Simplify failure output - fixes #1072

[LasaleFamine]

The idea is to check when the test.error.source.file is NOT the same of the test.file within the forEach of the errors.

I saw that when I throw an error from another module the test.file refers to the module's file and not the file that is running the test.

In this case for example if I make this check, I'm able to hide the stack trace.

  1 failed

  lol.js:2

   1: const testing = () => { 
   2:   throw new Error('lol')
   3: }                       

  Error: lol

  testing (lol.js:2:8)
  Test.t [as fn] (test.js:5:2)

Waiting for your feedback to move forward!

[novemberborn]

I saw that when I throw an error from another module the test.file refers to the module's file and not the file that is running the test.

To clarify, you mean test.error.source.file refers to the module's file?

---

Your current approach means no stack traces are ever shown for errors that come out of the test file. I think that's an issue since users may write helper functions in the test file itself.

Instead we should not output the stack when it only contains one line. So this should show the stack trace:

const testing = () => {
  throw new Error('lol')
}

test('testing', t => {
  testing()
})

But this should not:

test('another test', t => {
  throw new Error('lolol')
})

That's my interpretation of @sindresorhus' comment #1072 (comment).

[LasaleFamine]

To clarify, you mean test.error.source.file refers to the module's file?

I this case (that will produce mi first post output), test.error.source.file === 'lol.js' but test.file === 'test.js':

// test.js
import test from 'ava'
import fn from './lol'

test('asd', t => {
    fn()
})

// lol.js
module.exports.testing = () => {
    throw new Error('lol')
}

I understood your point, actually initially I was thinking to check if the extracted stack trace was only one line, but I didn't know if that single line could contain some other info.
I can proceed in this way if you agree.

[novemberborn]

I understood your point, actually initially I was thinking to check if the extracted stack trace was only one line, but I didn't know if that single line could contain some other info.
I can proceed in this way if you agree.

Yes I think that's the way to go.

[LasaleFamine]

Can I assume that there aren't \n chars within the extracted stack?

Ex:

// lib/reporters/mini.js finish(runStatus)

// Check also if the stack isn't only the `test Fn` (actually check for one-line stack)
if (test.error.stack && extractStack(test.error.stack).search('\n') > -1) {
       status += '\n' + indentString(colors.errorStack(extractStack(test.error.stack)), 2);
}

Actually I don't like so much this solution because I'm calling twice the same function and I really need the comment to explain what I'm doing.
Do you have a better/correct solution for the problem?

[novemberborn]

Actually I don't like so much this solution because I'm calling twice the same function and I really need the comment to explain what I'm doing.

You could assign the stack to a variable:

if (test.error.stack) {
  const extracted = extractStack(test.error.stack);
  if (extracted.includes('\n')) {
    status += '\n' + indentString(colors.errorStack(extracted), 2);
  }
}

[LasaleFamine]

I have made the change and also added the check to the verbose reporter. Also test fixed.
Let me know if I need to change something.

[novemberborn]

This is the output for the examples I posted in #1234 (comment). Looks good to me! @sindresorhus?

[sindresorhus]

Looks great! Thank you @LasaleFamine :)