feat: enhance static file serving capabilities

- Add documentation for serving local files and embedded folders in README.md
- Add new example code for serving embedded folders in Go
- Create new `embed_folder.go` file with functions to serve embedded folders
- Create new `embed_folder_test.go` file with tests for serving embedded folders
- Add HTML template files for embedded server example
- Rename `static.go` to `local_file.go` and remove unused code
- Create new `local_file_test.go` file with tests for serving local files
- Create new `serve.go` file with middleware handler for serving static files
- Rename `static_test.go` to `serve_test.go` and refactor test functions
- Remove redundant test case `TestListIndex` from `serve_test.go`

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

README.md

@@ -27,6 +27,8 @@ import "github.com/gin-contrib/static"
 
 See the [example](_example)
 
+#### Serve local file
+
 ```go
 package main
 
@@ -48,6 +50,39 @@ func main() {
     c.String(200, "test")
   })
   // Listen and Server in 0.0.0.0:8080
+  r.Run(":8080")
+}
+```
+
+#### Serve embed folder
+
+```go
+package main
+
+import (
+  "embed"
+  "fmt"
+  "net/http"
+
+  "github.com/gin-contrib/static"
+  "github.com/gin-gonic/gin"
+)
+
+//go:embed data
+var server embed.FS
+
+func main() {
+  r := gin.Default()
+  r.Use(static.Serve("/", static.EmbedFolder(server, "data/server")))
+  r.GET("/ping", func(c *gin.Context) {
+    c.String(200, "test")
+  })
+  r.NoRoute(func(c *gin.Context) {
+    fmt.Printf("%s doesn't exists, redirect on /\n", c.Request.URL.Path)
+    c.Redirect(http.StatusMovedPermanently, "/")
+  })
+  // Listen and Server in 0.0.0.0:8080
+  r.Run(":8080")
   if err := r.Run(":8080"); err != nil {
     log.Fatal(err)
   }

embed_folder.go

@@ -0,0 +1,27 @@
+package static
+
+import (
+	"embed"
+	"io/fs"
+	"log"
+	"net/http"
+)
+
+type embedFileSystem struct {
+	http.FileSystem
+}
+
+func (e embedFileSystem) Exists(prefix string, path string) bool {
+	_, err := e.Open(path)
+	return err == nil
+}
+
+func EmbedFolder(fsEmbed embed.FS, targetPath string) ServeFileSystem {
+	fsys, err := fs.Sub(fsEmbed, targetPath)
+	if err != nil {
+		log.Fatalf("static.EmbedFolder - Invalid targetPath value - %s", err)
+	}
+	return embedFileSystem{
+		FileSystem: http.FS(fsys),
+	}
+}

embed_folder_test.go

@@ -0,0 +1,40 @@
+package static
+
+import (
+	"embed"
+	"fmt"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+)
+
+//go:embed test/data/server
+var server embed.FS
+
+var embedTests = []struct {
+	targetURL string // input
+	httpCode  int    // expected http code
+	httpBody  string // expected http body
+	name      string // test name
+}{
+	{"/404.html", 301, "<a href=\"/\">Moved Permanently</a>.\n\n", "Unknown file"},
+	{"/", 200, "<h1>Hello Embed</h1>", "Root"},
+	{"/index.html", 301, "", "Root by file name automatic redirect"},
+	{"/static.html", 200, "<h1>Hello Gin Static</h1>", "Other file"},
+}
+
+func TestEmbedFolder(t *testing.T) {
+	router := gin.New()
+	router.Use(Serve("/", EmbedFolder(server, "test/data/server")))
+	router.NoRoute(func(c *gin.Context) {
+		fmt.Printf("%s doesn't exists, redirect on /\n", c.Request.URL.Path)
+		c.Redirect(301, "/")
+	})
+
+	for _, tt := range embedTests {
+		w := PerformRequest(router, "GET", tt.targetURL)
+		assert.Equal(t, tt.httpCode, w.Code, tt.name)
