add tests for irate #107

Job	Run time
Check generated parser	12s
Build Prometheus for common architectures (0)	7m 0s
fuzzing	0s
Build Prometheus for all architectures	0s
Build Prometheus for common architectures (1)	7m 7s
golangci-lint	36s
Build Prometheus for common architectures (2)	7m 13s
Go tests	17m 17s
More Go tests	5m 48s
Go tests with previous Go version	8m 56s
Mixins tests	2m 22s
UI tests	2m 12s
Go tests on Windows	12m 39s
codeql / Analyze (javascript)	1m 42s
Report status of build Prometheus for all architectures	0s
Publish UI on npm Registry	1m 42s
Publish main branch artifacts	0s
Publish release artefacts	0s
	1h 14m 46s

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