[web] Add tests for js/components/helpers/VirtualScroll.js

1 files changed, 21 insertions, 0 deletions

diff --git a/web/src/js/__tests__/components/helpers/VirtualScrollSpec.js b/web/src/js/__tests__/components/helpers/VirtualScrollSpec.js
new file mode 100644
index 00000000..8081e90d
--- /dev/null
+++ b/web/src/js/__tests__/components/helpers/VirtualScrollSpec.js
@@ -0,0 +1,21 @@
+import { calcVScroll } from '../../../components/helpers/VirtualScroll'
+
+describe('VirtualScroll', () => {
+
+    it('should return default state without options', () => {
+        expect(calcVScroll()).toEqual({start: 0, end: 0, paddingTop: 0, paddingBottom: 0})
+    })
+
+    it('should calculate position without itemHeights', () => {
+        expect(calcVScroll({itemCount: 0, rowHeight: 32, viewportHeight: 400, viewportTop: 0})).toEqual({
+            start: 0, end: 0, paddingTop: 0, paddingBottom: 0
+        })
+    })
+
+    it('should calculate position with itemHeights', () => {
+        expect(calcVScroll({itemCount: 5, itemHeights: [100, 100, 100, 100, 100],
+            viewportHeight: 300, viewportTop: 0})).toEqual({
+            start: 0, end: 4, paddingTop: 0, paddingBottom: 100
+        })
+    })
+})