LGTM

frontend/src/lib/url-state.test.ts

@@ -2,8 +2,15 @@ import { beforeEach, describe, expect, it } from 'vitest';
 
 import type { FeatureMeta } from '../types';
 import { parseUrlState, stateToParams } from './url-state';
+import { INITIAL_VIEW_STATE } from './consts';
 import { createSchoolFilterKey } from './school-filter';
 import { createSpecificCrimeFilterKey } from './crime-filter';
+import { createEthnicityFilterKey } from './ethnicity-filter';
+import {
+  POI_COUNT_2KM_FILTER_NAME,
+  createPoiDistanceFilterKey,
+  createPoiFilterKey,
+} from './poi-distance-filter';
 
 describe('url-state', () => {
   beforeEach(() => {
@@ -43,6 +50,15 @@ describe('url-state', () => {
     ]);
   });
 
+  it('leaves POIs unselected when URL params are omitted', () => {
+    const state = parseUrlState();
+
+    expect(state.viewState).toEqual(INITIAL_VIEW_STATE);
+    expect(state.filters).toEqual({});
+    expect(state.poiCategories).toEqual(new Set());
+    expect(state.tab).toBe('area');
+  });
+
   it('serializes map state and active filters into stable URL params', () => {
     const features: FeatureMeta[] = [
       { name: 'Last known price', type: 'numeric' },
@@ -81,6 +97,17 @@ describe('url-state', () => {
     expect(params.getAll('tt')).toEqual(['bicycle:bank:Bank:5:25']);
   });
 
+  it('round-trips an explicitly empty POI selection', () => {
+    const params = stateToParams(null, {}, [], new Set(), 'area');
+
+    expect(params.getAll('poi')).toEqual(['__none']);
+
+    window.history.replaceState({}, '', `/?${params.toString()}`);
+    const state = parseUrlState();
+
+    expect(state.poiCategories).toEqual(new Set());
+  });
+
   it('round-trips repeated school filters with dedicated URL params', () => {
     const schoolOne = createSchoolFilterKey('primary', 'good', 2, 1);
     const schoolTwo = createSchoolFilterKey('secondary', 'outstanding', 5, 2);
@@ -141,6 +168,91 @@ describe('url-state', () => {
     });
   });
 
+  it('round-trips repeated ethnicity filters with dedicated URL params', () => {
+    const white = createEthnicityFilterKey('% White', 3);
+    const southAsian = createEthnicityFilterKey('% South Asian', 4);
+
+    const params = stateToParams(
+      null,
+      {
+        [white]: [10, 80],
+        [southAsian]: [5, 35],
+      },
+      [],
+      new Set(),
+      'area'
+    );
+
+    expect(params.getAll('ethnicity')).toEqual(['% White:10:80', '% South Asian:5:35']);
+    expect(params.getAll('filter')).toEqual([]);
+
+    window.history.replaceState({}, '', `/?${params.toString()}`);
+    const state = parseUrlState();
+
+    expect(state.filters).toEqual({
+      [createEthnicityFilterKey('% White', 0)]: [10, 80],
+      [createEthnicityFilterKey('% South Asian', 1)]: [5, 35],
+    });
+  });
+
+  it('round-trips repeated POI distance filters with dedicated URL params', () => {
+    const park = createPoiDistanceFilterKey('Distance to nearest park (km)', 3);
+    const tesco = createPoiDistanceFilterKey('Distance to nearest Tesco (km)', 4);
+
+    const params = stateToParams(
+      null,
+      {
+        [park]: [0, 0.4],
+        [tesco]: [0, 1.5],
+      },
+      [],
+      new Set(),
+      'area'
+    );
+
+    expect(params.getAll('poiDistance')).toEqual([
+      'Distance%20to%20nearest%20park%20(km):0:0.4',
+      'Distance%20to%20nearest%20Tesco%20(km):0:1.5',
+    ]);
+    expect(params.getAll('filter')).toEqual([]);
+
+    window.history.replaceState({}, '', `/?${params.toString()}`);
+    const state = parseUrlState();
+
+    expect(state.filters).toEqual({
+      [createPoiDistanceFilterKey('Distance to nearest park (km)', 0)]: [0, 0.4],
+      [createPoiDistanceFilterKey('Distance to nearest Tesco (km)', 1)]: [0, 1.5],
+    });
+  });
+
+  it('round-trips POI count filters with dedicated URL params', () => {
+    const cafes = createPoiFilterKey(
+      POI_COUNT_2KM_FILTER_NAME,
+      'Number of Cafe POIs within 2km',
+      3
+    );
+
+    const params = stateToParams(
+      null,
+      {
+        [cafes]: [2, 8],
+      },
+      [],
+      new Set(),
+      'area'
+    );
+
+    expect(params.getAll('poiCount2km')).toEqual(['Number%20of%20Cafe%20POIs%20within%202km:2:8']);
+    expect(params.getAll('filter')).toEqual([]);
+
+    window.history.replaceState({}, '', `/?${params.toString()}`);
+    const state = parseUrlState();
+
+    expect(state.filters).toEqual({
+      [createPoiFilterKey(POI_COUNT_2KM_FILTER_NAME, 'Number of Cafe POIs within 2km', 0)]: [2, 8],
+    });
+  });
+
   it('omits the default area tab', () => {
     const params = stateToParams(null, {}, [], new Set(), 'area');