fix #6: add more tests, add Tracer and Stack description

http/middleware/middleware.go

@@ -2,11 +2,13 @@ package middleware
 
 import "net/http"
 
-// Middleware defines the Handler wrapper.
+// Middleware defines a Handler wrapper.
 type Middleware func(http.Handler) http.Handler
 
-type Stack []Middleware
+// Stack provides the method to wrap a Handler.
+type Stack []func(http.Handler) http.Handler
 
+// Apply wraps the Handler.
 func (stack Stack) Apply(handler http.Handler) http.Handler {
 	for i := len(stack) - 1; i >= 0; i-- {
 		handler = stack[i](handler)

http/middleware/middleware_test.go

@@ -0,0 +1,49 @@
+package middleware_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	. "go.octolab.org/toolkit/protocol/http/middleware"
+)
+
+func TestStack_Apply(t *testing.T) {
+	t.Run("empty stack", func(t *testing.T) {
+		var (
+			calls []int
+			stack Stack
+		)
+		handler := http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
+			calls = append(calls, 1)
+		})
+
+		stack.Apply(handler).ServeHTTP(httptest.NewRecorder(), &http.Request{})
+		assert.Equal(t, []int{1}, calls)
+	})
+	t.Run("full stack", func(t *testing.T) {
+		var calls []int
+		stack := Stack{
+			func(handler http.Handler) http.Handler {
+				return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+					calls = append(calls, 1)
+					handler.ServeHTTP(rw, req)
+				})
+			},
+			func(handler http.Handler) http.Handler {
+				return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+					calls = append(calls, 2)
+					handler.ServeHTTP(rw, req)
+				})
+			},
+		}
+		handler := http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
+			calls = append(calls, 3)
+		})
+
+		stack.Apply(handler).ServeHTTP(httptest.NewRecorder(), &http.Request{})
+		assert.Equal(t, []int{1, 2, 3}, calls)
+	})
+}

http/middleware/tracer_test.go

@@ -15,10 +15,11 @@ import (
 
 func TestTracer(t *testing.T) {
 	var spy bool
-	middleware := Tracer(1, func(tracer *tracer.Trace) {
+	logger := func(tracer *tracer.Trace) {
 		assert.Contains(t, tracer.String(), "call middleware_test.TestTracer.func2")
 		spy = true
-	})
+	}
+	middleware := Tracer(1, logger)
 
 	var handler http.Handler
 	handler = http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
@@ -27,11 +28,18 @@ func TestTracer(t *testing.T) {
 	})
 	handler = middleware(handler)
 
-	ctx, cancel := context.WithCancel(context.Background())
-	handler.ServeHTTP(httptest.NewRecorder(), (&http.Request{}).WithContext(ctx))
-	assert.False(t, spy)
+	t.Run("without log", func(t *testing.T) {
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		handler.ServeHTTP(httptest.NewRecorder(), (&http.Request{}).WithContext(ctx))
+		assert.False(t, spy)
+	})
+	t.Run("with log", func(t *testing.T) {
+		ctx, cancel := context.WithCancel(context.Background())
+		cancel()
 
-	cancel()
-	handler.ServeHTTP(httptest.NewRecorder(), (&http.Request{}).WithContext(ctx))
-	assert.True(t, spy)
+		handler.ServeHTTP(httptest.NewRecorder(), (&http.Request{}).WithContext(ctx))
+		assert.True(t, spy)
+	})
 }