Asserting on metrics in Tests

[cpaika]

Sometimes while writing unit/integration tests you may want to assert on certain metrics being set - for example, you send a few HTTP queries and assert the metrics are being incremented correctly.

If I have a metrics object, I can access counters but I can't seem to get the actual underlying value of the counter as a i64/u64/etc to be able to assert it has a specific value. Is there a way to do this I'm missing? If not can it be tracked as a feature request?

[utpilla]

For Counters, you could downcast data field of the Metric struct to a Sum struct which would give you access to the actual values from Vec<DataPoints>.

You could reference the code in stdout exporter. It does the same kind of data transformations to print out the metric values.

[cpaika]

Awesome, thank you!