Breaking changes v13 - labels as arguments considered as object

[nirapx]

Hi,
When I'm setting labels as arguments and the first argument is an array:

someCounter.labels(arr, string1, string2)

it is considered as an object and throws Added label "0" is not included in initial labelset.
I found that there is a condition if (typeof args[0] === 'object') but it might also check that it is not an array.

I've upgraded from v12 to v14 (but it happens in v13 also).

Thanks

[zbjornson]

I don't think I understand what the use case and expectation are here. metric.labels() is supposed to accept an object of key-value pairs, or a series of strings that match up one-to-one with the metric's label names. An array shouldn't be passed here. Can you clarify please?

[nirapx]

Yes.
When we used this library in v12 we could pass just arguments such as metric.labels(arg1, arg2, arg3).
One of the args was an array: metrics.labels(arr, arg2, arg3).
After upgrading to v13/14 the ability to pass an object was added also and as a result, the code above was broken.

The new code checks if the type of the first argument is an object but it returns true for array also.

[jdmarshall]

From discussion elsewhere, we seem to have implemented a number of features that make it difficult to backpedal on this change.