util: fixes type in argument type validation error

[aoberoi]

The argument validation for superCtor should not output that superCtor.prototype
must be a Function, but rather it must be an Object.

Checklist

• commit message follows commit guidelines

[lpinca]

CI: https://ci.nodejs.org/job/node-test-pull-request/19663/

[Trott]

Test needs updating for this change.

12:54:18 not ok 2000 parallel/test-util-inherits
12:54:18   ---
12:54:18   duration_ms: 0.136
12:54:18   severity: fail
12:54:18   exitcode: 1
12:54:18   stack: |-
12:54:18     /Users/iojs/build/workspace/node-test-commit-osx/nodes/osx1011/test/common/index.js:580
12:54:18             throw new assert.AssertionError({
12:54:18             ^
12:54:18     
12:54:18     AssertionError [ERR_ASSERTION]: Expected "actual" to be reference-equal to "expected":
12:54:18     + actual - expected
12:54:18     
12:54:18       Comparison {
12:54:18         code: 'ERR_INVALID_ARG_TYPE',
12:54:18     +   message: 'The "superCtor.prototype" property must be of type Object. Received type undefined',
12:54:18     -   message: 'The "superCtor.prototype" property must be of type Function. Received type undefined',
12:54:18         type: [Function: TypeError]
12:54:18       }
12:54:18         at new AssertionError (internal/assert.js:396:11)
12:54:18         at Object.innerFn (/Users/iojs/build/workspace/node-test-commit-osx/nodes/osx1011/test/common/index.js:580:15)
12:54:18         at expectedException (assert.js:568:19)
12:54:18         at expectsError (assert.js:663:16)
12:54:18         at Function.throws (assert.js:694:3)
12:54:18         at Object.expectsError (/Users/iojs/build/workspace/node-test-commit-osx/nodes/osx1011/test/common/index.js:592:12)
12:54:18         at Object.<anonymous> (/Users/iojs/build/workspace/node-test-commit-osx/nodes/osx1011/test/parallel/test-util-inherits.js:86:8)
12:54:18         at Module._compile (internal/modules/cjs/loader.js:718:30)
12:54:18         at Object.Module._extensions..js (internal/modules/cjs/loader.js:729:10)
12:54:18         at Module.load (internal/modules/cjs/loader.js:617:32)
12:54:18   ...

[BridgeAR]

Ping @aoberoi

[aoberoi]

fixed!

cc @BridgeAR, @Trott, @lpinca

[BridgeAR]

Suggested change

	'Object', superCtor.prototype);
	['Object', 'Function'], superCtor.prototype);

ECMAScript does not distinguish objects and functions but users do. Both will be accepted and all other inputs (besides null) throw.

I personally would either say we should remove the check to align the error message with the one for primitives or we should check for those as well. However, that would be semver-major and this function is already deprecated, so there's probably not much point in doing this.

[aoberoi]

@BridgeAR thanks for the review! i'm excited to land a commit 😄

I don't agree with the suggested change because the value of superCtor.prototype must be an object. Sure, a function is an object so that works, but its not the function-ness of this value that is important, it is the object-ness (the intention is that this value's properties become available in the prototype chain, that's an object-y aspect of this value). I could apply your reasoning here and say that the suggested change should include Array, RegExp, etc, since they are also all objects and are equally meaningful here as Function, but I think you see that it wouldn't make the error any more meaningful to include those.

Also, I'm not sure which function you mean is deprecated. From the public docs, I don't see any deprecation for util.inherits(). Do you mean that ERR_INVALID_ARG_TYPE() is deprecated? If so, what is the more favorable alternative?

Thanks for your help!

[aoberoi]

Ping @Trott

[Trott]

CI: https://ci.nodejs.org/job/node-test-pull-request/19926/

[aoberoi]

I see a couple build errors, but I don't think they are related to this change. Those seem to both be related to Worker Threads. Are they known to be flaky?

Possibly related: #21246

[Trott]

Resume Build CI: https://ci.nodejs.org/job/node-test-pull-request/19927/ ✅

[addaleax]

Ping @BridgeAR

[addaleax]

Landed in eb5aab2, thanks for the PR!