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

/**
 * The module that ends the stranding: before it, a school page's only anchor
 * pointed at the school's own website, so ~27k pages sent authority off-site
 * and none of it reached the location layer.
 */
import { render, screen } from '@testing-library/react';
import { NearbyPlaces } from '@/components/school/NearbyPlaces';

const essex = { kind: 'authority', slug: 'essex', name: 'Essex', count: 480, url: '/schools/authority/essex', phases: [] };
const brentwood = { kind: 'town', slug: 'brentwood', name: 'Brentwood', count: 37, url: '/schools/brentwood', phases: [] };
const cm15 = { kind: 'outcode', slug: 'cm15', name: 'CM15', count: 12, url: '/schools/near/cm15', phases: [] };

describe('NearbyPlaces', () => {
  it('links to every place the school belongs to', () => {
    render(<NearbyPlaces places={[essex, brentwood, cm15]} />);

    expect(screen.getByRole('link', { name: /Brentwood/ }))
      .toHaveAttribute('href', '/schools/brentwood');
    expect(screen.getByRole('link', { name: /Essex/ }))
      .toHaveAttribute('href', '/schools/authority/essex');
    expect(screen.getByRole('link', { name: /CM15/ }))
      .toHaveAttribute('href', '/schools/near/cm15');
  });

  it('says how many schools each link leads to', () => {
    // An anchor that states its destination's size is worth more to a reader
    // and to a crawler than "see more".
    render(<NearbyPlaces places={[brentwood]} />);
    expect(screen.getByRole('link', { name: /37 schools in Brentwood/ }))
      .toBeInTheDocument();
  });

  it('renders nothing at all when the school has no published places', () => {
    // Not an empty heading. A school whose town and authority both fall below
    // the threshold has nowhere to point, and the page should look as it did
    // before the module existed.
    const { container } = render(<NearbyPlaces places={[]} />);
    expect(container).toBeEmptyDOMElement();
  });

  it('puts the narrowest place first, which is the most useful link', () => {
    // The API orders widest-first for the breadcrumb; a reader on a school
    // page wants its town before its county.
    render(<NearbyPlaces places={[essex, brentwood, cm15]} />);
    const hrefs = screen.getAllByRole('link').map((a) => a.getAttribute('href'));
    expect(hrefs.indexOf('/schools/brentwood'))
      .toBeLessThan(hrefs.indexOf('/schools/authority/essex'));
  });

  it('handles a singular count without saying "1 schools"', () => {
    render(<NearbyPlaces places={[{ ...brentwood, count: 1 }]} />);
    expect(screen.getByRole('link', { name: /1 school in Brentwood/ }))
      .toBeInTheDocument();
  });

  it('links the phase page the school appears on', () => {
    // "primary schools in brentwood" is the query these pages exist for.
    render(<NearbyPlaces places={[{
      ...brentwood,
      phases: [{ phase: 'primary', count: 22, url: '/schools/brentwood/primary' }],
    }]} />);

    expect(screen.getByRole('link', { name: /22 primary schools in Brentwood/ }))
      .toHaveAttribute('href', '/schools/brentwood/primary');
  });

  it('links both phase pages for an all-through school', () => {
    render(<NearbyPlaces places={[{
      ...brentwood,
      phases: [
        { phase: 'primary', count: 22, url: '/schools/brentwood/primary' },
        { phase: 'secondary', count: 9, url: '/schools/brentwood/secondary' },
      ],
    }]} />);

    expect(screen.getByRole('link', { name: /22 primary schools/ })).toBeInTheDocument();
    expect(screen.getByRole('link', { name: /9 secondary schools/ })).toBeInTheDocument();
  });

  it('keeps a phase link next to the place it belongs to', () => {
    // Grouping matters: "22 primary schools in Brentwood" directly after
    // "37 schools in Brentwood" reads as one place, not two unrelated links.
    render(<NearbyPlaces places={[essex, {
      ...brentwood,
      phases: [{ phase: 'primary', count: 22, url: '/schools/brentwood/primary' }],
    }]} />);

    const hrefs = screen.getAllByRole('link').map((a) => a.getAttribute('href'));
    expect(hrefs.indexOf('/schools/brentwood/primary'))
      .toBe(hrefs.indexOf('/schools/brentwood') + 1);
  });
});