Add projects

backend/internal/logging/cpa_trace_test.go

@@ -0,0 +1,115 @@
+package logging
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+func TestFormatCPATraceID(t *testing.T) {
+	selectedAt := time.Date(2026, time.July, 17, 21, 58, 49, 0, time.UTC)
+	got := FormatCPATraceID(selectedAt, "auth-index", "request1")
+	if want := "20260717215849-auth-index-request1"; got != want {
+		t.Fatalf("FormatCPATraceID() = %q, want %q", got, want)
+	}
+
+	for _, test := range []struct {
+		name       string
+		selectedAt time.Time
+		authIndex  string
+		requestID  string
+	}{
+		{name: "zero time", authIndex: "auth-index", requestID: "request1"},
+		{name: "empty auth index", selectedAt: selectedAt, requestID: "request1"},
+		{name: "empty request ID", selectedAt: selectedAt, authIndex: "auth-index"},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			if gotEmpty := FormatCPATraceID(test.selectedAt, test.authIndex, test.requestID); gotEmpty != "" {
+				t.Fatalf("FormatCPATraceID() = %q, want empty", gotEmpty)
+			}
+		})
+	}
+}
+
+func TestCPATraceIDMiddlewareRequiresAuthIndexBeforeResponseCommit(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	engine := gin.New()
+	engine.Use(CPATraceIDMiddleware())
+	engine.GET("/selected", func(c *gin.Context) {
+		SetGinRequestID(c, "1234abcd")
+		SetGinCPATraceID(c, "auth-index")
+		c.Status(http.StatusOK)
+	})
+	engine.GET("/unselected", func(c *gin.Context) {
+		SetGinRequestID(c, "1234abcd")
+		SetGinCPATraceID(c, "")
+		c.Status(http.StatusOK)
+	})
+	engine.GET("/committed", func(c *gin.Context) {
+		SetGinRequestID(c, "1234abcd")
+		c.Writer.WriteHeaderNow()
+		SetGinCPATraceID(c, "auth-index")
+	})
+
+	t.Run("writes selected auth trace", func(t *testing.T) {
+		recorder := httptest.NewRecorder()
+		engine.ServeHTTP(recorder, httptest.NewRequest(http.MethodGet, "/selected", nil))
+
+		traceID := recorder.Header().Get(CPATraceIDHeader)
+		if len(traceID) != len("20060102150405-auth-index-1234abcd") {
+			t.Fatalf("trace ID = %q, unexpected length", traceID)
+		}
+		if got := traceID[15:]; got != "auth-index-1234abcd" {
+			t.Fatalf("trace suffix = %q, want %q", got, "auth-index-1234abcd")
+		}
+	})
+
+	t.Run("skips empty auth index", func(t *testing.T) {
+		recorder := httptest.NewRecorder()
+		engine.ServeHTTP(recorder, httptest.NewRequest(http.MethodGet, "/unselected", nil))
+
+		if got := recorder.Header().Get(CPATraceIDHeader); got != "" {
+			t.Fatalf("trace ID = %q, want empty", got)
+		}
+	})
+
+	t.Run("skips committed response", func(t *testing.T) {
+		recorder := httptest.NewRecorder()
+		engine.ServeHTTP(recorder, httptest.NewRequest(http.MethodGet, "/committed", nil))
+
+		if got := recorder.Header().Get(CPATraceIDHeader); got != "" {
+			t.Fatalf("trace ID = %q, want empty", got)
+		}
+	})
+}
+
+func TestCPATraceIDConcurrentSelectionAndResponseCommit(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	engine := gin.New()
+	engine.Use(CPATraceIDMiddleware())
+	engine.GET("/race", func(c *gin.Context) {
+		SetGinRequestID(c, "1234abcd")
+		traceCallback := GinCPATraceIDCallback(c)
+		start := make(chan struct{})
+		done := make(chan struct{})
+		go func() {
+			defer close(done)
+			<-start
+			traceCallback("auth-index")
+		}()
+		close(start)
+		_, _ = c.Writer.Write([]byte("\n"))
+		<-done
+	})
+
+	for range 100 {
+		recorder := httptest.NewRecorder()
+		engine.ServeHTTP(recorder, httptest.NewRequest(http.MethodGet, "/race", nil))
+		if recorder.Code != http.StatusOK {
+			t.Fatalf("status = %d, want %d", recorder.Code, http.StatusOK)
+		}
+	}
+}