Improve failure output

[sindresorhus]

With the following:

'use strict';
module.exports = function () {
    throw new Error('foo');
};

import test from 'ava';
import fn from './';

test('unicorn', t => {
    t.true(fn());
});

test('rainbow', t => {
    t.fail();
});

I get the following using the default reporter:

The current output is a bit messy and ambiguous. For example the stack trace indent is different for the two lines.

I've done a quick mockup of what I'd like it to look like:

Note that I reduced the indent of 2 failed from 3 to 2 spaces. And I changed failed with "foo" to Error: foo to make it clear it failed with an error and what type of error. Could be a ReferenceError for example which would be lost in the previous output.

Happy to improve upon it. I want our failure output to be as readable as possible.

Here's what I used to generate the mockup:

const chalk = require('chalk');

console.log(`
  ${chalk.red('2 failed')}

  unicorn
  ${chalk.red('Error: foo')}
   ${chalk.dim('module.exports (index.js:3:8)')}
   ${chalk.dim('Test.fn (test.js:5:9)')}

  rainbow
  ${chalk.red('Test failed via t.fail()')}
   ${chalk.dim('Test.fn (test.js:9:4)')}`);

Thoughts?

Is there a way we could improve the Test.fn name in the stack trace?

Should we place the filename:line:column first? Usually the function name isn't very useful, so it's usually the line:column you care about.

[jamestalmage]

Should we place the filename:line:column first? Usually the function name isn't very useful, so it's usually the line:column you care about.

The main advantage of the current output is that it remains a valid stack trace. The only difference is that paths are relative to the basedir instead of absolute, and we filter some irrelevant ones. I think there are some advantages to keeping to the standard, namely for external tooling (WebStorm provides clickable stack traces).

[jamestalmage]

Meh - scratch that, we also remove the leading at from each line. That is probably enough to break any stack trace regexp out there (I just tested, WebStorm doesn't linkify our stuff). Let's just do whatever looks best.

[sotojuan]

Working on this—looks good to me.

[jamestalmage]

Could we do this to make stack trace clickable in iTerm2?

[sindresorhus]

@jamestalmage Yes, I was thinking the same. We should definitely do that.

[sotojuan]

BTW are we doing this for the type of errors shown or also the ones under knownFailureCount and rejectionCount/exceptionCount?

[sindresorhus]

@sotojuan Yes, if they have output, they should be in this style.

[sindresorhus]

I now noticed that the verbose reporter (ava --verbose) is also quite messy. We should fix that one too. Maybe we could even share some code between them. The output below 1 test failed should be exactly the same as the mini reporter.

[novemberborn]

These areas have undergone lots of changes. The output is now a lot better and consistent between the mini and verbose reporters: