power-assert feedback

[sindresorhus]

Opening this just to gather some feedback about the new power-assert feature.

[sindresorhus]

test(t => {
    const foo = 'foo';
    t.ok(foo.indexOf('bar') !== -1);
    t.end();
});

t.ok(foo.indexOf('bar') !== -1)
           |
           -1

@twada Any way we could show the value of foo here too? I think that could be useful.
@vdemedes What do you think?

[Qix-]

This is badass. This might actually make me switch to Ava. 💃

[sindresorhus]

@twada

Currently this:

test(t => {
    const b = 'bar';
    const c = 'baz';
    t.is(b, c);
    t.end();
});

Outputs:

t.is(b, c)
       |  | 
       |  "baz"
       "bar"

Is there any way to have it output the old simple output when using direct inputs? Meaning no expressions.

Old simple output:

'bar' === 'baz'

That output is faster to look at.

[sindresorhus]

@twada @uiureo I've documented the enhanced asserts. Would appriciate your review. Happy to change anything. 89219ce?short_path=0730bb7#diff-0730bb7c2e8f9ea2438b52e419dd86c9 :)

[vadimdemedes]

This is fucking amazing.

@sindresorhus, agree on the simple output, looks way better!

[twada]

First, as an author of power-assert, I'm so glad to see this happen! 😄
Thank you @sindresorhus !

@twada @uiureo I've documented the enhanced asserts. Would appriciate your review. Happy to change anything. 89219ce?short_path=0730bb7#diff-0730bb7c2e8f9ea2438b52e419dd86c9 :)

I think it's well written.

[twada]

@sindresorhus

t.ok(foo.indexOf('bar') !== -1)
         |
         -1

@twada Any way we could show the value of foo here too? I think that could be useful.

AVA's power-assert output is configured at ava/enhance-assert.js (see renderers section)

If you change powerAssertRenderers.SuccinctRenderer to powerAssertRenderers.DiagramRenderer like below,

    empower(assert,
        powerAssertFormatter({
            renderers: [
                powerAssertRenderers.AssertionRenderer,
                powerAssertRenderers.DiagramRenderer
            ]
        }),
        {
            destructive: true,
            modifyMessageOnRethrow: true,
            saveContextOnRethrow: false,
            patterns: module.exports.PATTERNS
        }
    );

You'll get verbose output like

t.ok(foo.indexOf('bar') !== -1)
     |   |              |
     |   |              |
     |   -1             false
     ["toto", "tata", "titi"]

It seems nice to have verbosity configuration options in AVA, and change power-assert renderers according to the option value.

[sindresorhus]

I know I'm asking a lot, but I would like the following not to use power-assert, since it's just direct input.

test(t => {
    const b = 'bar';
    const c = 'baz';
    t.is(b, c);
    t.end();
});

But this should use power-assert since it's an expression and could benefit from the power-assert output.

test(t => {
    const b = 'bar';
    const c = 'baz';
    const d = 'faz';
    t.is(b + d, c);
    t.end();
});

[twada]

@sindresorhus

Is there any way to have it output the old simple output when using direct inputs? Meaning no expressions.

Currently, t.is is configured to be enhanced by power-assert and power-assert cannot toggle output on and off by captured value for now.

What you mean here is that if two arguments are both in form of Identifier or Literal, and its values are simple primitives, AVA's power-assert feature should be turned off automatically. It is not possible now but worth challenging.

[twada]

@sindresorhus

Oh I missed your next question!

But this should use power-assert since it's an expression and could benefit from the power-assert output.

test(t => {
    const b = 'bar';
    const c = 'baz';
    const d = 'faz';
    t.is(b + d, c);
    t.end();
});

Thank you for your clear example!
My answer is the same as former one --- It's not possible now, but I'll try to make it happen.

[sindresorhus]

It wouldn't nessecarily have to be turned off, could maybe just change the renderer to not show diagrams when Identifier or Literal is passed. This is just a nitpick/nicetohave, though.

[twada]

@sindresorhus Thanks, it's getting a bit easier.

[vadimdemedes]

@twada is babel-plugin-espower compatible with babel 6?

[twada]

@vdemedes Not yet. I'm wrestling with Babel6 now.
Almost done but still doesn't work with presets.

[SamVerschueren]

Not sure if I should create a new issue for this, but when using promises (await statements), power-assert does not show the correct value.

t.same(await fn(fixture1), {})
             |
             Object{}

The result of the promise is not empty, that's for sure :).

---

Seems I was too fast on this one. Apparently, the object shown underneath is the same as the second argument of the assert, which is not the actual result.

t.same(await fn(fixture1), {foo: 'bar'})
             |
             Object{foo: "bar"}

[twada]

@SamVerschueren Thank you for reporting!
Currently, power-assert only supports ES6/ES2015 expressions. So AwaitExpression is not supported yet and to be supported in next version. BTW, I'll take a look about this behavior.

[SamVerschueren]

Thanks for the feedback!

[sindresorhus]

@SamVerschueren Looks like #113.

[SamVerschueren]

Sorry, should have looked in the issue list first.

[twada]

@SamVerschueren No problem!

[jamestalmage]

@SamVerschueren - async/await fix is in master.

[SamVerschueren]

Awesome! 👍

[novemberborn]

@sindresorhus is there any more feedback you're looking to collect in this issue, or shall we close it?

[sindresorhus]

Yup, can be closed in favor of twada/power-assert-renderers#3.