test: header-links icons should be unique (#777)

Co-authored-by: Noam Gaash <noam.gaash@gmail.com>

tests/mainHeader.spec.ts

@@ -0,0 +1,18 @@
+import { test, expect } from './utils'
+
+test.beforeEach(async ({ page }) => {
+  await page.goto('/')
+})
+
+test("the main header doesn't show duplicate icons", async ({ page }) => {
+  const headerLocator = page.locator('div.header-links')
+  const svgLocators = headerLocator.locator('svg')
+  const svgCount = await svgLocators.count()
+  const svgInnerHTML = []
+  for (let i = 0; i < svgCount; i++) {
+    const innerHTML = await svgLocators.nth(i).innerHTML()
+    svgInnerHTML.push(innerHTML)
+  }
+  const svgCountWithoutDuplicates = new Set(svgInnerHTML).size
+  expect(svgCountWithoutDuplicates).toBe(svgCount)
+})