ZodEffects._parseSync node_modules/zod/lib/types.js:129:29
 ❯ ZodEffects.safeParse node_modules/zod/lib/types.js:159:29
 ❯ ZodEffects.parse node_modules/zod/lib/types.js:140:29
 ❯ parseWithRootPath node_modules/miniflare/dist/src/index.js:3889:19
 ❯ validateOptions node_modules/miniflare/dist/src/index.js:8056:36
 ❯ new Miniflare node_modules/miniflare/dist/src/index.js:8405:38
 ❯ getProjectMiniflare node_modules/@cloudflare/vitest-pool-workers/dist/pool/index.mjs:1214:20
 ❯ Object.runTests node_modules/@cloudflare/vitest-pool-workers/dist/pool/index.mjs:1460:26

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Serialized Error: { code: 'ERR_MULTIPLE_OUTBOUNDS' }
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 Test Files  no tests
      Tests  no tests
     Errors  1 error
   Start at  15:07:05
   Duration  59ms (transform 0ms, setup 0ms, collect 0ms, tests 0ms, environment 0ms, prepare 0ms)

 FAIL  Tests failed. Watching for file changes...
       press h to show help, press q to quit
[vpw:dbg] Shutting down runtimes...

[penalosa]

This seems to be because we parse Miniflare's config before starting up Miniflare, and then pass that parsed config to Miniflare when starting up the test runner. I don't think that's necessarily correct—as this issue shows the config is not necessarily roundtripable. I suspect we should either:

• Not parse Miniflare's config outside of Miniflare, or
• Remove Zod transform() calls in Miniflare's config, to make it roundtripable I think the first option is probably the best, but it will require some investigation to see why we were parsing the config outside of Miniflare in the first place.