Merge pull request #1 from jvcoutinho/feature/result-package

Result package
jvcoutinho · May 6, 2023 · b9f3fc9 · b9f3fc9
2 parents d4adc47 + 698e7aa
commit b9f3fc9
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Showing 5 changed files with 106 additions and 32 deletions.
diff --git a/result.go b/result.go
@@ -0,0 +1,9 @@
+package lit
+
+// Result of an HTTP request.
+//
+// Use the result package in order to produce Result implementations.
+type Result interface {
+	// Write writes the result into the HTTP response managed by ctx.
+	Write(ctx *Context)
+}
diff --git a/result/result.go b/result/result.go
@@ -0,0 +1,16 @@
+// Package result contains functions that return responses for incoming requests.
+package result
+
+import (
+	"net/http"
+)
+
+// Ok responds the request with Status Code 200 (OK).
+func Ok() *TerminalResponse {
+	return newTerminalResponse(http.StatusOK, nil)
+}
+
+// BadRequest responds the request with Status Code 400 (OK).
+func BadRequest() *TerminalResponse {
+	return newTerminalResponse(http.StatusBadRequest, nil)
+}
diff --git a/result/terminal_response.go b/result/terminal_response.go
@@ -0,0 +1,37 @@
+package result
+
+import (
+	"github.com/jvcoutinho/lit"
+)
+
+// TerminalResponse writes a single chunk of bytes into the response and closes the request.
+type TerminalResponse struct {
+	statusCode int
+	body       []byte
+	header     map[string]string
+}
+
+func newTerminalResponse(statusCode int, body []byte) *TerminalResponse {
+	return &TerminalResponse{statusCode: statusCode, body: body}
+}
+
+func (r *TerminalResponse) AddHeader(key string, value string) {
+	if r.header == nil {
+		r.header = make(map[string]string)
+	}
+
+	r.header[key] = value
+}
+
+func (r *TerminalResponse) Write(ctx *lit.Context) {
+	responseWriter := ctx.ResponseWriter
+
+	header := responseWriter.Header()
+	for key, value := range r.header {
+		header.Set(key, value)
+	}
+
+	responseWriter.WriteHeader(r.statusCode)
+
+	_, _ = responseWriter.Write(r.body)
+}
diff --git a/router.go b/router.go
@@ -10,7 +10,7 @@ import (
 const DefaultReadHeaderTimeout = 3 * time.Second
 
 // HandleFunc is a function that handles requests.
-type HandleFunc func(ctx *Context)
+type HandleFunc func(ctx *Context) Result
 
 // Router manages API routes.
 //
@@ -62,7 +62,11 @@ func (r *Router) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	ctx := newContext(writer, request)
 	ctx.setArguments(match.Parameters)
 
-	handler(ctx)
+	result := handler(ctx)
+
+	if result != nil {
+		result.Write(ctx)
+	}
 }
 
 // Server this router uses for listening and serving requests.

diff --git a/router_test.go b/router_test.go
@@ -19,6 +19,8 @@ func TestRouter_Handle(t *testing.T) {
 		Handler lit.HandleFunc
 	}
 
+	emptyHandler := func(ctx *lit.Context) lit.Result { return nil }
+
 	tests := []struct {
 		name string
 
@@ -31,124 +33,124 @@ func TestRouter_Handle(t *testing.T) {
 		{
 			name: "RouteDoesNotExist_SameMethod",
 			currentRoutes: []route{
-				{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users/owner", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users/owner", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        false,
 			expectedError: "",
 		},
 		{
 			name: "RouteDoesNotExist_SamePattern",
 			currentRoutes: []route{
-				{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users", Method: http.MethodPost, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users", Method: http.MethodPost, Handler: emptyHandler},
 			panics:        false,
 			expectedError: "",
 		},
 		{
 			name: "RouteDoesNotExist_Subpattern",
 			currentRoutes: []route{
-				{Pattern: "/users/:user_id", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users/:user_id", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        false,
 			expectedError: "",
 		},
 		{
 			name: "RouteDoesNotExist_Superpattern",
 			currentRoutes: []route{
-				{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users/:user_id", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users/:user_id", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        false,
 			expectedError: "",
 		},
 		{
 			name: "RouteAlreadyExists",
 			currentRoutes: []route{
-				{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_DifferentMethodCase",
 			currentRoutes: []route{
-				{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users", Method: "get", Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users", Method: "get", Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_MissingLeadingSlash",
 			currentRoutes: []route{
-				{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "users", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_PresentTrailingSlash",
 			currentRoutes: []route{
-				{Pattern: "/users", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "users/", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "users/", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_MultiplePaths",
 			currentRoutes: []route{
-				{Pattern: "/users/owner", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users/owner", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users/owner", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users/owner", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users/owner has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_MultiplePaths_MissingLeadingSlash",
 			currentRoutes: []route{
-				{Pattern: "/users/owner", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users/owner", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "users/owner", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "users/owner", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users/owner has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_MultiplePaths_PresentTrailingSlash",
 			currentRoutes: []route{
-				{Pattern: "/users/owner", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users/owner", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "users/owner/", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "users/owner/", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users/owner has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_MultiplePaths_DifferentArguments",
 			currentRoutes: []route{
-				{Pattern: "/users/:id", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users/:id", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users/:user_id", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users/:user_id", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users/:user_id has been already defined",
 		},
 		{
 			name: "RouteAlreadyExists_MultiplePaths_DifferentArguments_ArgumentInMiddle",
 			currentRoutes: []route{
-				{Pattern: "/users/:user_id/items", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+				{Pattern: "/users/:user_id/items", Method: http.MethodGet, Handler: emptyHandler},
 			},
-			routeToHandle: route{Pattern: "/users/:id/items", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users/:id/items", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "GET /users/:id/items has been already defined",
 		},
 		{
 			name:          "InvalidRoute_DuplicateArgument",
 			currentRoutes: nil,
-			routeToHandle: route{Pattern: "/users/:id/items/:id", Method: http.MethodGet, Handler: func(ctx *lit.Context) {}},
+			routeToHandle: route{Pattern: "/users/:id/items/:id", Method: http.MethodGet, Handler: emptyHandler},
 			panics:        true,
 			expectedError: "a pattern can not contain two arguments with the same name (:id)",
 		},
@@ -190,8 +192,12 @@ func TestRouter_ServeHTTP(t *testing.T) {
 		Handler lit.HandleFunc
 	}
 
-	okHandler := func(_ *lit.Context) {}
-	notFoundHandler := func(ctx *lit.Context) { http.NotFound(ctx.ResponseWriter, ctx.Request) }
+	okHandler := func(_ *lit.Context) lit.Result { return nil }
+	notFoundHandler := func(ctx *lit.Context) lit.Result {
+		http.NotFound(ctx.ResponseWriter, ctx.Request)
+
+		return nil
+	}
 
 	tests := []struct {
 		name string
@@ -352,10 +358,12 @@ func TestRouter_ServeHTTP(t *testing.T) {
 			router := lit.NewRouter()
 
 			for _, currentRoute := range test.currentRoutes {
-				router.Handle(currentRoute.Pattern, currentRoute.Method, func(ctx *lit.Context) {
+				router.Handle(currentRoute.Pattern, currentRoute.Method, func(ctx *lit.Context) lit.Result {
 					require.Equal(t, test.expectedArguments, ctx.URIArguments())
 
 					currentRoute.Handler(ctx)
+
+					return nil
 				})
 			}