Support NestJS (test with jest)

[birkskyum]

Repro:

• git clone https://github.com/nestjs/typescript-starter.git project (From Nest docs frontpage)
• cd project
• deno task test or deno task --unstable test or deno --unstable task test

Expected:

$ jest
 PASS  src/app.controller.spec.ts
  AppController
    getHello
      ✓ should return "Hello World!" (1 ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        1.068 s
Ran all test suites.

Actual

➜ deno --unstable task test
Warning Currently only basic package.json `scripts` are supported. Programs like `rimraf` or `cross-env` will not work correctly. This will be fixed in an upcoming release.
Task test jest
Unstable API 'Deno.connect'. The --unstable flag must be provided.

[birkskyum]

And trying to bypass this using deno --unstable run -A npm:jest yields:

➜ deno --unstable run -A npm:jest
watchman warning:  Recrawled this watch 5 times, most recently because:
MustScanSubDirs UserDroppedTo resolve, please review the information on
https://facebook.github.io/watchman/docs/troubleshooting.html#recrawl
To clear this warning, run:
`watchman watch-del '/Users/admin/repos/deno-kitchensink/nest-project' ; watchman watch-project '/Users/admin/repos/deno-kitchensink/nest-project'`

TypeError: this._child.send is not a function
    at ChildProcessWorker.initialize (file:///Users/admin/repos/deno-kitchensink/nest-project/node_modules/.deno/jest-worker@29.7.0/node_modules/jest-worker/build/workers/ChildProcessWorker.js:169:17)

[bartlomieju]

This is blocked by IPC support in node:child_process module. I will be looking into that.

[birkskyum]

With deno 1.38, I can't get past this message:

➜ deno task --unstable test           
Task test jest
Unstable API 'Deno.connect'. The --unstable flag must be provided.

[bartlomieju]

@birkskyum out of curiosity - does it get any further if you create deno.json with:

{
  "unstable": ["net"]
}

?

[birkskyum]

Yes, with the deno.json I see:

➜ deno task test
Task test jest
TypeError: this._child.send is not a function
    at ChildProcessWorker.initialize (file:///Users/admin/repos/nest-test/project/node_modules/.deno/jest-worker@29.7.0/node_modules/jest-worker/build/workers/ChildProcessWorker.js:169:17)

[bartlomieju]

So we're back at the missing IPC support - good news is: we figured out a way forward to provide this mechanism and I'll be working on PoC for Unix systems this week.

[malthe]

You can run tests in-band using -i which doesn't require a child-process worker.

$ deno --unstable run -A npm:jest -i

But Jest relies on v8.serialize which is not implemented by Deno. The compatibility notes mention that:

[these APIs] could be polyfilled, but due inherent lack of format stability between the V8 versions, the Deno team is considering requiring a special flag to use them.

[birkskyum]

with deno 1.39 i get:

➜ deno task test 
Task test jest
Error: Not implemented: v8.serialize
    at notImplemented (ext:deno_node/_utils.ts:9:9)
    at serialize (node:v8:59:3)
    at HasteMap._persist (file:///Users/admin/repos/deno-kitchensink/project/node_modules/.deno/jest-haste-map@29.7.0/node_modules/jest-haste-map/build/index.js:716:26)
    at file:///Users/admin/repos/deno-kitchensink/project/node_modules/.deno/jest-haste-map@29.7.0/node_modules/jest-haste-map/build/index.js:380:16
    at Object.runMicrotasks (ext:core/01_core.js:820:30)
    at processTicksAndRejections (ext:deno_node/_next_tick.ts:53:10)
    at runNextTicks (ext:deno_node/_next_tick.ts:71:3)
    at eventLoopTick (ext:core/01_core.js:188:21)
    at async file:///Users/admin/repos/deno-kitchensink/project/node_modules/.deno/@jest+core@29.7.0/node_modules/@jest/core/build/cli/index.js:268:9
    at async Promise.all (index 0)

[GerbenRampaart]

I tried the same thing. Deno 1.43.1.

Cloned the typescript-starter like @birkskyum

TypeError: Class constructor Process cannot be invoked without 'new'

[GerbenRampaart]

Since I'm invested in seeing NestJs properly supported by Deno or Bun (we have many apis in our corporation developed in nest) I did some additional testing.

So I created a brand new project with the nest cli and made the following changes to get as close to a runnable project as possible:

• app.controller.spec.ts was renamed to app.controller.test.ts
• app.controller.test.ts now has a unit test according to Deno.test
• All imports have .ts postfixed to them to prevent sloppy imports warning.
• Deno initialize workspace was run to add the settings.json.
• Deno init was run to add a deno.json
• "experimentalDecorators": true was added to compilerOptions in deno.json

Running deno test yields these results:

Please verify these results by cloning:
https://github.com/GerbenRampaart/deno-nestjs-vanilla

This error is decorator related right?