veza/veza-backend-api/internal/services/circuit_breaker_test.go

package services

import (
	"context"
	"fmt"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/sony/gobreaker"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap/zaptest"
)

func TestNewCircuitBreakerHTTPClient(t *testing.T) {
	logger := zaptest.NewLogger(t)
	client := &http.Client{Timeout: 5 * time.Second}

	cbClient := NewCircuitBreakerHTTPClient(client, "test-circuit", logger)

	assert.NotNil(t, cbClient)
	assert.NotNil(t, cbClient.client)
	assert.NotNil(t, cbClient.circuitBreaker)
	assert.Equal(t, "test-circuit", cbClient.circuitBreaker.Name())
	assert.Equal(t, gobreaker.StateClosed, cbClient.circuitBreaker.State())
}

func TestCircuitBreakerHTTPClient_Do_Success(t *testing.T) {
	logger := zaptest.NewLogger(t)

	// Mock server qui retourne 200 OK
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("OK"))
	}))
	defer server.Close()

	client := &http.Client{Timeout: 5 * time.Second}
	cbClient := NewCircuitBreakerHTTPClient(client, "test-success", logger)

	req, err := http.NewRequest("GET", server.URL, nil)
	require.NoError(t, err)

	resp, err := cbClient.Do(req)
	require.NoError(t, err)
	assert.NotNil(t, resp)
	assert.Equal(t, http.StatusOK, resp.StatusCode)
	resp.Body.Close()

	// Vérifier que le circuit breaker est toujours fermé
	assert.Equal(t, gobreaker.StateClosed, cbClient.circuitBreaker.State())
}

func TestCircuitBreakerHTTPClient_Do_ServerError(t *testing.T) {
	logger := zaptest.NewLogger(t)

	// Mock server qui retourne 500
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer server.Close()

	client := &http.Client{Timeout: 5 * time.Second}
	// Créer un circuit breaker avec seuil bas pour tester rapidement
	cb := gobreaker.NewCircuitBreaker(gobreaker.Settings{
		Name:        "test-5xx",
		MaxRequests: 3,
		Interval:    1 * time.Second,
		Timeout:     1 * time.Second,
		ReadyToTrip: func(counts gobreaker.Counts) bool {
			return counts.ConsecutiveFailures >= 3 // S'ouvre après 3 échecs
		},
	})

	cbClient := &CircuitBreakerHTTPClient{
		client:         client,
		circuitBreaker: cb,
		logger:         logger,
	}

	// Faire 3 requêtes qui échouent (500)
	for i := 0; i < 3; i++ {
		req, err := http.NewRequest("GET", server.URL, nil)
		require.NoError(t, err)

		resp, err := cbClient.Do(req)
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "server error: 500")
		if resp != nil {
			resp.Body.Close()
		}
	}

	// Vérifier que le circuit breaker est maintenant ouvert
	// Note: Il peut y avoir un délai, donc on vérifie après un court instant
	time.Sleep(100 * time.Millisecond)
	state := cbClient.circuitBreaker.State()
	assert.True(t, state == gobreaker.StateOpen || state == gobreaker.StateHalfOpen,
		fmt.Sprintf("Expected Open or HalfOpen, got %v", state))
}

func TestCircuitBreakerHTTPClient_Do_OpenState(t *testing.T) {
	logger := zaptest.NewLogger(t)

	client := &http.Client{Timeout: 5 * time.Second}
	// Créer un circuit breaker déjà ouvert
	cb := gobreaker.NewCircuitBreaker(gobreaker.Settings{
		Name:        "test-open",
		MaxRequests: 1,
		Interval:    1 * time.Second,
		Timeout:     1 * time.Second,
		ReadyToTrip: func(counts gobreaker.Counts) bool {
			return counts.ConsecutiveFailures >= 1
		},
	})

	// Forcer l'ouverture en faisant échouer une requête
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer server.Close()

	req, _ := http.NewRequest("GET", server.URL, nil)
	cb.Execute(func() (interface{}, error) {
		return nil, fmt.Errorf("test error")
	})

	cbClient := &CircuitBreakerHTTPClient{
		client:         client,
		circuitBreaker: cb,
		logger:         logger,
	}

	// Attendre que le circuit breaker s'ouvre
	time.Sleep(100 * time.Millisecond)

	// Tenter une nouvelle requête - devrait être rejetée
	req, err := http.NewRequest("GET", server.URL, nil)
	require.NoError(t, err)

	resp, err := cbClient.Do(req)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "circuit breaker is open")
	assert.Nil(t, resp)
}

func TestCircuitBreakerHTTPClient_DoWithContext(t *testing.T) {
	logger := zaptest.NewLogger(t)

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	client := &http.Client{Timeout: 5 * time.Second}
	cbClient := NewCircuitBreakerHTTPClient(client, "test-context", logger)

	ctx := context.Background()
	req, err := http.NewRequest("GET", server.URL, nil)
	require.NoError(t, err)

	resp, err := cbClient.DoWithContext(ctx, req)
	require.NoError(t, err)
	assert.NotNil(t, resp)
	assert.Equal(t, http.StatusOK, resp.StatusCode)
	resp.Body.Close()
}

func TestCircuitBreakerHTTPClient_DoWithContext_Cancelled(t *testing.T) {
	logger := zaptest.NewLogger(t)

	// Mock server qui prend du temps
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		time.Sleep(2 * time.Second)
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	client := &http.Client{Timeout: 5 * time.Second}
	cbClient := NewCircuitBreakerHTTPClient(client, "test-cancelled", logger)

	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()

	req, err := http.NewRequest("GET", server.URL, nil)
	require.NoError(t, err)

	resp, err := cbClient.DoWithContext(ctx, req)
	assert.Error(t, err)
	assert.Nil(t, resp)
	assert.Contains(t, err.Error(), "context deadline exceeded")
}