refactoring and tests

website/src/lib/components/map/layer-control/utils.test.ts

@@ -0,0 +1,74 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
+import type { LayerTreeType } from '$lib/assets/layers';
+import { anySelectedLayer, getLayers, isSelected, remove, removeAll, toggle } from './utils';
+
+// roads: bike (selected), foot
+// satellite: esri, ign: fr (selected)
+// osm
+const tree = (): LayerTreeType => ({
+    roads: { bike: true, foot: false },
+    satellite: { esri: false, ign: { fr: true } },
+    osm: false,
+});
+
+describe('layer trees', () => {
+    it('tells if a layer is selected', () => {
+        assert.equal(isSelected(tree(), 'bike'), true);
+        assert.equal(isSelected(tree(), 'foot'), false);
+        assert.equal(isSelected(tree(), 'fr'), true);
+        assert.equal(isSelected(tree(), 'osm'), false);
+        assert.equal(isSelected(tree(), 'unknown'), false);
+    });
+
+    it('tells if anything is selected in a branch', () => {
+        const t = tree();
+        assert.equal(anySelectedLayer(t), true);
+        assert.equal(anySelectedLayer(t.roads as LayerTreeType), true);
+        assert.equal(anySelectedLayer(t.satellite as LayerTreeType), true);
+        assert.equal(anySelectedLayer({ a: false, b: { c: false } }), false);
+        assert.equal(anySelectedLayer({}), false);
+    });
+
+    it('flattens the layers of the leaves', () => {
+        assert.deepEqual(getLayers(tree()), {
+            bike: true,
+            foot: false,
+            esri: false,
+            fr: true,
+            osm: false,
+        });
+        assert.deepEqual(getLayers({}), {});
+    });
+
+    it('toggles a layer wherever it is', () => {
+        const t = toggle(tree(), 'fr');
+        assert.equal(isSelected(t, 'fr'), false);
+        assert.equal(isSelected(toggle(t, 'osm'), 'osm'), true);
+        assert.equal(isSelected(toggle(t, 'osm'), 'bike'), true);
+        // the tree is edited, and returned
+        const own = tree();
+        assert.equal(toggle(own, 'foot'), own);
+        assert.equal((own.roads as LayerTreeType).foot, true);
+        // an id that is not there changes nothing
+        assert.deepEqual(toggle(tree(), 'unknown'), tree());
+    });
+
+    it('removes layers and branches', () => {
+        assert.deepEqual(remove(tree(), 'bike'), {
+            roads: { foot: false },
+            satellite: { esri: false, ign: { fr: true } },
+            osm: false,
+        });
+        assert.deepEqual(remove(tree(), 'ign'), {
+            roads: { bike: true, foot: false },
+            satellite: { esri: false },
+            osm: false,
+        });
+        assert.deepEqual(removeAll(tree(), ['bike', 'fr', 'osm']), {
+            roads: { foot: false },
+            satellite: { esri: false, ign: {} },
+        });
+        assert.deepEqual(removeAll(tree(), []), tree());
+    });
+});