grafana/public/app/plugins/datasource/prometheus/specs/query_hints.test.ts

import { getQueryHints, SUM_HINT_THRESHOLD_COUNT } from '../query_hints';

describe('getQueryHints()', () => {
  it('returns no hints for no series', () => {
    expect(getQueryHints('', [])).toEqual(null);
  });

  it('returns no hints for empty series', () => {
    expect(getQueryHints('', [{ datapoints: [] }])).toEqual(null);
  });

  it('returns no hint for a monotonically decreasing series', () => {
    const series = [{ datapoints: [[23, 1000], [22, 1001]] }];
    const hints = getQueryHints('metric', series);
    expect(hints).toEqual(null);
  });

  it('returns no hint for a flat series', () => {
    const series = [{ datapoints: [[null, 1000], [23, 1001], [null, 1002], [23, 1003]] }];
    const hints = getQueryHints('metric', series);
    expect(hints).toEqual(null);
  });

  it('returns a rate hint for a monotonically increasing series', () => {
    const series = [{ datapoints: [[23, 1000], [24, 1001]] }];
    const hints = getQueryHints('metric', series);

    expect(hints!.length).toBe(1);
    expect(hints![0]).toMatchObject({
      label: 'Time series is monotonically increasing.',
      fix: {
        action: {
          type: 'ADD_RATE',
          query: 'metric',
        },
      },
    });
  });

  it('returns no rate hint for a monotonically increasing series that already has a rate', () => {
    const series = [{ datapoints: [[23, 1000], [24, 1001]] }];
    const hints = getQueryHints('rate(metric[1m])', series);
    expect(hints).toEqual(null);
  });

  it('returns a rate hint w/o action for a complex monotonically increasing series', () => {
    const series = [{ datapoints: [[23, 1000], [24, 1001]] }];
    const hints = getQueryHints('sum(metric)', series);
    expect(hints!.length).toBe(1);
    expect(hints![0].label).toContain('rate()');
    expect(hints![0].fix).toBeUndefined();
  });

  it('returns a rate hint for a monotonically increasing series with missing data', () => {
    const series = [{ datapoints: [[23, 1000], [null, 1001], [24, 1002]] }];
    const hints = getQueryHints('metric', series);
    expect(hints!.length).toBe(1);
    expect(hints![0]).toMatchObject({
      label: 'Time series is monotonically increasing.',
      fix: {
        action: {
          type: 'ADD_RATE',
          query: 'metric',
        },
      },
    });
  });

  it('returns a histogram hint for a bucket series', () => {
    const series = [{ datapoints: [[23, 1000]] }];
    const hints = getQueryHints('metric_bucket', series);
    expect(hints!.length).toBe(1);
    expect(hints![0]).toMatchObject({
      label: 'Time series has buckets, you probably wanted a histogram.',
      fix: {
        action: {
          type: 'ADD_HISTOGRAM_QUANTILE',
          query: 'metric_bucket',
        },
      },
    });
  });

  it('returns a sum hint when many time series results are returned for a simple metric', () => {
    const seriesCount = SUM_HINT_THRESHOLD_COUNT;
    const series = Array.from({ length: seriesCount }, _ => ({
      datapoints: [[0, 0], [0, 0]],
    }));
    const hints = getQueryHints('metric', series);
    expect(hints!.length).toBe(1);
    expect(hints![0]).toMatchObject({
      type: 'ADD_SUM',
      label: 'Many time series results returned.',
      fix: {
        label: 'Consider aggregating with sum().',
        action: {
          type: 'ADD_SUM',
          query: 'metric',
          preventSubmit: true,
        },
      },
    });
  });
});