fileserver struct rather than DefaultServeMux

Author: syntaqx

README.md

@@ -88,6 +88,27 @@ to your `$PATH`, can now be used.
 serve version
 ```
 
+## Using `serve` manually
+
+Serve also exposes a reusable `FileServer` convenience struct, letting you
+easily create your own static file server:
+
+```go
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/syntaqx/serve"
+)
+
+func main() {
+	fs := serve.NewFileServer(".")
+	log.Fatal(http.ListenAndServe(":8080", fs))
+}
+```
+
 ## License
 
 [MIT]: https://opensource.org/licenses/MIT

example/simple/main.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/syntaqx/serve"
+)
+
+func main() {
+	fs := serve.NewFileServer(".")
+	log.Fatal(http.ListenAndServe(":8080", fs))
+}

internal/commands/server.go

@@ -8,17 +8,23 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/syntaqx/serve"
 	"github.com/syntaqx/serve/internal/config"
-	"github.com/syntaqx/serve/internal/router"
+	"github.com/syntaqx/serve/internal/middleware"
 )
 
 // Server implements the static http server command.
 func Server(log *log.Logger, opt config.Flags) error {
-	r := router.NewRouter(log, opt)
+	fs := serve.NewFileServer(opt.Dir)
+
+	fs.Use(middleware.Logger(log))
+	fs.Use(middleware.Recover())
+	fs.Use(middleware.CORS())
+	fs.Use(middleware.NoCache())
 
 	server := &http.Server{
 		Addr:         net.JoinHostPort(opt.Host, strconv.Itoa(opt.Port)),
-		Handler:      r,
+		Handler:      fs,
 		ReadTimeout:  15 * time.Second,
 		WriteTimeout: 15 * time.Second,
 	}

internal/middleware/recover_test.go

@@ -25,5 +25,5 @@ func TestRecover(t *testing.T) {
 	Recover()(testHandler).ServeHTTP(res, req)
 
 	assert.Equal(http.StatusInternalServerError, res.Code)
-	assert.Equal(strings.TrimSpace(res.Body.String()), "[PANIC RECOVERED] test")
+	assert.Equal("[PANIC RECOVERED] test", strings.TrimSpace(res.Body.String()))
 }

internal/router/router.go

@@ -1,2 +1,28 @@
 // Package serve provides a static http server anywhere you need one.
 package serve
+
+import "net/http"
+
+// FileServer implements the http.FileServer.
+type FileServer struct {
+	Handler http.Handler
+}
+
+// NewFileServer initializes a FileServer.
+func NewFileServer(dir string) *FileServer {
+	fs := &FileServer{
+		Handler: http.FileServer(http.Dir(dir)),
+	}
+
+	return fs
+}
+
+// Use wraps the handler with another, middleware style.
+func (fs *FileServer) Use(h func(http.Handler) http.Handler) {
+	fs.Handler = h(fs.Handler)
+}
+
+// ServeHTTP implements the net/http.Handler interface.
+func (fs *FileServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	fs.Handler.ServeHTTP(w, r)
+}

internal/router/router_test.go

@@ -0,0 +1,62 @@
+package serve
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFileServerUse(t *testing.T) {
+	t.Parallel()
+	assert := assert.New(t)
+
+	req, err := http.NewRequest(http.MethodGet, "/", nil)
+	assert.NoError(err)
+	res := httptest.NewRecorder()
+
+	testMiddleware1 := func(next http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			_, _ = w.Write([]byte("start\n"))
+			next.ServeHTTP(w, r)
+		}
+		return http.HandlerFunc(fn)
+	}
+
+	testMiddleware2 := func(next http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			_, _ = w.Write([]byte("end\n"))
+		}
+		return http.HandlerFunc(fn)
+	}
+
+	fs := NewFileServer(".")
+	fs.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Fail()
+	})
+
+	fs.Use(testMiddleware2)
+	fs.Use(testMiddleware1)
+
+	fs.ServeHTTP(res, req)
+
+	assert.Equal("start\nend\n", res.Body.String())
+}
+
+func TestFileServerServeHTTP(t *testing.T) {
+	t.Parallel()
+	assert := assert.New(t)
+
+	req, err := http.NewRequest(http.MethodGet, "/", nil)
+	assert.NoError(err)
+	res := httptest.NewRecorder()
+
+	fs := NewFileServer(".")
+	fs.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = w.Write([]byte("expected"))
+	})
+	fs.ServeHTTP(res, req)
+
+	assert.Equal("expected", res.Body.String())
+}