docs: mention issues with buffer encoding (#12141)

docs/api/puppeteer.httpresponse.buffer.md

@@ -17,3 +17,7 @@ class HTTPResponse {
 **Returns:**
 
 Promise<Buffer>
+
+## Remarks
+
+The buffer might be re-encoded by the browser based on HTTP-headers or other heuristics. If the browser failed to detect the correct encoding, the buffer might be encoded incorrectly. See https://github.com/puppeteer/puppeteer/issues/6478.

docs/api/puppeteer.httpresponse.md

@@ -171,7 +171,7 @@ The status text of the response (e.g. usually an "OK" for a success).
 
 </td><td>
 
-Promise which resolves to a text representation of response body.
+Promise which resolves to a text (utf8) representation of response body.
 
 </td></tr>
 <tr><td>

docs/api/puppeteer.httpresponse.text.md

@@ -4,7 +4,7 @@ sidebar_label: HTTPResponse.text
 
 # HTTPResponse.text() method
 
-Promise which resolves to a text representation of response body.
+Promise which resolves to a text (utf8) representation of response body.
 
 #### Signature:
 

packages/puppeteer-core/src/api/HTTPResponse.ts

@@ -81,11 +81,18 @@ export abstract class HTTPResponse {
 
   /**
    * Promise which resolves to a buffer with response body.
+   *
+   * @remarks
+   *
+   * The buffer might be re-encoded by the browser
+   * based on HTTP-headers or other heuristics. If the browser
+   * failed to detect the correct encoding, the buffer might
+   * be encoded incorrectly. See https://github.com/puppeteer/puppeteer/issues/6478.
    */
   abstract buffer(): Promise<Buffer>;
 
   /**
-   * Promise which resolves to a text representation of response body.
+   * Promise which resolves to a text (utf8) representation of response body.
    */
   async text(): Promise<string> {
     const content = await this.buffer();