feat(otelecho): add SpanNameFormatter config and tests

instrumentation/github.com/labstack/echo/otelecho/config.go

@@ -4,17 +4,27 @@
 package otelecho // import "go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho"
 
 import (
+	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
 
 	"go.opentelemetry.io/otel/propagation"
 	oteltrace "go.opentelemetry.io/otel/trace"
 )
 
+// defaultSpanNameFormatter is the default function used for formatting span names.
+var defaultSpanNameFormatter = func(c echo.Context) string {
+	return c.Path()
+}
+
+// SpanNameFormatter is a function that takes an echo.Context and returns a span name.
+type SpanNameFormatter func(c echo.Context) string
+
 // config is used to configure the mux middleware.
 type config struct {
-	TracerProvider oteltrace.TracerProvider
-	Propagators    propagation.TextMapPropagator
-	Skipper        middleware.Skipper
+	TracerProvider    oteltrace.TracerProvider
+	Propagators       propagation.TextMapPropagator
+	Skipper           middleware.Skipper
+	spanNameFormatter SpanNameFormatter
 }
 
 // Option specifies instrumentation configuration options.
@@ -55,3 +65,12 @@ func WithSkipper(skipper middleware.Skipper) Option {
 		cfg.Skipper = skipper
 	})
 }
+
+// WithSpanNameFormatter specifies a function to use for formatting span names.
+func WithSpanNameFormatter(formatter SpanNameFormatter) Option {
+	return optionFunc(func(cfg *config) {
+		if formatter != nil {
+			cfg.spanNameFormatter = formatter
+		}
+	})
+}

instrumentation/github.com/labstack/echo/otelecho/echo.go

@@ -11,11 +11,12 @@ import (
 
 	"go.opentelemetry.io/otel"
 
-	"go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho/internal/semconvutil"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/propagation"
 	semconv "go.opentelemetry.io/otel/semconv/v1.20.0"
 	oteltrace "go.opentelemetry.io/otel/trace"
+
+	"go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho/internal/semconvutil"
 )
 
 const (
@@ -45,6 +46,10 @@ func Middleware(service string, opts ...Option) echo.MiddlewareFunc {
 		cfg.Skipper = middleware.DefaultSkipper
 	}
 
+	if cfg.spanNameFormatter == nil {
+		cfg.spanNameFormatter = defaultSpanNameFormatter
+	}
+
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
 			if cfg.Skipper(c) {
@@ -67,7 +72,7 @@ func Middleware(service string, opts ...Option) echo.MiddlewareFunc {
 				rAttr := semconv.HTTPRoute(path)
 				opts = append(opts, oteltrace.WithAttributes(rAttr))
 			}
-			spanName := c.Path()
+			spanName := cfg.spanNameFormatter(c)
 			if spanName == "" {
 				spanName = fmt.Sprintf("HTTP %s route not found", request.Method)
 			}

instrumentation/github.com/labstack/echo/otelecho/test/echo_test.go

@@ -16,12 +16,13 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho"
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/codes"
 	"go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/sdk/trace/tracetest"
 
+	"go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho"
+
 	"go.opentelemetry.io/otel/attribute"
 	oteltrace "go.opentelemetry.io/otel/trace"
 )
@@ -202,3 +203,50 @@ func TestErrorNotSwallowedByMiddleware(t *testing.T) {
 	err := h(c)
 	assert.Equal(t, assert.AnError, err)
 }
+
+func TestSpanNameFormatter(t *testing.T) {
+	imsb := tracetest.NewInMemoryExporter()
+	otel.SetTracerProvider(trace.NewTracerProvider(
+		trace.WithSyncer(imsb),
+	))
+
+	tests := []struct {
+		name      string
+		formatter otelecho.SpanNameFormatter
+		expected  string
+	}{
+		{
+			name:      "default",
+			formatter: nil,
+			expected:  "/user/:id",
+		},
+		{
+			name: "custom",
+			formatter: func(c echo.Context) string {
+				return "custom " + c.Path()
+			},
+			expected: "custom /user/:id",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			defer imsb.Reset()
+
+			router := echo.New()
+			router.Use(otelecho.Middleware("foobar", otelecho.WithSpanNameFormatter(test.formatter)))
+			router.GET("/user/:id", func(c echo.Context) error {
+				return c.NoContent(http.StatusOK)
+			})
+
+			r := httptest.NewRequest("GET", "/user/123", nil)
+			w := httptest.NewRecorder()
+
+			router.ServeHTTP(w, r)
+
+			spans := imsb.GetSpans()
+			assert.Len(t, spans, 1)
+			assert.Equal(t, test.expected, spans[0].Name)
+		})
+	}
+}