add getNativeURL function and related tests; refactor buildUrl to use native URL constructor

Author: rgaignault

packages/core/src/tools/utils/urlPolyfill.spec.ts

@@ -1,4 +1,4 @@
-import { buildUrl, getPathName, isValidUrl, normalizeUrl } from './urlPolyfill'
+import { buildUrl, getPathName, isValidUrl, normalizeUrl, getNativeURL } from './urlPolyfill'
 
 describe('normalize url', () => {
   it('should resolve absolute paths', () => {
@@ -79,3 +79,51 @@ describe('buildUrl', () => {
     expect(['file:///bar', 'file://foo.com/bar']).toContain(buildUrl('/bar', 'file://foo.com/faa').href)
   })
 })
+
+describe('getNativeURLFromIframe', () => {
+  it('should get native URL constructor from iframe', () => {
+    const nativeURL = getNativeURL()
+
+    if (nativeURL) {
+      expect(typeof nativeURL).toBe('function')
+      const url = new nativeURL('http://example.com')
+      expect(url.href).toBe('http://example.com/')
+    }
+  })
+
+  it('should work even if main window URL is overridden', () => {
+    const originalURL = window.URL
+    ;(window as any).URL = function badURL() {
+      throw new Error('Bad polyfill')
+    }
+    const nativeURL = getNativeURL()
+    if (nativeURL) {
+      expect(typeof nativeURL).toBe('function')
+      const url = new nativeURL('http://example.com')
+      expect(url.href).toBe('http://example.com/')
+    }
+    ;(window as any).URL = originalURL
+  })
+
+  it('should cache the native URL constructor', () => {
+    const firstCall = getNativeURL()
+    const secondCall = getNativeURL()
+
+    expect(firstCall).toBe(secondCall)
+  })
+
+  it('should keep the same constructor and still resolve relative URLs correctly', () => {
+    const nativeURL1 = getNativeURL()
+
+    history.pushState({}, '', '/foo/')
+    const url1 = buildUrl('./bar', location.href)
+    expect(url1.href).toBe(`${location.origin}/foo/bar`)
+
+    history.pushState({}, '', '/baz/')
+    const nativeURL2 = getNativeURL()
+    expect(nativeURL2).toBe(nativeURL1)
+
+    const url2 = buildUrl('./qux', location.href)
+    expect(url2.href).toBe(`${location.origin}/baz/qux`)
+  })
+})

packages/core/src/tools/utils/urlPolyfill.ts

@@ -18,40 +18,40 @@ export function getPathName(url: string) {
 }
 
 export function buildUrl(url: string, base?: string) {
-  const supportedURL = getSupportedUrl()
-  if (supportedURL) {
-    try {
-      return base !== undefined ? new supportedURL(url, base) : new supportedURL(url)
-    } catch (error) {
-      throw new Error(`Failed to construct URL: ${String(error)} ${jsonStringify({ url, base })!}`)
-    }
-  }
-  if (base === undefined && !/:/.test(url)) {
-    throw new Error(`Invalid URL: '${url}'`)
-  }
-  let doc = document
-  const anchorElement = doc.createElement('a')
-  if (base !== undefined) {
-    doc = document.implementation.createHTMLDocument('')
-    const baseElement = doc.createElement('base')
-    baseElement.href = base
-    doc.head.appendChild(baseElement)
-    doc.body.appendChild(anchorElement)
+  const nativeURL = getNativeURL()
+  const URLConstructor = nativeURL || URL
+
+  try {
+    return base !== undefined ? new URLConstructor(url, base) : new URLConstructor(url)
+  } catch (error) {
+    throw new Error(`Failed to construct URL: ${String(error)} ${jsonStringify({ url, base })!}`)
   }
-  anchorElement.href = url
-  return anchorElement
 }
 
-const originalURL = URL
-let isURLSupported: boolean | undefined
-function getSupportedUrl(): typeof URL | undefined {
-  if (isURLSupported === undefined) {
-    try {
-      const url = new originalURL('http://test/path')
-      isURLSupported = url.href === 'http://test/path'
-    } catch {
-      isURLSupported = false
+/**
+ * Get native URL constructor from a clean iframe
+ * This avoids polyfill issues by getting the native implementation from a fresh iframe context
+ * Falls back to the original URL constructor if iframe approach fails
+ */
+let cachedNativeURL: typeof URL | undefined
+export function getNativeURL(): typeof URL | undefined {
+  if (cachedNativeURL !== undefined) {
+    return cachedNativeURL
+  }
+
+  const iframe = document.createElement('iframe')
+  document.body.appendChild(iframe)
+
+  const iframeWindow = iframe.contentWindow
+  if (iframeWindow && (iframeWindow as any).URL) {
+    const iframeURL = (iframeWindow as any).URL as typeof URL
+    const testURL = new iframeURL('http://test.com')
+    if (testURL.href === 'http://test.com/') {
+      cachedNativeURL = iframeURL
     }
   }
-  return isURLSupported ? originalURL : undefined
+
+  document.body.removeChild(iframe)
+
+  return cachedNativeURL
 }

packages/rum/src/domain/record/serialization/serializationUtils.ts

@@ -96,7 +96,7 @@ export function switchToAbsoluteUrl(cssText: string, cssHref: string | null): st
   )
 }
 
-export function makeUrlAbsolute(url: string, baseUrl: string): string {
+function makeUrlAbsolute(url: string, baseUrl: string): string {
   try {
     return buildUrl(url, baseUrl).href
   } catch {