grafana/public/app/plugins/datasource/prometheus/legend.test.ts

import { renderLegendFormat } from './legend';

describe('renderLegendFormat()', () => {
  const labels = {
    a: 'AAA',
    b: 'BBB',
    'with space': 'CCC',
  };

  it('works without any labels', () => {
    expect(renderLegendFormat('hello', {})).toEqual('hello');
    expect(renderLegendFormat('hello', labels)).toEqual('hello');
  });

  it('Simple replace', () => {
    expect(renderLegendFormat('value: {{a}}', labels)).toEqual('value: AAA');
    expect(renderLegendFormat('{{a}} {{with space}}', labels)).toEqual('AAA CCC');

    // not sure if this is expected... but current behavior
    expect(renderLegendFormat('{{ a }}', labels)).toEqual('AAA');
  });

  it('Bad syntax', () => {
    expect(renderLegendFormat('value: {{a}', labels)).toEqual('value: {{a}');
    expect(renderLegendFormat('value: {a}}}', labels)).toEqual('value: {a}}}');

    // Current behavior -- not sure if expected or not
    expect(renderLegendFormat('value: {{{a}}}', labels)).toEqual('value: {a}');
  });
});