1 files changed, 30 insertions, 0 deletions
diff --git a/viewer/tests/hover.test.mjs b/viewer/tests/hover.test.mjs
new file mode 100644
index 0000000..7b26be5
--- /dev/null
+++ b/viewer/tests/hover.test.mjs
@@ -0,0 +1,30 @@
+import './_planet.mjs';
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { hoverText } from '../js/hover.js';
+
+const cell = fields => ({ cell: 'x', lat: 0, lon: 0, fields });
+
+test('land shows elevation and life zone', () => {
+  assert.equal(hoverText(cell([{ key: 'z_surface_m', value: 2344.4 }, { key: 'ocean', value: false, text: 'no' },
+    { key: 'lake', value: false, text: 'no' }, { key: 'holdridge', value: 3, text: 'cool temperate desert scrub' }])),
+  '2,344 m · cool temperate desert scrub');
+});
+
+test('sea shows depth; lakes are named; procedural detail only when tiles show', () => {
+  assert.equal(hoverText(cell([{ key: 'z_surface_m', value: -3300 }, { key: 'ocean', value: true, text: 'yes' }])), 'sea, 3,300 m deep');
+  assert.equal(hoverText(cell([{ key: 'z_surface_m', value: 120 }, { key: 'ocean', value: false }, { key: 'lake', value: true },
+    { key: 'holdridge', value: 1, text: 'boreal moist forest' }])), '120 m · lake · boreal moist forest');
+  const both = cell([{ key: 'z_surface_m', value: 120 }, { key: 'z_detail_m', value: 131.6 }, { key: 'ocean', value: false }]);
+  assert.equal(hoverText(both), '120 m', 'zoomed out: the build value');
+  assert.equal(hoverText(both, true), '132 m', 'procedural tiles showing: the detail value');
+});
+
+test('a cell answer is reused near its centre, never under procedural detail', async () => {
+  const { canReuse } = await import('../js/hover.js');
+  const c = { center: [10, 20], inner_km: 50 };
+  assert.equal(canReuse(c, { lat: 10.1, lon: 20 }, false), true);
+  assert.equal(canReuse(c, { lat: 11, lon: 20 }, false), false);
+  assert.equal(canReuse(c, { lat: 10.1, lon: 20 }, true), false);
+  assert.equal(canReuse(null, { lat: 10, lon: 20 }, false), false);
+});