feat(go): add platform principles and health probes

go/vehicle-gateway/internal/health/health_test.go

@@ -0,0 +1,98 @@
+package health
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestHandlerReturnsHealthyWhenAllChecksPass(t *testing.T) {
+	handler := NewHandler("vehicle-realtime-api", []Check{
+		{Name: "redis", Check: func(context.Context) error { return nil }},
+		{Name: "mysql", Check: func(context.Context) error { return nil }},
+	})
+	request := httptest.NewRequest(http.MethodGet, "/readyz", nil)
+	response := httptest.NewRecorder()
+
+	handler.ServeHTTP(response, request)
+
+	if response.Code != http.StatusOK {
+		t.Fatalf("status = %d body=%s", response.Code, response.Body.String())
+	}
+	body := response.Body.String()
+	for _, want := range []string{`"service":"vehicle-realtime-api"`, `"status":"ok"`, `"redis":{"status":"ok"`, `"mysql":{"status":"ok"`} {
+		if !strings.Contains(body, want) {
+			t.Fatalf("response missing %s: %s", want, body)
+		}
+	}
+}
+
+func TestHandlerReturnsServiceUnavailableWhenCheckFails(t *testing.T) {
+	handler := NewHandler("vehicle-history-writer", []Check{
+		{Name: "tdengine", Check: func(context.Context) error { return errors.New("ping failed") }},
+	})
+	request := httptest.NewRequest(http.MethodGet, "/readyz", nil)
+	response := httptest.NewRecorder()
+
+	handler.ServeHTTP(response, request)
+
+	if response.Code != http.StatusServiceUnavailable {
+		t.Fatalf("status = %d body=%s", response.Code, response.Body.String())
+	}
+	body := response.Body.String()
+	for _, want := range []string{`"service":"vehicle-history-writer"`, `"status":"degraded"`, `"tdengine":`, `"status":"error"`, `"error":"ping failed"`} {
+		if !strings.Contains(body, want) {
+			t.Fatalf("response missing %s: %s", want, body)
+		}
+	}
+}
+
+func TestHandlerRejectsUnknownPath(t *testing.T) {
+	handler := NewHandler("vehicle-gateway", nil)
+	request := httptest.NewRequest(http.MethodGet, "/metrics", nil)
+	response := httptest.NewRecorder()
+
+	handler.ServeHTTP(response, request)
+
+	if response.Code != http.StatusNotFound {
+		t.Fatalf("status = %d body=%s", response.Code, response.Body.String())
+	}
+}
+
+func TestNewMuxRegistersHealthAndReadinessRoutes(t *testing.T) {
+	mux := NewMux("vehicle-stat-writer", []Check{
+		{Name: "mysql", Check: func(context.Context) error { return nil }},
+	})
+	for _, path := range []string{"/healthz", "/readyz"} {
+		request := httptest.NewRequest(http.MethodGet, path, nil)
+		response := httptest.NewRecorder()
+
+		mux.ServeHTTP(response, request)
+
+		if response.Code != http.StatusOK {
+			t.Fatalf("%s status = %d body=%s", path, response.Code, response.Body.String())
+		}
+	}
+}
+
+func TestNewServerReturnsNilWhenAddressIsEmpty(t *testing.T) {
+	if server := NewServer("", "vehicle-gateway", nil); server != nil {
+		t.Fatalf("server = %#v, want nil", server)
+	}
+}
+
+func TestNewServerBuildsConfiguredHTTPServer(t *testing.T) {
+	server := NewServer(":20290", "vehicle-gateway", nil)
+	if server == nil {
+		t.Fatal("server is nil")
+	}
+	if server.Addr != ":20290" {
+		t.Fatalf("addr = %q", server.Addr)
+	}
+	if server.ReadHeaderTimeout == 0 {
+		t.Fatal("ReadHeaderTimeout should be configured")
+	}
+}