feat: support embed file system to serve files in rest (#4253)

rest/internal/fileserver/filehandler.go

@@ -5,8 +5,9 @@ import (
 	"strings"
 )
 
-func Middleware(path, dir string) func(http.HandlerFunc) http.HandlerFunc {
-	fileServer := http.FileServer(http.Dir(dir))
+// Middleware returns a middleware that serves files from the given file system.
+func Middleware(path string, fs http.FileSystem) func(http.HandlerFunc) http.HandlerFunc {
+	fileServer := http.FileServer(fs)
 	pathWithTrailSlash := ensureTrailingSlash(path)
 	pathWithoutTrailSlash := ensureNoTrailingSlash(path)
 

rest/internal/fileserver/filehandler_test.go

@@ -44,7 +44,7 @@ func TestMiddleware(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			middleware := Middleware(tt.path, tt.dir)
+			middleware := Middleware(tt.path, http.Dir(tt.dir))
 			nextHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				w.WriteHeader(http.StatusNotFound)
 			})

rest/server.go

@@ -172,9 +172,9 @@ func WithCustomCors(middlewareFn func(header http.Header), notAllowedFn func(htt
 }
 
 // WithFileServer returns a RunOption to serve files from given dir with given path.
-func WithFileServer(path, dir string) RunOption {
+func WithFileServer(path string, fs http.FileSystem) RunOption {
 	return func(server *Server) {
-		server.router = newFileServingRouter(server.router, path, dir)
+		server.router = newFileServingRouter(server.router, path, fs)
 	}
 }
 
@@ -351,10 +351,10 @@ type fileServingRouter struct {
 	middleware Middleware
 }
 
-func newFileServingRouter(router httpx.Router, path, dir string) httpx.Router {
+func newFileServingRouter(router httpx.Router, path string, fs http.FileSystem) httpx.Router {
 	return &fileServingRouter{
 		Router:     router,
-		middleware: fileserver.Middleware(path, dir),
+		middleware: fileserver.Middleware(path, fs),
 	}
 }
 

rest/server_test.go

@@ -2,8 +2,10 @@ package rest
 
 import (
 	"crypto/tls"
+	"embed"
 	"fmt"
 	"io"
+	"io/fs"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -21,6 +23,11 @@ import (
 	"github.com/zeromicro/go-zero/rest/router"
 )
 
+const (
+	exampleContent = "example content"
+	sampleContent  = "sample content"
+)
+
 func TestNewServer(t *testing.T) {
 	logtest.Discard(t)
 
@@ -199,7 +206,7 @@ func TestWithFileServerMiddleware(t *testing.T) {
 			dir:             "./testdata",
 			requestPath:     "/assets/example.txt",
 			expectedStatus:  http.StatusOK,
-			expectedContent: "example content",
+			expectedContent: exampleContent,
 		},
 		{
 			name:           "Pass through non-matching path",
@@ -214,13 +221,13 @@ func TestWithFileServerMiddleware(t *testing.T) {
 			dir:             "testdata",
 			requestPath:     "/static/sample.txt",
 			expectedStatus:  http.StatusOK,
-			expectedContent: "sample content",
+			expectedContent: sampleContent,
 		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			server := MustNewServer(RestConf{}, WithFileServer(tt.path, tt.dir))
+			server := MustNewServer(RestConf{}, WithFileServer(tt.path, http.Dir(tt.dir)))
 			req := httptest.NewRequest(http.MethodGet, tt.requestPath, nil)
 			rr := httptest.NewRecorder()
 
@@ -688,3 +695,18 @@ Port: 54321
 		})
 	}
 }
+
+//go:embed testdata
+var content embed.FS
+
+func TestServerEmbedFileSystem(t *testing.T) {
+	filesys, err := fs.Sub(content, "testdata")
+	assert.NoError(t, err)
+
+	server := MustNewServer(RestConf{}, WithFileServer("/assets", http.FS(filesys)))
+	req, err := http.NewRequest(http.MethodGet, "/assets/sample.txt", http.NoBody)
+	assert.Nil(t, err)
+	rr := httptest.NewRecorder()
+	server.ServeHTTP(rr, req)
+	assert.Equal(t, sampleContent, rr.Body.String())
+}