From ff9be3a43a0f3ba43b94a4080b9e0cd8ed4cb7d0 Mon Sep 17 00:00:00 2001
From: Julian Mundhahs <julian.mundhahs@gmail.com>
Date: Sun, 27 Oct 2024 16:53:34 +0100
Subject: [PATCH] Remove superfluous checks

---
 src/engine/Server.cpp      | 9 +--------
 src/util/http/MediaTypes.h | 2 ++
 test/ServerTest.cpp        | 4 +++-
 3 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/src/engine/Server.cpp b/src/engine/Server.cpp
index e3511d46ee..8d1afd099e 100644
--- a/src/engine/Server.cpp
+++ b/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();
 }
 
diff --git a/src/util/http/MediaTypes.h b/src/util/http/MediaTypes.h
index 43a809e33b..407473bd21 100644
--- a/src/util/http/MediaTypes.h
+++ b/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);
 
diff --git a/test/ServerTest.cpp b/test/ServerTest.cpp
index 23c64f1882..3f32356935 100644
--- a/test/ServerTest.cpp
+++ b/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.