Auto merge of #14868 - bd339:iss14068, r=jdm

Fix loss of response type information in Fetch API

<!-- Please describe your changes on the following line: -->
Avoids mapping response types that are distinct according to [the spec](https://fetch.spec.whatwg.org/#concept-response-type) to fewer response types. Also updates test expectations to match that we now pass tests that check the response type.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #14068

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- [X] There are tests for these changes

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components/net_traits/lib.rs

@@ -172,8 +172,10 @@ pub trait FetchTaskTarget {
 
 #[derive(Serialize, Deserialize)]
 pub enum FilteredMetadata {
+    Basic(Metadata),
+    Cors(Metadata),
     Opaque,
-    Transparent(Metadata),
+    OpaqueRedirect
 }
 
 #[derive(Serialize, Deserialize)]

components/net_traits/response.rs

@@ -270,17 +270,32 @@ impl Response {
                 Some(ref url) => {
                     let unsafe_metadata = init_metadata(response, url);
 
-                    Ok(FetchMetadata::Filtered {
-                        filtered: match metadata {
-                            Some(m) => FilteredMetadata::Transparent(m),
-                            None => FilteredMetadata::Opaque,
-                        },
-                        unsafe_: unsafe_metadata,
-                    })
+                    match self.response_type {
+                        ResponseType::Basic => Ok(FetchMetadata::Filtered {
+                            filtered: FilteredMetadata::Basic(metadata.unwrap()),
+                            unsafe_: unsafe_metadata
+                        }),
+                        ResponseType::Cors => Ok(FetchMetadata::Filtered {
+                            filtered: FilteredMetadata::Cors(metadata.unwrap()),
+                            unsafe_: unsafe_metadata
+                        }),
+                        ResponseType::Default => unreachable!(),
+                        ResponseType::Error(ref network_err) =>
+                            Err(network_err.clone()),
+                        ResponseType::Opaque => Ok(FetchMetadata::Filtered {
+                            filtered: FilteredMetadata::Opaque,
+                            unsafe_: unsafe_metadata
+                        }),
+                        ResponseType::OpaqueRedirect => Ok(FetchMetadata::Filtered {
+                            filtered: FilteredMetadata::OpaqueRedirect,
+                            unsafe_: unsafe_metadata
+                        })
+                    }
                 },
-                None => Err(NetworkError::Internal("No url found in unsafe response".to_owned())),
+                None => Err(NetworkError::Internal("No url found in unsafe response".to_owned()))
             }
         } else {
+            assert_eq!(self.response_type, ResponseType::Default);
             Ok(FetchMetadata::Unfiltered(metadata.unwrap()))
         }
     }

components/script/dom/xmlhttprequest.rs

@@ -854,8 +854,10 @@ impl XMLHttpRequest {
             Ok(meta) => match meta {
                 FetchMetadata::Unfiltered(m) => m,
                 FetchMetadata::Filtered { filtered, .. } => match filtered {
+                    FilteredMetadata::Basic(m) => m,
+                    FilteredMetadata::Cors(m) => m,
                     FilteredMetadata::Opaque => return Err(Error::Network),
-                    FilteredMetadata::Transparent(m) => m
+                    FilteredMetadata::OpaqueRedirect => return Err(Error::Network)
                 }
             },
             Err(_) => {

components/script/fetch.rs

@@ -135,18 +135,29 @@ impl FetchResponseListener for FetchContext {
                     promise.global().get_cx(),
                     Error::Type("Network error occurred".to_string()));
                 self.fetch_promise = Some(TrustedPromise::new(promise));
+                self.response_object.root().set_type(DOMResponseType::Error);
                 return;
             },
             // Step 4.2
             Ok(metadata) => {
                 match metadata {
-                    FetchMetadata::Unfiltered(m) =>
-                        fill_headers_with_metadata(self.response_object.root(), m),
+                    FetchMetadata::Unfiltered(m) => {
+                        fill_headers_with_metadata(self.response_object.root(), m);
+                        self.response_object.root().set_type(DOMResponseType::Default);
+                    },
                     FetchMetadata::Filtered { filtered, .. } => match filtered {
-                        FilteredMetadata::Transparent(m) =>
-                            fill_headers_with_metadata(self.response_object.root(), m),
+                        FilteredMetadata::Basic(m) => {
+                            fill_headers_with_metadata(self.response_object.root(), m);
+                            self.response_object.root().set_type(DOMResponseType::Basic);
+                        },
+                        FilteredMetadata::Cors(m) => {
+                            fill_headers_with_metadata(self.response_object.root(), m);
+                            self.response_object.root().set_type(DOMResponseType::Cors);
+                        },
                         FilteredMetadata::Opaque =>
                             self.response_object.root().set_type(DOMResponseType::Opaque),
+                        FilteredMetadata::OpaqueRedirect =>
+                            self.response_object.root().set_type(DOMResponseType::Opaqueredirect)
                     }
                 }
             }