wip - add a spec for failure message

sentry-ruby/spec/sentry/rspec/matchers_spec.rb

@@ -47,7 +47,7 @@
 
       Sentry.capture_exception(exception)
 
-      expect(sentry_events).not_to include_sentry_event(exception: RuntimeError, message: "Oops!")
+      expect(sentry_events).not_to include_sentry_event(exception: StandardError, message: "Gaah!")
     end
 
     it "matches events with context" do
@@ -106,5 +106,18 @@
         context: { "rails.error" => { some: "stuff" } }
       )
     end
+
+    it "produces a useful failure message" do
+      Sentry.capture_message("Actual message")
+
+      expect {
+        expect(sentry_events).to include_sentry_event("Expected message")
+      }.to raise_error(RSpec::Expectations::ExpectationNotMetError) do |error|
+        expect(error.message).to include("Failed to find event matching:")
+        expect(error.message).to include("message: \"Expected message\"")
+        expect(error.message).to include("Captured events:")
+        expect(error.message).to include("\"message\": \"Actual message\"")
+      end
+    end
   end
 end