child_process: harden fork arguments validation

[ZYSzys]

Ensure that the first argument modulePath of fork method must be provided and be of type string.

Also merge test-child-process-fork-options.js(which ensure that the second argument can be undefined or null) into test-child-process-fork-args.js

Maybe should be semver-major since different error now ?

Before:

> child_process.fork()
...
> internal/modules/cjs/loader.js:651
    throw err;
    ^

Error: Cannot find module '/Users/zyszys/Projects/nodejs/node/undefined'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:649:15)
    at Function.Module._load (internal/modules/cjs/loader.js:575:25)
    at Function.Module.runMain (internal/modules/cjs/loader.js:862:12)
    at internal/main/run_main_module.js:21:11

After validation:

> child_process.fork()
Thrown:
TypeError [ERR_INVALID_ARG_TYPE]: The "modulePath" argument must be of type string. Received type undefined
    at validateString (internal/validators.js:105:11)
    at Object.fork (child_process.js:63:3)
    at repl:1:15
    at Script.runInThisContext (vm.js:124:20)
    at REPLServer.defaultEval (repl.js:360:29)
    at bound (domain.js:413:14)
    at REPLServer.runBound [as eval] (domain.js:426:12)
    at REPLServer.onLine (repl.js:667:10)
    at REPLServer.emit (events.js:199:15)
    at REPLServer.EventEmitter.emit (domain.js:469:20)

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

[nodejs-github-bot]

Lite-CI: https://ci.nodejs.org/job/node-test-pull-request-lite-pipeline/3133

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/22095/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/22131/

[ZYSzys]

/cc @nodejs/child_process Could you please have a review on this?

[BridgeAR]

Since this was broken before (as in: would always result in an error), should this really be semver-major?

[ZYSzys]

I’m not sure exactly, but one thing would be broken now is, e.g, child_process.fork(1) would throw error even if we have 1.js in current dir(we should use child_process.fork(‘1’)).

[ZYSzys]

Ping @nodejs/tsc , can I get some reviews since it's semver major ?

[ZYSzys]

Landed in 9ad5106.

Thanks all!