increase test coverage

extend test coverage

tests/e2e/unit/svgcore-namespaces.spec.js

@@ -0,0 +1,28 @@
+import { test, expect } from '../fixtures.js'
+
+test.describe('SVG namespace helpers', () => {
+  test.beforeEach(async ({ page }) => {
+    await page.goto('/tests/unit-harness.html')
+    await page.waitForFunction(() => Boolean(window.svgHarness?.namespaces))
+  })
+
+  test('reverse namespace map includes core URIs', async ({ page }) => {
+    const result = await page.evaluate(() => {
+      const { namespaces } = window.svgHarness
+      const reverse = namespaces.getReverseNS()
+      return {
+        svg: namespaces.NS.SVG,
+        html: namespaces.NS.HTML,
+        xml: namespaces.NS.XML,
+        reverseSvg: reverse[namespaces.NS.SVG],
+        reverseXmlns: reverse[namespaces.NS.XMLNS]
+      }
+    })
+
+    expect(result.svg).toBe('http://www.w3.org/2000/svg')
+    expect(result.html).toBe('http://www.w3.org/1999/xhtml')
+    expect(result.xml).toBe('http://www.w3.org/XML/1998/namespace')
+    expect(result.reverseSvg).toBe('svg')
+    expect(result.reverseXmlns).toBe('xmlns')
+  })
+})