+		assert.Equal(t, tt.httpBody, w.Body.String(), tt.name)
+	}
+}

example/embed/data/server/index.html

@@ -0,0 +1 @@
+<h1>Hello Embed</h1>

example/embed/example.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"embed"
+	"fmt"
+	"net/http"
+
+	"github.com/gin-contrib/static"
+	"github.com/gin-gonic/gin"
+)
+
+//go:embed data
+var server embed.FS
+
+func main() {
+	r := gin.Default()
+	r.Use(static.Serve("/", static.EmbedFolder(server, "data/server")))
+	r.GET("/ping", func(c *gin.Context) {
+		c.String(200, "test")
+	})
+	r.NoRoute(func(c *gin.Context) {
+		fmt.Printf("%s doesn't exists, redirect on /\n", c.Request.URL.Path)
+		c.Redirect(http.StatusMovedPermanently, "/")
+	})
+	// Listen and Server in 0.0.0.0:8080
+	r.Run(":8080")
+}

static.go → local_file.go

@@ -11,11 +11,6 @@ import (
 
 const INDEX = "index.html"
 
-type ServeFileSystem interface {
-	http.FileSystem
-	Exists(prefix string, path string) bool
-}
-
 type localFileSystem struct {
 	http.FileSystem
 	root    string
@@ -50,21 +45,3 @@ func (l *localFileSystem) Exists(prefix string, filepath string) bool {
 	}
 	return false
 }
-
-func ServeRoot(urlPrefix, root string) gin.HandlerFunc {
-	return Serve(urlPrefix, LocalFile(root, false))
-}
-
-// Static returns a middleware handler that serves static files in the given directory.
-func Serve(urlPrefix string, fs ServeFileSystem) gin.HandlerFunc {
-	fileserver := http.FileServer(fs)
-	if urlPrefix != "" {
-		fileserver = http.StripPrefix(urlPrefix, fileserver)
-	}
-	return func(c *gin.Context) {
-		if fs.Exists(urlPrefix, c.Request.URL.Path) {
-			fileserver.ServeHTTP(c.Writer, c.Request)
-			c.Abort()
-		}
-	}
-}

local_file_test.go

@@ -0,0 +1,34 @@
+package static
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLocalFile(t *testing.T) {
+	// SETUP file
+	testRoot, _ := os.Getwd()
+	f, err := ioutil.TempFile(testRoot, "")
+	if err != nil {
+		t.Error(err)
+	}
+	defer os.Remove(f.Name())
+	f.WriteString("Gin Web Framework")
+	f.Close()
+
+	dir, filename := filepath.Split(f.Name())
+	router := gin.New()
+	router.Use(Serve("/", LocalFile(dir, true)))
+
+	w := PerformRequest(router, "GET", "/"+filename)
+	assert.Equal(t, w.Code, 200)
+	assert.Equal(t, w.Body.String(), "Gin Web Framework")
+
+	w = PerformRequest(router, "GET", "/")
+	assert.Contains(t, w.Body.String(), `<a href="`+filename)
+}

serve.go

@@ -0,0 +1,30 @@
+package static
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+type ServeFileSystem interface {
+	http.FileSystem
+	Exists(prefix string, path string) bool
+}
+
+func ServeRoot(urlPrefix, root string) gin.HandlerFunc {
+	return Serve(urlPrefix, LocalFile(root, false))
+}
+
+// Serve returns a middleware handler that serves static files in the given directory.
+func Serve(urlPrefix string, fs ServeFileSystem) gin.HandlerFunc {
+	fileserver := http.FileServer(fs)
+	if urlPrefix != "" {
+		fileserver = http.StripPrefix(urlPrefix, fileserver)
+	}
+	return func(c *gin.Context) {
+		if fs.Exists(urlPrefix, c.Request.URL.Path) {
+			fileserver.ServeHTTP(c.Writer, c.Request)
+			c.Abort()
+		}
+	}
+}

static_test.go → serve_test.go

@@ -15,7 +15,7 @@ import (
 )
 
 //nolint:unparam
-func performRequest(r http.Handler, method, path string) *httptest.ResponseRecorder {
+func PerformRequest(r http.Handler, method, path string) *httptest.ResponseRecorder {
