Include raw actual and expected objects in AssertionError

[ArtemGovorov]

We support AVA in wallaby.js and have a few custom renderers for displaying assertions diffs in various editors, like:

VS Code:

WebStorm:

Wallaby App:

Other testing frameworks that we support (also various assertion libs, such as chai) pass raw actual and expected objects with their assertion errors, so we (and other custom reporters) are able to display custom diffs.

AVA's new coloured ANSI diff display is great, but in order to display diffs outside of the ANSI supporting viewer (such as in the cases listed above), it would be great if the AssertionError contained raw actual and expected objects, so that a customer reporter integrated with AVA could use them for doing custom diffs/reporting (the screenshots above show how it'd look like once the PR is landed and published in AVA).

The pull request implements passing the raw actual and expected objects to the AssertionError constructor.

[novemberborn]

The pull request implements passing the raw actual and expected objects to the AssertionError constructor.

How does Wallaby access these properties? AssertionError is serialized so anything that isn't JSON will get lost as the test results make their way to the main AVA process.

[ArtemGovorov]

@novemberborn Wallaby doesn't use AVA process. We create an instance of the ava/lib/runner class and use it to run tests in our own process(es). To get the test result we patch addTestResult and get the result.assertError.

[novemberborn]

Wallaby doesn't use AVA process. We create an instance of the ava/lib/runner class and use it to run tests in our own process(es).

Aha! This should be fine then.

Let's store the values in a AssertionError#raw property (and pass a raw argument to the constructor). It'd help if you could add a code comment saying Wallaby uses this value since it manages AVA worker processes directly, lest we forget and remove it due to being unused.

[ArtemGovorov]

@novemberborn Great, thanks. Made the requested changes and left the comment (new tests should also help not to remove the property accidentally).

[novemberborn]

new tests should also help not to remove the property accidentally

You'd be surprised what I remove, especially if AVA itself doesn't use it 😉

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As you're probably aware Wallaby is using internal APIs here. There isn't much overhead in tracking these values so we're happy to help, but it all might still break in the next release.

[novemberborn]

Apologies, I meant passing raw as a property in opts.

[ArtemGovorov]

@novemberborn Fair enough, thanks for your help! Yep, we are aware that we are using AVA's internal APIs and things get broken sometimes, but thankfully our AVA users report them fairly quickly. Made the requested change.

[novemberborn]

Thanks @ArtemGovorov!