Check if server error already had its message updated (#46367)

I haven't been able to reproduce this consistently. But sometimes it
seems that the same error instance is thrown, causing the additional
error info to be appended multiple times. This adds a check to see if
the error message already has been updated, and ignores it if that's the
case.

Example

![image](https://user-images.githubusercontent.com/25056922/221200780-4b7f4047-4e43-4ae2-9b6e-456b650cd091.png)


## 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)

---------

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

packages/next/src/lib/format-server-error.test.ts

@@ -0,0 +1,30 @@
+import { formatServerError } from './format-server-error'
+
+describe('formatServerError', () => {
+  it('should not append message several times', () => {
+    const err = new Error(
+      'Class extends value undefined is not a constructor or null'
+    )
+
+    // Before
+    expect(err.message).toMatchInlineSnapshot(
+      `"Class extends value undefined is not a constructor or null"`
+    )
+
+    // After
+    formatServerError(err)
+    expect(err.message).toMatchInlineSnapshot(`
+      "Class extends value undefined is not a constructor or null
+
+      This might be caused by a React Class Component being rendered in a Server Component, React Class Components only works in Client Components. Read more: https://nextjs.org/docs/messages/class-component-in-server-component"
+    `)
+
+    // After second
+    formatServerError(err)
+    expect(err.message).toMatchInlineSnapshot(`
+      "Class extends value undefined is not a constructor or null
+
+      This might be caused by a React Class Component being rendered in a Server Component, React Class Components only works in Client Components. Read more: https://nextjs.org/docs/messages/class-component-in-server-component"
+    `)
+  })
+})

packages/next/src/lib/format-server-error.ts

@@ -28,11 +28,17 @@ export function formatServerError(error: Error): void {
       'Class extends value undefined is not a constructor or null'
     )
   ) {
+    const addedMessage =
+      'This might be caused by a React Class Component being rendered in a Server Component, React Class Components only works in Client Components. Read more: https://nextjs.org/docs/messages/class-component-in-server-component'
+
+    // If this error instance already has the message, don't add it again
+    if (error.message.includes(addedMessage)) return
+
     setMessage(
       error,
       `${error.message}
 
-This might be caused by a React Class Component being rendered in a Server Component, React Class Components only works in Client Components. Read more: https://nextjs.org/docs/messages/class-component-in-server-component`
+${addedMessage}`
     )
     return
   }