Refactor error handling for API endpoints

src/invidious/helpers/handlers.cr

@@ -33,8 +33,7 @@ class Kemal::RouteHandler
       raise Kemal::Exceptions::CustomException.new(context)
     end
 
-    if context.request.method == "HEAD" &&
+    if context.request.method == "HEAD" && context.request.path.ends_with? ".jpg"
-       context.request.path.ends_with? ".jpg"
       context.response.headers["Content-Type"] = "image/jpeg"
     end
 
@@ -172,7 +171,7 @@ class APIHandler < Kemal::Handler
           end
         end
 
-        if env.params.query["pretty"]? && env.params.query["pretty"] == "1"
+        if env.params.query["pretty"]?.try &.== "1"
           response = response.to_pretty_json
         else
           response = response.to_json
@@ -181,6 +180,18 @@ class APIHandler < Kemal::Handler
         response = env.response.output.gets_to_end
       end
     rescue ex
+      env.response.content_type = "application/json" if env.response.headers.includes_word?("Content-Type", "text/html")
+      env.response.status_code = 500
+
+      if env.response.headers.includes_word?("Content-Type", "application/json")
+        response = {"error" => ex.message || "Unspecified error"}
+
+        if env.params.query["pretty"]?.try &.== "1"
+          response = response.to_pretty_json
+        else
+          response = response.to_json
+        end
+      end
     ensure
       env.response.output = output
       env.response.puts response