Fix detection of anchor click events inside svg (vercel#23272)

## Bug

The `nodeName` of an anchor inside an SVG equals the lowercase `a` instead of the html anchor's uppercase `A`.
This behavior can be seen in this plain js demo: https://jsfiddle.net/L2p8f4ve/28/

fixes vercel#23252




## Bug

- [x] Related issues linked using `fixes #number`
- [x] Integration tests added

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.

## Documentation / Examples

- [ ] Make sure the linting passes

Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>

packages/next/client/link.tsx

@@ -86,7 +86,10 @@ function linkClicked(
 ): void {
   const { nodeName } = e.currentTarget
 
-  if (nodeName === 'A' && (isModifiedEvent(e) || !isLocalURL(href))) {
+  // anchors inside an svg have a lowercase nodeName
+  const isAnchorNodeName = nodeName.toUpperCase() === 'A'
+
+  if (isAnchorNodeName && (isModifiedEvent(e) || !isLocalURL(href))) {
     // ignore click for browser’s default behavior
     return
   }

test/integration/client-navigation/pages/nav/index.js

@@ -78,14 +78,33 @@ export default class extends Component {
         </Link>
         <Link href="/nav/on-click?count=1">
           <a id="on-click-link" style={linkStyle}>
-            A element with onClick
+            An element with onClick
           </a>
         </Link>
         <Link href="/nav/about">
           <a id="target-link" target="_blank">
-            A element with target
+            An element with target
           </a>
         </Link>
+
+        <svg
+          width={24}
+          height={24}
+          fill="none"
+          xmlns="http://www.w3.org/2000/svg"
+        >
+          <Link href="/nav/about">
+            <a id="in-svg-link" style={{ display: 'block' }}>
+              <path
+                fillRule="evenodd"
+                clipRule="evenodd"
+                d="M12 0C5.373 0 0 5.373 0 12s5.373 12 12 12 12-5.373 12-12S18.627 0 12 0Zm4.5 18a4 4 0 1 0 0-8 4 4 0 0 0 0 8Z"
+                fill="#335BF1"
+              />
+            </a>
+          </Link>
+        </svg>
+
         <button
           onClick={() => this.visitQueryStringPage()}
           style={linkStyle}

test/integration/client-navigation/test/index.test.js

@@ -180,13 +180,35 @@ describe('Client Navigation', () => {
     it('should not navigate if the <a/> tag has a target', async () => {
       const browser = await webdriver(context.appPort, '/nav')
 
-      const counterText = await browser
+      await browser
         .elementByCss('#increase')
         .click()
         .elementByCss('#target-link')
         .click()
-        .elementByCss('#counter')
-        .text()
+
+      await waitFor(1000)
+
+      const counterText = await browser.elementByCss('#counter').text()
+
+      expect(counterText).toBe('Counter: 1')
+      await browser.close()
+    })
+
+    it('should not navigate if the click-event is modified', async () => {
+      const browser = await webdriver(context.appPort, '/nav')
+
+      await browser.elementByCss('#increase').click()
+
+      const key = process.platform === 'darwin' ? 'Meta' : 'Control'
+
+      await browser.keydown(key)
+
+      await browser.elementByCss('#in-svg-link').click()
+
+      await browser.keyup(key)
+      await waitFor(1000)
+
+      const counterText = await browser.elementByCss('#counter').text()
 
       expect(counterText).toBe('Counter: 1')
       await browser.close()
@@ -413,7 +435,6 @@ describe('Client Navigation', () => {
       }
     })
   })
-
   describe('resets scroll at the correct time', () => {
     it('should reset scroll before the new page runs its lifecycles (<Link />)', async () => {
       let browser

test/lib/browsers/base.ts

@@ -29,7 +29,16 @@ export class BrowserInterface {
   elementById(selector: string): BrowserInterface {
     return this
   }
-  click(): BrowserInterface {
+  click(opts?: { modifierKey?: boolean }): BrowserInterface {
+    return this
+  }
+  keydown(key: string): BrowserInterface {
+    return this
+  }
+  keyup(key: string): BrowserInterface {
+    return this
+  }
+  focusPage(): BrowserInterface {
     return this
   }
   type(text: string): BrowserInterface {

test/lib/browsers/playwright.ts

@@ -165,6 +165,10 @@ class Playwright extends BrowserInterface {
     return this.chain(async () => context.clearCookies())
   }
 
+  focusPage() {
+    return this.chain(() => page.bringToFront())
+  }
+
   private wrapElement(el: ElementHandle, selector: string) {
     ;(el as any).selector = selector
     ;(el as any).text = () => el.innerText()
@@ -237,6 +241,18 @@ class Playwright extends BrowserInterface {
     return this.eval(`!!document.querySelector('${selector}')`) as any
   }
 
+  keydown(key: string): BrowserInterface {
+    return this.chain((el) => {
+      return page.keyboard.down(key).then(() => el)
+    })
+  }
+
+  keyup(key: string): BrowserInterface {
+    return this.chain((el) => {
+      return page.keyboard.up(key).then(() => el)
+    })
+  }
+
   click() {
     return this.chain((el) => {
       return el.click().then(() => el)