Force encode request body if it's a string

CHANGELOG.md

@@ -6,6 +6,11 @@
 - Add tracing support to `sentry-resque` [#1480](https://github.com/getsentry/sentry-ruby/pull/1480)
 - Set user to the current scope via sidekiq middleware [#1469](https://github.com/getsentry/sentry-ruby/pull/1469)
 
+### Bug Fixes
+
+- Force encode request body if it's a string [#1484](https://github.com/getsentry/sentry-ruby/pull/1484)
+  - Fixes [#1475](https://github.com/getsentry/sentry-ruby/issues/1475) and [#1303](https://github.com/getsentry/sentry-ruby/issues/1303)
+
 ## 4.5.2
 
 ### Refactoring

sentry-ruby/lib/sentry/interfaces/request.rb

@@ -57,6 +57,7 @@ def read_data_from(request)
         request.POST
       elsif request.body # JSON requests, etc
         data = request.body.read(MAX_BODY_LIMIT)
+        data = data.force_encoding(Encoding::UTF_8) if data.respond_to?(:force_encoding)
         request.body.rewind
         data
       end

sentry-ruby/spec/sentry/interfaces/request_interface_spec.rb

@@ -210,6 +210,16 @@ def to_s
       expect(interface.data).to eq("catch me")
     end
 
+    it "force encodes request body to avoid encoding issue" do
+      new_env = env.merge(::Rack::RACK_INPUT => StringIO.new("あ"))
+
+      interface = described_class.build(env: new_env)
+
+      expect do
+        JSON.generate(interface.to_hash)
+      end.not_to raise_error
+    end
+
     it "doesn't remove ip address headers" do
       ip = "1.1.1.1"