Remove superfluous checks

src/engine/Server.cpp

@@ -747,15 +747,8 @@ MediaType Server::determineMediaType(
   if (!mediaType.has_value()) {
     mediaType = ad_utility::getMediaTypeFromAcceptHeader(acceptHeader);
   }
+  AD_CORRECTNESS_CHECK(mediaType.has_value());
 
-  if (!mediaType.has_value()) {
-    throw NoSupportedMediatypeError(
-        absl::StrCat("Did not find any supported media type "
-                     "in this \'Accept:\' header field: \"",
-                     acceptHeader, "\". ",
-                     ad_utility::getErrorMessageForSupportedMediaTypes()));
-  }
-  AD_CONTRACT_CHECK(mediaType.has_value());
   return mediaType.value();
 }
 

src/util/http/MediaTypes.h

@@ -112,6 +112,8 @@ std::vector<MediaTypeWithQuality> parseAcceptHeader(
 /// media types that appear earlier in the `SUPPORTED_MEDIA_TYPES`. If none of
 /// the `SUPPORTED_MEDIA_TYPES` is accepted by `acceptHeader`, then
 /// `std::nullopt` is returned.
+// TODO: An exception is thrown if no supported media type is found. Update the
+// docstring and signature to reflect this.
 std::optional<MediaType> getMediaTypeFromAcceptHeader(
     std::string_view acceptHeader);
 

test/ServerTest.cpp

@@ -208,7 +208,9 @@ TEST(ServerTest, determineMediaType) {
   EXPECT_THAT(Server::determineMediaType(
                   {}, MakeRequest("application/sparql-results+json")),
               testing::Eq(ad_utility::MediaType::sparqlJson));
-  // No supported media type.
+  // No supported media type in the `Accept` header. (Contrary to it's docstring
+  // and interface) `ad_utility::getMediaTypeFromAcceptHeader` throws an
+  // exception if no supported media type is found.
   EXPECT_THROW(Server::determineMediaType({}, MakeRequest("text/css")),
                std::runtime_error);
   // No `Accept` header means that any content type is allowed.