✨ Update agent guidelines and improve documentation structure. Refactor AGENTS.md to streamline commands and code style guidelines, enhancing clarity and usability. Update README.md with refined NATS consumer configuration details and observability metrics. Modify .gitignore to exclude dynamically generated Prometheus target files. Enhance configuration files for development and production environments, ensuring consistency and clarity in settings.

internal/infra/nats/message_fetcher_test.go

@@ -0,0 +1,89 @@
+package nats
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	configpkg "caatsm/internal/infra/config"
+
+	"github.com/nats-io/nats.go"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zaptest"
+)
+
+var _ = Describe("MessageFetcher", func() {
+	var (
+		fetcher *defaultMessageFetcher
+		logger  *zap.Logger
+	)
+
+	BeforeEach(func() {
+		logger = zaptest.NewLogger(GinkgoT())
+		fetcher = &defaultMessageFetcher{
+			logger: logger,
+			config: &consumerConfig{
+				streamName:   "TEST_STREAM",
+				consumerName: "test-consumer",
+			},
+			cfg: &configpkg.Config{
+				NATS: configpkg.NATSConfig{
+					ConsumerRules: configpkg.ConsumerRulesConfig{
+						Backoff: []time.Duration{5 * time.Second, 30 * time.Second},
+					},
+				},
+			},
+		}
+	})
+
+	Describe("HandleFetchError", func() {
+		var ctx context.Context
+
+		BeforeEach(func() {
+			ctx = context.Background()
+		})
+
+		It("returns true for timeout errors", func() {
+			var sub *nats.Subscription
+			fetchErrorStreak := 0
+			shouldContinue, err := fetcher.HandleFetchError(ctx, nats.ErrTimeout, &sub, &fetchErrorStreak)
+			Expect(shouldContinue).To(BeTrue())
+			Expect(err).NotTo(HaveOccurred())
+		})
+
+		It("handles ErrNoResponders with backoff", func() {
+			var sub *nats.Subscription
+			fetchErrorStreak := 0
+			shouldContinue, err := fetcher.HandleFetchError(ctx, nats.ErrNoResponders, &sub, &fetchErrorStreak)
+			Expect(shouldContinue).To(BeTrue())
+			Expect(err).NotTo(HaveOccurred())
+			Expect(fetchErrorStreak).To(Equal(1))
+		})
+
+		It("handles resource not found errors", func() {
+			var sub *nats.Subscription
+			fetchErrorStreak := 0
+			resourceErr := errors.New("stream not found")
+			shouldContinue, err := fetcher.HandleFetchError(ctx, resourceErr, &sub, &fetchErrorStreak)
+			// Simplified error handling just applies backoff and continues
+			Expect(err).NotTo(HaveOccurred())
+			Expect(shouldContinue).To(BeTrue())
+			Expect(fetchErrorStreak).To(Equal(1))
+		})
+
+		It("handles generic errors with backoff", func() {
+			// We need a non-nil subscription to avoid recovery attempt
+			dummySub := &nats.Subscription{}
+			sub := dummySub
+
+			fetchErrorStreak := 0
+			genericErr := errors.New("generic error")
+			shouldContinue, err := fetcher.HandleFetchError(ctx, genericErr, &sub, &fetchErrorStreak)
+			Expect(shouldContinue).To(BeTrue())
+			Expect(err).NotTo(HaveOccurred())
+			Expect(fetchErrorStreak).To(Equal(1))
+		})
+	})
+})