✨ Add repository guidelines and enhance documentation for project structure, build commands, coding standards, and testing practices. Introduce AGENTS.md for contributor guidance, update README.md to reference new guidelines, and improve configuration documentation for NATS modes. Update Makefile and Taskfile with clearer run commands and requirements for development and production modes. Add production deployment guide and improve logging configuration for better observability.

internal/infra/metrics/metrics_test.go

@@ -0,0 +1,53 @@
+package metrics
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestMetrics(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Metrics Suite")
+}
+
+var _ = Describe("Metrics", func() {
+	Describe("Handler", func() {
+		It("serves metrics with the correct content type", func() {
+			req := httptest.NewRequest(http.MethodGet, "/metrics", nil)
+			resp := httptest.NewRecorder()
+
+			Handler().ServeHTTP(resp, req)
+
+			Expect(resp.Code).To(Equal(http.StatusOK))
+			Expect(resp.Header().Get("Content-Type")).To(ContainSubstring("text/plain"))
+		})
+	})
+
+	Describe("labelValue helper", func() {
+		It("returns unknown for empty values and lowercases input", func() {
+			Expect(labelValue("   ")).To(Equal("unknown"))
+			Expect(labelValue("SOME_VALUE")).To(Equal("some_value"))
+		})
+	})
+
+	Describe("record helpers", func() {
+		It("can be invoked without panicking", func() {
+			Expect(func() {
+				RecordProcessed("parsed", "ARR", 150*time.Millisecond)
+				RecordFailure("parser")
+				RecordMessageHandled("TEST", "consumer", ResultOK, 205*time.Millisecond)
+				RecordRetry("TEST", "consumer", RetryReasonProcessorError)
+				RecordDLQMessage("TEST", "consumer")
+				RecordDLQPublishFailure("TEST", "consumer")
+				RecordDBQuery("insert", DBResultOK, 10*time.Millisecond)
+				RecordJSAPICall("publish")
+				RecordNATSConsumerPending("TEST", "consumer", 7)
+			}).NotTo(Panic())
+		})
+	})
+})