school_compare/nextjs-app/__tests__/components/schoolPupilCount.test.tsx

/**
 * "Pupils" on a school page is the size of the school.
 *
 * A year's results row carries the cohort its figures were measured on. For a
 * secondary that is the GCSE year group alone (Burntwood: 245, against 1,462
 * on roll), so it must never stand in for the whole-school count.
 */

import { screen } from '@testing-library/react';
import { secondaryFixture } from '../support/schoolFixtures';
import { renderSecondarySchoolDetail } from '../support/renderSchoolDetail';

jest.mock('@/lib/analytics', () => ({
  track: jest.fn(),
  getNavigationSource: () => 'direct',
}));
jest.mock('@/components/PerformanceChart', () => ({
  PerformanceChart: () => <div data-testid="performance-chart" />,
}));
jest.mock('@/components/SatsChart', () => ({
  __esModule: true,
  default: () => <div data-testid="sats-chart" />,
}));
jest.mock('@/components/AdmissionsTrendChart', () => ({
  __esModule: true,
  default: () => <div data-testid="admissions-trend-chart" />,
}));
jest.mock('@/components/SchoolHeroMap', () => ({
  SchoolHeroMap: () => <div data-testid="hero-map" />,
  __esModule: true,
}));

function withoutCensus(schoolTotal: number | null) {
  const yearlyData = secondaryFixture.yearlyData.map((r) => ({ ...r, total_pupils: 245 }));
  return {
    ...secondaryFixture,
    census: null,
    yearlyData,
    schoolInfo: { ...secondaryFixture.schoolInfo, total_pupils: schoolTotal },
  };
}

describe('pupil count without a census record', () => {
  it('uses the register count in the header, not the results cohort', () => {
    renderSecondarySchoolDetail(withoutCensus(1462));
    expect(screen.getByText('1,462 pupils')).toBeInTheDocument();
    expect(screen.queryByText('245 pupils')).not.toBeInTheDocument();
  });

  it('shows no count rather than the results cohort when the register has none', () => {
    renderSecondarySchoolDetail(withoutCensus(null));
    expect(screen.queryByText(/^[\d,]+ pupils$/)).not.toBeInTheDocument();
    expect(screen.queryByText('Total pupils')).not.toBeInTheDocument();
  });
});