Init metrics to zero

[siimon]

Fixing #118

Added fixes for Counters, Gauges and Histograms.. Summary I'm not sure what to do about tbh.. After a quick look it's not an easy fix.

[SimenB]

@siimon I pushed a fix for summaries, and added a snapshot test for full output.

Working on the case with labels

[siimon]

Great! Thanks! :)

[SimenB]

Ok, should be done now.

Had to revert most of the test changes when considering labels

[siimon]

LGTM!

[SimenB]

@dm3 @paulborza does this look correct? You can check the snapshot test for output with and without labels.

https://github.com/siimon/prom-client/pull/139/files#diff-23be0e4ea533e57b2bd533eaddfed48c

[paulborza]

@SimenB why initialize the metrics only when there are no labels? The metrics should be initialized to 0 across all labels.

[siimon]

How would you do that since you don't know the values for the labels? You only know the label names when you create the metric

[paulborza]

@siimon You're right; my bad. The output looks good for metrics with no labels.
Argh, I just wish there was a way Prometheus would support some sort of wildcard syntax to initialize metrics across all dimensions/labels; but apparently it doesn't.

Thanks for fixing this! :)

[paulborza]

Once merged, can you also publish the new version to the registry? Thanks

[SimenB]

Once merged, can you also publish the new version to the registry? Thanks

Of course 🙂