task-stream/libs/api/tracker/application/src/lib/analytics/analytics.spec.ts

import {
  IssueReadModel,
  IssueTimelineEntry,
  ReleaseReadModel,
  ReleaseStatus,
  StatusCategory as C,
} from '@task-stream/api/tracker/domain';
import {
  computeProjectAnalytics,
  computeReleaseBurnup,
  weekOf,
} from './analytics';

const ana = { id: 'ana', name: 'Ana' };
const bob = { id: 'bob', name: 'Bob' };

const issue = (
  id: string,
  createdAt: string,
  status: string,
  category: C,
  releaseId: string | null = null,
): IssueReadModel =>
  ({
    id,
    key: id,
    createdAt,
    status,
    statusCategory: category,
    reporter: ana,
    assignee: bob,
    release: releaseId ? { id: releaseId, name: 'v1' } : null,
  }) as IssueReadModel;

let seq = 0;
const step = (
  issueId: string,
  at: string,
  status: string,
  category: C,
  assigneeId: string | null = 'bob',
): IssueTimelineEntry => ({
  id: `${issueId}:${++seq}`,
  issueId,
  projectId: 'p',
  at,
  kind: 'status',
  status,
  category,
  assigneeId,
});

/*
 * A: created Mon 5 Oct, started Tue 6, to QA Wed 7, QA failed Thu 8, back to QA and done Fri 9.
 * B: created Mon 5 Oct, started Mon 12, QA Tue 13, done Wed 14 (by Ana).
 * C: created Tue 13 Oct, still in backlog.
 */
const issues = [
  issue('A', '2026-10-05T09:00:00Z', 'DONE', C.DONE, 'rel'),
  issue('B', '2026-10-05T10:00:00Z', 'DONE', C.DONE, 'rel'),
  issue('C', '2026-10-13T10:00:00Z', 'BACKLOG', C.TODO),
];
const timeline: IssueTimelineEntry[] = [
  step('A', '2026-10-05T09:00:00Z', 'BACKLOG', C.TODO),
  {
    id: 'A:r',
    issueId: 'A',
    projectId: 'p',
    at: '2026-10-05T09:00:01Z',
    kind: 'release',
    releaseId: 'rel',
  },
  step('A', '2026-10-06T09:00:00Z', 'IN_PROGRESS', C.IN_PROGRESS),
  step('A', '2026-10-07T09:00:00Z', 'IN_QA', C.QA),
  step('A', '2026-10-08T09:00:00Z', 'QA_FAILED', C.IN_PROGRESS),
  step('A', '2026-10-09T08:00:00Z', 'IN_QA', C.QA),
  step('A', '2026-10-09T09:00:00Z', 'DONE', C.DONE),
  step('B', '2026-10-05T10:00:00Z', 'BACKLOG', C.TODO),
  {
    id: 'B:r',
    issueId: 'B',
    projectId: 'p',
    at: '2026-10-12T08:00:00Z',
    kind: 'release',
    releaseId: 'rel',
  },
  step('B', '2026-10-12T10:00:00Z', 'IN_PROGRESS', C.IN_PROGRESS),
  step('B', '2026-10-13T10:00:00Z', 'IN_QA', C.QA),
  step('B', '2026-10-14T10:00:00Z', 'DONE', C.DONE, 'ana'),
];

describe('project analytics', () => {
  const stats = computeProjectAnalytics({
    issues,
    timeline,
    statusOrder: ['BACKLOG', 'IN_PROGRESS', 'IN_QA', 'QA_FAILED', 'DONE'],
    from: new Date('2026-10-05T00:00:00Z'),
    to: new Date('2026-10-14T23:59:59Z'),
  });

  it('counts created and resolved tickets per week (Monday)', () => {
    expect(weekOf(Date.parse('2026-10-11T12:00:00Z'))).toBe('2026-10-05');
    expect(stats.createdVsResolved).toEqual([
      { week: '2026-10-05', created: 2, resolved: 1 },
      { week: '2026-10-12', created: 1, resolved: 1 },
    ]);
  });

  it('measures cycle time (start → done) and lead time (created → done)', () => {
    // A: 3 days of cycle, 4 of lead. B: 2 and 9.
    expect(stats.cycleTime).toEqual({ count: 2, averageDays: 2.5, p85Days: 3 });
    expect(stats.leadTime).toEqual({ count: 2, averageDays: 6.5, p85Days: 9 });
  });

  it('counts QA passes and failures', () => {
    expect(stats.qa).toEqual({ passed: 2, failed: 1, failureRate: 0.333 });
  });

  it('attributes throughput to who had the ticket', () => {
    expect(stats.throughput).toEqual([
      { week: '2026-10-05', user: bob, count: 1 },
      { week: '2026-10-12', user: ana, count: 1 },
    ]);
  });

  it('builds the cumulative flow day by day, in the workflow order', () => {
    const flow = stats.cumulativeFlow;
    expect(flow.dates).toHaveLength(10);
    expect(flow.series.map((s) => s.status)).toEqual([
      'BACKLOG',
      'IN_PROGRESS',
      'IN_QA',
      'QA_FAILED',
      'DONE',
    ]);
    const at = (status: string, day: string) =>
      flow.series.find((s) => s.status === status)?.counts[
        flow.dates.indexOf(day)
      ];
    expect(at('BACKLOG', '2026-10-05')).toBe(2);
    expect(at('QA_FAILED', '2026-10-08')).toBe(1);
    expect(at('DONE', '2026-10-14')).toBe(2);
    expect(at('BACKLOG', '2026-10-14')).toBe(1); // C
  });

  it('falls back to creation + current status for tickets without timeline', () => {
    const old = computeProjectAnalytics({
      issues: [issue('OLD', '2026-10-01T00:00:00Z', 'TODO', C.TODO)],
      timeline: [],
      statusOrder: [],
      from: new Date('2026-10-01T00:00:00Z'),
      to: new Date('2026-10-02T23:00:00Z'),
    });
    expect(old.cumulativeFlow.series).toEqual([
      { status: 'TODO', counts: [1, 1] },
    ]);
  });
});

describe('release burnup', () => {
  it('tracks scope and done tickets of the release per day', () => {
    const release = {
      id: 'rel',
      createdAt: '2026-10-05T08:00:00Z',
      releasedAt: '2026-10-14T18:00:00Z',
      targetDate: '2026-10-15',
      status: ReleaseStatus.RELEASED,
    } as ReleaseReadModel;
    const burnup = computeReleaseBurnup({
      release,
      issues,
      timeline,
      now: new Date('2026-10-20T00:00:00Z'),
    });
    const at = (series: number[], day: string) =>
      series[burnup.dates.indexOf(day)];
    expect(burnup.dates[0]).toBe('2026-10-05');
    expect(burnup.dates.at(-1)).toBe('2026-10-14');
    expect(at(burnup.scope, '2026-10-05')).toBe(1); // A
    expect(at(burnup.scope, '2026-10-12')).toBe(2); // + B
    expect(at(burnup.done, '2026-10-09')).toBe(1);
    expect(at(burnup.done, '2026-10-14')).toBe(2);
  });
});