Create standalone browser port of LTX Athena with authenticated native API transport

frontend/lib/fixed-menu-position.test.ts

@@ -0,0 +1,66 @@
+import assert from 'node:assert/strict'
+import { describe, it } from 'node:test'
+import { fixedMenuPosition } from './fixed-menu-position.ts'
+
+const trigger = { left: 100, right: 180, top: 500, bottom: 532 }
+const viewport = { width: 1000, height: 800 }
+
+describe('fixedMenuPosition', () => {
+  it('anchors a menu above the trigger', () => {
+    const pos = fixedMenuPosition({
+      trigger,
+      placement: 'above',
+      viewport,
+      menuWidth: 160,
+      gap: 8,
+    })
+    assert.equal(pos.left, 100)
+    assert.equal(pos.bottom, 308)
+    assert.equal(pos.top, undefined)
+  })
+
+  it('anchors a menu below the trigger', () => {
+    const pos = fixedMenuPosition({
+      trigger,
+      placement: 'below',
+      viewport,
+      menuWidth: 160,
+      gap: 8,
+    })
+    assert.equal(pos.left, 100)
+    assert.equal(pos.top, 540)
+    assert.equal(pos.bottom, undefined)
+  })
+
+  it('shifts left so a wide menu stays on-screen', () => {
+    const pos = fixedMenuPosition({
+      trigger: { left: 900, right: 980, top: 500, bottom: 532 },
+      placement: 'above',
+      viewport,
+      menuWidth: 160,
+      gap: 8,
+    })
+    assert.equal(pos.left, 820)
+  })
+
+  it('does not use an assumed width when the menu has not been measured', () => {
+    const pos = fixedMenuPosition({
+      trigger: { left: 900, right: 980, top: 500, bottom: 532 },
+      placement: 'above',
+      viewport,
+      gap: 8,
+    })
+    assert.equal(pos.left, 900)
+  })
+
+  it('ignores a viewport-filling width from an unpositioned block menu', () => {
+    const pos = fixedMenuPosition({
+      trigger: { left: 400, right: 480, top: 500, bottom: 532 },
+      placement: 'above',
+      viewport,
+      menuWidth: 1000,
+      gap: 8,
+    })
+    assert.equal(pos.left, 400)
+  })
+})