New --unified-diff flag makes expected/actual easier to read without colors

[rprieto]

As suggested in this issue: #702

For example, take this test:

var a = { name: 'joe',  age: 30, address: {city: 'new york', country: 'us' }};
var b = { name: 'joel', age: 30, address: {city: 'new york', country: 'usa'}};
a.should.eql(b);

mocha

mocha -C (or looking at text-only logs)

mocha --unified-diff

mocha --unified-diff -C (or looking at text-only logs)

It's my first contrib to Mocha, so another pair of eyes would be helpful.
But hopefully this will make troubleshooting tests easier!

[theleoborges]

+1;
I run my tests from a TextMate bundle -with no colours enabled- and the output is pretty confusing.
This addition would be a great improvement.

[tj]

this could be if (program.unifiedDiff) <stuff>

[rprieto]

Thanks I didn't know about that, I'll make the change.

[tj]

I almost think we should just remove the flag and make the + / - default, but ditch the rest of the unified diff output since that's not too useful here

[rprieto]

Would it be the other way around, with a flag for inline diffs?

Ditching the top/bottom part of the unified diff makes sense, I'll have a look at that later today. We could keep the 3 line context though, it helps knowing where the diff is.

[rprieto]

A few more fixes:

• +/- diff is the default
• removed useless parts of the unified diff
• new --inline-diff flag to force the old behaviour
• and I had accidentally broken escaping of invisible characters... should be fixed now

Maybe this could use actual unit tests - for now it's a set of "failing" assertions we need to run & check if the output looks OK.

[bitwiseman]

This is very cool.

Could you could rebase to collapse some of these commits together? Especially, the last six or so.
And yeah, unit tests would be nice too. I've got an error case script in #860. I don't think that will quite cover this, but you could use it as basis.

[rprieto]

Thanks, all rebased! I'll look at the (lack of) unit tests later this weekend.

[tj]

cool lookin good, apparently still needs a rebase, dont worry about the squash for now I'll pull it down after and tweak a couple things and merge it over as one

[faridnsh]

Any chance of this getting merged?

[travisjeffery]

💥