Include only plain objects/arrays in t.true/t.false output of statements

[vadimdemedes]

AVA's magic-assert output causes a crash when this kind of assertion fails:

t.true(some.spy.calledOnce);

or similar, when functions/instances are involved. This is happening, because @ava/pretty-print tries to print some.spy and some nicely. When parsing statements in lib/enhance-assert, we should ignore anything but plain objects and arrays.

[novemberborn]

Could you elaborate on what specifically causes the crash?

When parsing statements in lib/enhance-assert, we should ignore anything but plain objects and arrays.

How does this affect the output for t.true(some.spy.calledOnce)?

[vadimdemedes]

Sure. You can easily cause a crash if one of the statements contain (or is) a reference to a global scope (global). There's a ton of stuff in there and it doesn't make sense to print that.

Same goes with all the libraries. Unless it's a plain object or array, we can't pretty print it. Even if we could, why would we? The output needs to be meaningful and compact. So in the above example, t.true(some.spy.calledOnce) it's enough to print that some.spy.calledOnce is false.

[novemberborn]

Same goes with all the libraries. Unless it's a plain object or array, we can't pretty print it. Even if we could, why would we? The output needs to be meaningful and compact. So in the above example, t.true(some.spy.calledOnce) it's enough to print that some.spy.calledOnce is false.

Fair enough.

I'd love to be able to print Map and Set though. And for those values we can't print, indicate their type.

[vadimdemedes]

Sure, Map and Set are ok. Talking about instances of classes/libraries. For example, you wouldn't want to pretty print an instance of Mongoose model, right?

[novemberborn]

For example, you wouldn't want to pretty print an instance of Mongoose model, right?

It can be useful sometimes, but probably no 😄 Perhaps those kinds of instances could be restricted to showing the first three properties, with a little note saying "59 more properties not shown".

[vadimdemedes]

I think implementing this might be overly complicated and could take a while. This bug is quite annoying actually, I've seen it at least 6 times during last 2 days (yes, I've set up a counter 😄). I'd just go for a set of accepted types to be pretty-formatted in the "statements" output and push a fix. We can always make it more complex later ;)

[novemberborn]

I'd just go for a set of accepted types to be pretty-formatted in the "statements" output and push a fix. We can always make it more complex later ;)

👍

[sindresorhus]

I'd just go for a set of accepted types to be pretty-formatted in the "statements" output and push a fix. We can always make it more complex later ;)
👍

👍

[novemberborn]

@vadimdemedes do you recall the actual error? I assume you're using Sinon, but with sinon@1.17.7 I just get [Function proxy] for @ava/pretty-format output of the sinon.spy() result.

[pho3nixf1re]

This same behavior happens when using enzyme wrappers. The output is so large it makes the test output useless. I've gotten into the habit of putting the exact test value into a variable before passing it to the ava assertion.