feat(ux): enhance media-type switching experience in RequestBodyEditor (#6837)

* feat(ux): enhance media-type switching experience in RequestBodyEditor

1. When canceling the try-out mode the request body will be reset to its initial state.
2. When the user switches the media-type in the try-out mode, the experience is as follows:
   - If the user did edit the request body the body wont be touched and only media type is updated. This is to ensure that user content is NEVER accidentally overwritten with a default value.
   - If the user did not edit the request body it is safe to be replaced by the default value of the target media-type.

Multiple example needed some care in order to allow the retain example value to function properly

* fix(test): workaround cypress issue that can't be reproduced manually

* test: added new feature to ensure enhanced user editing flow

Signed-off-by: mathis-m <mathis.michel@outlook.de>

src/core/plugins/oas3/selectors.js

@@ -1,5 +1,7 @@
-import { OrderedMap, Map } from "immutable"
+import { OrderedMap, Map, List } from "immutable"
 import { isOAS3 as isOAS3Helper } from "./helpers"
+import { getDefaultRequestBodyValue } from "./components/request-body"
+import { stringify } from "../../utils"
 
 // Helpers
 
@@ -54,6 +56,43 @@ export const requestBodyValue = onlyOAS3((state, path, method) => {
   }
 )
 
+export const shouldRetainRequestBodyValue = onlyOAS3((state, path, method) => {
+    return state.getIn(["requestData", path, method, "retainBodyValue"]) || false
+  }
+)
+
+export const hasUserEditedBody = (state, path, method) => (system) => {
+  const {oas3Selectors, specSelectors} = system.getSystem()
+  const spec = specSelectors.specJson()
+  if(isOAS3Helper(spec)) {
+    let userHasEditedBody = false
+    const currentMediaType = oas3Selectors.requestContentType(path, method)
+    let userEditedRequestBody = oas3Selectors.requestBodyValue(path, method)
+    if (Map.isMap(userEditedRequestBody)) {
+      // context is not application/json media-type
+      userEditedRequestBody = stringify(userEditedRequestBody.mapEntries((kv) => Map.isMap(kv[1]) ? [kv[0], kv[1].get("value")] : kv).toJS())
+    }
+    if(List.isList(userEditedRequestBody)) {
+      userEditedRequestBody = stringify(userEditedRequestBody)
+    }
+    if (currentMediaType) {
+      const currentMediaTypeDefaultBodyValue = getDefaultRequestBodyValue(
+        specSelectors.specResolvedSubtree(["paths", path, method, "requestBody"]),
+        currentMediaType,
+        oas3Selectors.activeExamplesMember(
+          path, method,
+          "requestBody",
+          "requestBody",
+        )
+      )
+      userHasEditedBody = !!userEditedRequestBody && userEditedRequestBody !== currentMediaTypeDefaultBodyValue
+    }
+    return userHasEditedBody
+  } else {
+    return null
+  }
+}
+
 export const requestBodyInclusionSetting = onlyOAS3((state, path, method) => {
     return state.getIn(["requestData", path, method, "bodyInclusion"]) || Map()
   }