errors: minor (SystemError) refactoring

[BridgeAR]

Checklist

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

[BridgeAR]

CI https://ci.nodejs.org/job/node-test-pull-request/14531/

[jasnell]

FWIW, This is not really a duplicated default. This is there to catch the possibility of something like new SystemError('foo', null), which is not handled by the default argument.

[addaleax]

In that case we could still remove the default argument in the parameter list, right?

[joyeecheung]

The current way SystemErrors are instantiated in the code base warrants that context would at least be a {}, theoretically we don't even need to handle the default argument if we are being careful with new SystemErrors.

[Trott]

-1 to fast-tracking.

The edge case @jasnell describes likely warrants a test case.

[BridgeAR]

I pushed another commit to remove the default values completely. They were not used at the moment. I also removed spread arguments that were unnecessary and was able to remove the default arguments in message. I renamed that function to getMessage to make clear that it is actually a function and a getter.

It is actually better not to have any default values for SystemError because that way we will detect faulty implementations early.

I also inlined a function that was only there to generate the message for SystemErrors and I found some dead code in a test. I kept it there because it seems to mirror some internal functionality.

Removed due to the changed code. PTAL

[BridgeAR]

@joyeecheung @jasnell @addaleax PTAL

[BridgeAR]

CI https://ci.nodejs.org/job/node-test-pull-request/14540/
CI https://ci.nodejs.org/job/node-test-pull-request/14541/

[BridgeAR]

Rebased due to conflicts.

New CI https://ci.nodejs.org/job/node-test-pull-request/14583/

[BridgeAR]

Landed in 109cfa1

[nelsonlarocca]

From: Ruben Bridgewater <notifications@github.com> Sent: Monday, April 30, 2018 7:56 AM To: nodejs/node <node@noreply.github.com> Cc: Subscribed <subscribed@noreply.github.com> Subject: Re: [nodejs/node] errors: minor (SystemError) refactoring (#20337) Closed #20337<#20337>. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#20337 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AcvRBOPkqCP_vmbRxAxvj8EZn5JKNRWFks5ttyYQgaJpZM4TmPtq>.