Add page path to repeated slashes in href error (#46557)

Currently if you find this error in your logs it's difficult to know
where it occurred. This adds the page pathname to the error message.

Before

![image](https://user-images.githubusercontent.com/25056922/221892504-383c0d31-5cc4-4e32-b317-9ebc42696151.png)

After

![image](https://user-images.githubusercontent.com/25056922/221892431-1dd2c3e5-b6aa-46a2-8ca9-3be266fee76f.png)

Ref:
[slack](https://vercel.slack.com/archives/C03KAR5DCKC/p1677527238287849?thread_ts=1677521794.667229&cid=C03KAR5DCKC)


## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see
[`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## 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`
- [ ]
[e2e](https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs)
tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have a helpful link attached, see
[`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm build && pnpm lint`
- [ ] The "examples guidelines" are followed from [our contributing
doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)

packages/next/src/shared/lib/router/utils/resolve-href.ts

@@ -43,7 +43,7 @@ export function resolveHref(
 
   if ((urlParts[0] || '').match(/(\/\/|\\)/)) {
     console.error(
-      `Invalid href passed to next/router: ${urlAsString}, repeated forward-slashes (//) or backslashes \\ are not valid in the href`
+      `Invalid href '${urlAsString}' passed to next/router in page: '${router.pathname}'. Repeated forward-slashes (//) or backslashes \\ are not valid in the href.`
     )
     const normalizedUrl = normalizeRepeatedSlashes(urlAsStringNoProto)
     urlAsString = (urlProtoMatch ? urlProtoMatch[0] : '') + normalizedUrl

test/e2e/repeated-forward-slashes-error/pages/my/path/[name].js

@@ -0,0 +1,5 @@
+import Link from 'next/link'
+
+export default function Page() {
+  return <Link href="/hello//world">Hello</Link>
+}

test/e2e/repeated-forward-slashes-error/repeated-forward-slashes-error.test.ts

@@ -0,0 +1,18 @@
+import { createNextDescribe } from 'e2e-utils'
+import { check } from 'next-test-utils'
+
+createNextDescribe(
+  'repeated-forward-slashes-error',
+  {
+    files: __dirname,
+  },
+  ({ next }) => {
+    it('should log error when href has repeated forward-slashes', async () => {
+      await next.render$('/my/path/name')
+      await check(() => next.cliOutput, /Invalid href/)
+      expect(next.cliOutput).toContain(
+        "Invalid href '/hello//world' passed to next/router in page: '/my/path/[name]'. Repeated forward-slashes (//) or backslashes \\ are not valid in the href."
+      )
+    })
+  }
+)

test/integration/repeated-slashes/test/index.test.js

@@ -303,7 +303,7 @@ function runTests({ isDev = false, isExport = false, isPages404 = false }) {
           browser.eval(
             'window.caughtErrors.map(err => typeof err !== "string" ? err.message : err).join(", ")'
           ),
-        new RegExp(escapeRegex(`Invalid href passed to next/router: ${href}`))
+        new RegExp(escapeRegex(`Invalid href '${href}'`))
       )
     }
   })