feat(cli/js/testing): Add TestDefinition::skip

[nayeemrmn]

Closes #4098.

OUTDATED EXAMPLE: shorthands no longer support skip.
test.ts:

Deno.test({ name: "some test", fn() {
  console.log(1);
} });

Deno.test({ name: "some skipped test", skip: true, fn() {
  console.log(2);
} });

Deno.test("some skipped test (shorthand)", function abc() {
  console.log(3);
}, { skip: true });

Deno.test(function someSkippedTestShorthand2() {
  console.log(4);
}, { skip: true });

cargo run -- test test.ts:

cc @bartlomieju

[bartlomieju]

@nayeemrmn looks ok, but I'm a bit hesitant to change Deno.test() signature right now

[bartlomieju]

LGTM, but let's wait for @ry's opinion before landing

(It's fine to land this one before #4371)

[bartlomieju]

We should probably collapse all of little interfaces and enums for testing under a single namespace...

[nayeemrmn]

Just realised these are all implicitly public via TestReporter in RunTestsOptions so that would be necessary. The TestEvent* stuff can and should be hidden IMO with some restructuring. All that needs to be public is TestReporter, TestResult, TestStatus and TestStats each with no references to any other proprietary type.

EDIT: Actually TestEvent{Start,Result,End} are necessary to keep TestReporter simple and extensible, but not TestEvent.

[nayeemrmn]

How is this?

namespace tests {
  export interface Result {
    name: string;
    status: "passed" | "failed" | "skipped";
    duration?: number;
    error?: Error;
  }

  export interface Stats {
    filtered: number;
    ignored: number;
    measured: number;
    passed: number;
    failed: number;
  }

  export interface StartEvent {
    tests: Deno.TestDefinition[];
  }

  export interface ResultEvent {
    result: Result;
  }

  export interface EndEvent {
    stats: Stats;
    duration: number;
    results: Result[];
  }

  export interface Reporter {
    start(msg: StartEvent): Promise<void>;
    result(msg: ResultEvent): Promise<void>;
    end(msg: EndEvent): Promise<void>;
  }

  export class ConsoleReporter implements Reporter {
    // ...
  }
}

[bartlomieju]

@nayeemrmn I already needed to split "result" into two separate messages for #4371
We should figure this out before 1.0, but it's not actionable for this PR

[bartlomieju]

@nayeemrmn can you roll back changes to test_util? I think it will need some changes to work with skip from test definition and I'll incorporate them in #4371

[ry]

I'm fine with exposing "skip" but this PR conflicts with #4371. @bartlomieju - leaving this to you to figure out how to merge and in which order.

[cknight]

With realising that @nayeemrmn was already working on this, I also went to tackle adding skip to testing.ts. Oops! If it's of any use, my simplistic implementation can be found here: https://github.com/cknight/deno/compare/0df9823..skipDenoTest

I'll not take my changes any further as this PR seems to cover it.

[bartlomieju]

LGTM, thanks @nayeemrmn!