@uppy/xhr-upload: bring back getResponseData

[Murderlon]

Closes #5349

getResponseData was deleted for 4.0 as I thought onAfterResponse covers the use case as well but you can't modify the response from inside it. I tried altering onAfterResponse to allow you to return a body and deprecate the void signature with backwards compatibility, but it didn't feel right and onAfterResponse is also called after every request, even it it fails. getResponseData is only called once after success(full retries).

[github-actions]

Diff output files

diff --git a/packages/@uppy/xhr-upload/lib/index.js b/packages/@uppy/xhr-upload/lib/index.js
index c731d7e..e429261 100644
--- a/packages/@uppy/xhr-upload/lib/index.js
+++ b/packages/@uppy/xhr-upload/lib/index.js
@@ -133,6 +133,7 @@ export default class XHRUpload extends BasePlugin {
     _classPrivateFieldLooseBase(this, _getFetcher)[_getFetcher] = files => {
       return async (url, options) => {
         try {
+          var _this$opts$getRespons, _this$opts, _body2;
           const res = await fetcher(url, {
             ...options,
             onBeforeRequest: this.opts.onBeforeRequest,
@@ -160,8 +161,21 @@ export default class XHRUpload extends BasePlugin {
               }
             },
           });
-          const body = JSON.parse(res.responseText);
-          const uploadURL = typeof (body == null ? void 0 : body.url) === "string" ? body.url : undefined;
+          let body = await ((_this$opts$getRespons = (_this$opts = this.opts).getResponseData) == null
+            ? void 0
+            : _this$opts$getRespons.call(_this$opts, res));
+          try {
+            var _body;
+            (_body = body) != null ? _body : body = JSON.parse(res.responseText);
+          } catch (cause) {
+            throw new Error(
+              "@uppy/xhr-upload expects a JSON response (with a `url` property). To parse non-JSON responses, use `getResponseData` to turn your response into JSON.",
+              {
+                cause,
+              },
+            );
+          }
+          const uploadURL = typeof ((_body2 = body) == null ? void 0 : _body2.url) === "string" ? body.url : undefined;
           for (const file of files) {
             this.uppy.emit("upload-success", file, {
               status: res.status,

[aonnikov]

Sorry for interfering.

This code overrides the value returned by getResponseData. For me, as a user, this behavior would be unexpected. The responseText might be a proper JSON document but with wrong field names that I would like to modify in getResponseData. I propose to check whether getResponseData is provided before parsing the response.

[Murderlon]

That's not what happens here. Through optional chaining, getResponseData is only called if it exists, otherwise body is undefined. JSON.parse is only called if body is undefined (??=).

[aonnikov]

ah, overlooked this 😄 well done!