Move OnlyHTMLFS to internal and add test

docs/doc.md

@@ -1351,6 +1351,8 @@ func main() {
   router := gin.Default()
   router.LoadHTMLGlob("templates/*")
   //router.LoadHTMLFiles("templates/template1.html", "templates/template2.html")
+  //router.LoadHTMLFS(http.Dir("templates"), "template1.html", "template2.html")
+  //or
   //router.LoadHTMLFS(http.FS(templates), "templates/template1.html", "templates/template2.html")
   router.GET("/index", func(c *gin.Context) {
     c.HTML(http.StatusOK, "index.tmpl", gin.H{

fs.go

@@ -5,7 +5,6 @@
 package gin
 
 import (
-	"io/fs"
 	"net/http"
 	"os"
 )
@@ -26,22 +25,6 @@ func (o OnlyFilesFS) Open(name string) (http.File, error) {
 	return neutralizedReaddirFile{f}, nil
 }
 
-// OnlyHTMLFS implements an [fs.FS].
-type OnlyHTMLFS struct {
-	FileSystem http.FileSystem
-}
-
-// Open passes `Open` to the upstream implementation and return an [fs.File].
-func (o OnlyHTMLFS) Open(name string) (fs.File, error) {
-	f, err := o.FileSystem.Open(name)
-
-	if err != nil {
-		return nil, err
-	}
-
-	return fs.File(f), nil
-}
-
 // neutralizedReaddirFile wraps http.File with a specific implementation of `Readdir`.
 type neutralizedReaddirFile struct {
 	http.File

fs_test.go

@@ -48,36 +48,6 @@ func TestOnlyFilesFS_Open_err(t *testing.T) {
 	assert.Nil(t, file)
 }
 
-func TestOnlyHTMLFS_Open(t *testing.T) {
-	var testFile *os.File
-	mockFS := &mockFileSystem{
-		open: func(name string) (http.File, error) {
-			return testFile, nil
-		},
-	}
-	fs := &OnlyHTMLFS{FileSystem: mockFS}
-
-	file, err := fs.Open("foo")
-
-	require.NoError(t, err)
-	assert.Equal(t, testFile, file)
-}
-
-func TestOnlyHTMLFS_Open_err(t *testing.T) {
-	testError := errors.New("mock")
-	mockFS := &mockFileSystem{
-		open: func(_ string) (http.File, error) {
-			return nil, testError
-		},
-	}
-	fs := &OnlyHTMLFS{FileSystem: mockFS}
-
-	file, err := fs.Open("foo")
-
-	require.ErrorIs(t, err, testError)
-	assert.Nil(t, file)
-}
-
 func Test_neuteredReaddirFile_Readdir(t *testing.T) {
 	n := neutralizedReaddirFile{}
 

gin.go

@@ -16,6 +16,7 @@ import (
 	"sync"
 
 	"github.com/gin-gonic/gin/internal/bytesconv"
+	filesystem "github.com/gin-gonic/gin/internal/fs"
 	"github.com/gin-gonic/gin/render"
 
 	"github.com/quic-go/quic-go/http3"
@@ -289,11 +290,12 @@ func (engine *Engine) LoadHTMLFiles(files ...string) {
 // and associates the result with HTML renderer.
 func (engine *Engine) LoadHTMLFS(fs http.FileSystem, patterns ...string) {
 	if IsDebugging() {
-		engine.HTMLRender = render.HTMLDebug{FS: OnlyHTMLFS{fs}, Patterns: patterns, FuncMap: engine.FuncMap, Delims: engine.delims}
+		engine.HTMLRender = render.HTMLDebug{FileSystem: fs, Patterns: patterns, FuncMap: engine.FuncMap, Delims: engine.delims}
 		return
 	}
 
