Prometheus unit test histogram

Question

Hi I'm trying to write an alert and some unit tests for a histogram with response times. However I am not able to pass the test. Not sure if the expr is incorrect or the way I generate the data for the test.

I have the following alert exp:

- alert: InstanceDown
    expr: histogram_quantile(0.5 sum(rate(http_latency_bucket[5m])) by(le)) > 1000
    for: 5m
    labels:
        severity: page
    annotations:
        summary: "Instance {{ $labels.instance }} down"
        description: "{{ $labels.instance }} of job {{ $labels.job }} has been down for more than 5 minutes."

And the following test:

evaluation_interval: 1m
tests:
    # Test 1.
    - interval: 1m
      # Series data.
      input_series:
          - series: 'http_latency_bucket{le="100"}'
            values: '0+0x15'
          - series: 'http_latency_bucket{le="1200"}'
            values: '1+0x15'
          - series: 'http_latency_bucket{le="+Inf"}'
            values: '1+0x15'

I would expect the mean latency to be higher than 1000 with the input series. However, the test fails.