 	req, _ := http.NewRequestWithContext(context.Background(), method, path, nil)
 	w := httptest.NewRecorder()
 	r.ServeHTTP(w, req)
@@ -46,19 +46,19 @@ func TestEmptyDirectory(t *testing.T) {
 	router.GET("/"+filename, func(c *gin.Context) {
 		c.String(http.StatusOK, "this is not printed")
 	})
-	w := performRequest(router, "GET", "/")
-	assert.Equal(t, w.Code, http.StatusOK)
+	w := PerformRequest(router, "GET", "/")
+	assert.Equal(t, w.Code, 200)
 	assert.Equal(t, w.Body.String(), "index")
 
-	w = performRequest(router, "GET", "/"+filename)
-	assert.Equal(t, w.Code, http.StatusOK)
+	w = PerformRequest(router, "GET", "/"+filename)
+	assert.Equal(t, w.Code, 200)
 	assert.Equal(t, w.Body.String(), "Gin Web Framework")
 
-	w = performRequest(router, "GET", "/"+filename+"a")
+	w = PerformRequest(router, "GET", "/"+filename+"a")
 	assert.Equal(t, w.Code, 404)
 
-	w = performRequest(router, "GET", "/a")
-	assert.Equal(t, w.Code, http.StatusOK)
+	w = PerformRequest(router, "GET", "/a")
+	assert.Equal(t, w.Code, 200)
 	assert.Equal(t, w.Body.String(), "a")
 
 	router2 := gin.New()
@@ -67,24 +67,24 @@ func TestEmptyDirectory(t *testing.T) {
 		c.String(http.StatusOK, "this is printed")
 	})
 
-	w = performRequest(router2, "GET", "/")
+	w = PerformRequest(router2, "GET", "/")
 	assert.Equal(t, w.Code, 404)
 
-	w = performRequest(router2, "GET", "/static")
+	w = PerformRequest(router2, "GET", "/static")
 	assert.Equal(t, w.Code, 404)
 	router2.GET("/static", func(c *gin.Context) {
 		c.String(http.StatusOK, "index")
 	})
 
-	w = performRequest(router2, "GET", "/static")
-	assert.Equal(t, w.Code, http.StatusOK)
+	w = PerformRequest(router2, "GET", "/static")
+	assert.Equal(t, w.Code, 200)
 
-	w = performRequest(router2, "GET", "/"+filename)
-	assert.Equal(t, w.Code, http.StatusOK)
+	w = PerformRequest(router2, "GET", "/"+filename)
+	assert.Equal(t, w.Code, 200)
 	assert.Equal(t, w.Body.String(), "this is printed")
 
-	w = performRequest(router2, "GET", "/static/"+filename)
-	assert.Equal(t, w.Code, http.StatusOK)
+	w = PerformRequest(router2, "GET", "/static/"+filename)
+	assert.Equal(t, w.Code, 200)
 	assert.Equal(t, w.Body.String(), "Gin Web Framework")
 }
 
@@ -104,33 +104,10 @@ func TestIndex(t *testing.T) {
 	router := gin.New()
 	router.Use(ServeRoot("/", dir))
 
-	w := performRequest(router, "GET", "/"+filename)
+	w := PerformRequest(router, "GET", "/"+filename)
 	assert.Equal(t, w.Code, 301)
 
-	w = performRequest(router, "GET", "/")
-	assert.Equal(t, w.Code, http.StatusOK)
+	w = PerformRequest(router, "GET", "/")
+	assert.Equal(t, w.Code, 200)
 	assert.Equal(t, w.Body.String(), "index")
 }
-
-func TestListIndex(t *testing.T) {
-	// SETUP file
-	testRoot, _ := os.Getwd()
-	f, err := ioutil.TempFile(testRoot, "")
-	if err != nil {
-		t.Error(err)
-	}
-	defer os.Remove(f.Name())
-	_, _ = f.WriteString("Gin Web Framework")
-	f.Close()
-
-	dir, filename := filepath.Split(f.Name())
-	router := gin.New()
-	router.Use(Serve("/", LocalFile(dir, true)))
-
-	w := performRequest(router, "GET", "/"+filename)
-	assert.Equal(t, w.Code, http.StatusOK)
-	assert.Equal(t, w.Body.String(), "Gin Web Framework")
-
-	w = performRequest(router, "GET", "/")
-	assert.Contains(t, w.Body.String(), `<a href="`+filename)
-}

test/data/server/index.html

@@ -0,0 +1 @@
+<h1>Hello Embed</h1>

test/data/server/static.html

@@ -0,0 +1 @@
+<h1>Hello Gin Static</h1>