WP-API Backbone Client: buildModelGetter fails to reject deferred on fetch error

[westonruter]

I found an issue where the promise returned by getAuthorUser never resolves in the case of a request error (such as a 404). I found that the client is only accounting for the success case in which the deferred is resolved, but it is not accounting for the error case in which the deferred is just left pending.

[westonruter]

@adamsilverstein I made this 39314.0.diff​ patch off of wp-api.js, though I know it's a compiled file. I know you'll know how to apply it.

Also, any other cases of fetch being done in the Backbone client should also ensure that there is a rejection of the deferred in the case of an error as seen in this patch.

[westonruter]

I went ahead and opened a PR: ​https://github.com/WP-API/client-js/pull/149

[adamsilverstein]

Thanks @westonruter - good catch! I went ahead and added an error handler for the other get helper builder and a unit test to confirm the behavior for getAuthorUser in ​https://github.com/WP-API/client-js/pull/150 (​diff). Ultimately I would like to expand the unit test to cover all helpers. I confirmed the test I wrote fails before your patch and passes after it. I will add the test to my patch on #39264 when I get these tests into core.

[adamsilverstein]

In 39314.diff​ :

Ensure that when a helper method's underlying fetch call fails, reject gets called on the promise returned by the helper method. Enables better error handling.

[adamsilverstein]

@westonruter can you please give 39314.diff​ a review/commit?

[rachelbaker]

@adamsilverstein What do you want to do here? If @westonruter doesn't have the bandwidth to review, is there someone else? Or do you want to punt this to 4.7.2?

[adamsilverstein]

@rachelbaker I can commit to trunk, I think I need a review from a permanent committer to merge to 4.7.1

[westonruter]

@adamsilverstein I can confirm the patch works as expected.

[rachelbaker]

pinking shears

[rachelbaker]

@adamsilverstein Patch looks good. I just trimmed some extra line breaks in 39314.2.diff​ for a cleaner diff.

[adamsilverstein]

In 39680:

REST API: Add error handling for fetch error in buildModelGetter of wp-api.js.

When a call to a model getter method fails, reject the returned deferred object. Enables better handling of fetch errors.

Props westonruter, adamsilverstein.
Fixes #39314.

[dd32]

In 39682:

REST API: Add error handling for fetch error in buildModelGetter of wp-api.js.

When a call to a model getter method fails, reject the returned deferred object. Enables better handling of fetch errors.

Props westonruter, adamsilverstein.
Merges [39680] to the 4.7 branch.
Fixes #39314.