-	templ := template.Must(template.New("").Delims(engine.delims.Left, engine.delims.Right).Funcs(engine.FuncMap).ParseFS(OnlyHTMLFS{fs}, patterns...))
+	templ := template.Must(template.New("").Delims(engine.delims.Left, engine.delims.Right).Funcs(engine.FuncMap).ParseFS(
+		filesystem.FileSystem{FileSystem: fs}, patterns...))
 	engine.SetHTMLTemplate(templ)
 }
 

gin_test.go

@@ -6,7 +6,6 @@ package gin
 
 import (
 	"crypto/tls"
-	"embed"
 	"fmt"
 	"html/template"
 	"io"
@@ -326,16 +325,15 @@ func TestLoadHTMLFilesFuncMap(t *testing.T) {
 	assert.Equal(t, "Date: 2017/07/01", string(resp))
 }
 
-//go:embed testdata/template/*.tmpl
-var tmplFS embed.FS
+var tmplFS = http.Dir("testdata/template")
 
 func TestLoadHTMLFSTestMode(t *testing.T) {
 	ts := setupHTMLFiles(
 		t,
 		TestMode,
 		false,
 		func(router *Engine) {
-			router.LoadHTMLFS(http.FS(tmplFS), "testdata/template/hello.tmpl", "testdata/template/raw.tmpl")
+			router.LoadHTMLFS(tmplFS, "hello.tmpl", "raw.tmpl")
 		},
 	)
 	defer ts.Close()
@@ -355,7 +353,7 @@ func TestLoadHTMLFSDebugMode(t *testing.T) {
 		DebugMode,
 		false,
 		func(router *Engine) {
-			router.LoadHTMLFS(http.FS(tmplFS), "testdata/template/hello.tmpl", "testdata/template/raw.tmpl")
+			router.LoadHTMLFS(tmplFS, "hello.tmpl", "raw.tmpl")
 		},
 	)
 	defer ts.Close()
@@ -375,7 +373,7 @@ func TestLoadHTMLFSReleaseMode(t *testing.T) {
 		ReleaseMode,
 		false,
 		func(router *Engine) {
-			router.LoadHTMLFS(http.FS(tmplFS), "testdata/template/hello.tmpl", "testdata/template/raw.tmpl")
+			router.LoadHTMLFS(tmplFS, "hello.tmpl", "raw.tmpl")
 		},
 	)
 	defer ts.Close()
@@ -395,7 +393,7 @@ func TestLoadHTMLFSUsingTLS(t *testing.T) {
 		TestMode,
 		true,
 		func(router *Engine) {
-			router.LoadHTMLFS(http.FS(tmplFS), "testdata/template/hello.tmpl", "testdata/template/raw.tmpl")
+			router.LoadHTMLFS(tmplFS, "hello.tmpl", "raw.tmpl")
 		},
 	)
 	defer ts.Close()
@@ -422,7 +420,7 @@ func TestLoadHTMLFSFuncMap(t *testing.T) {
 		TestMode,
 		false,
 		func(router *Engine) {
-			router.LoadHTMLFS(http.FS(tmplFS), "testdata/template/hello.tmpl", "testdata/template/raw.tmpl")
+			router.LoadHTMLFS(tmplFS, "hello.tmpl", "raw.tmpl")
 		},
 	)
 	defer ts.Close()

internal/fs/fs.go

@@ -0,0 +1,22 @@
+package fs
+
+import (
+	"io/fs"
+	"net/http"
+)
+
+// FileSystem implements an [fs.FS].
+type FileSystem struct {
+	http.FileSystem
+}
+
+// Open passes `Open` to the upstream implementation and return an [fs.File].
+func (o FileSystem) Open(name string) (fs.File, error) {
+	f, err := o.FileSystem.Open(name)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return fs.File(f), nil
+}

internal/fs/fs_test.go

@@ -0,0 +1,49 @@
+package fs
+
+import (
+	"errors"
+	"net/http"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type mockFileSystem struct {
+	open func(name string) (http.File, error)
+}
+
+func (m *mockFileSystem) Open(name string) (http.File, error) {
+	return m.open(name)
+}
+
+func TesFileSystem_Open(t *testing.T) {
+	var testFile *os.File
+	mockFS := &mockFileSystem{
+		open: func(name string) (http.File, error) {
+			return testFile, nil
+		},
+	}
+	fs := &FileSystem{mockFS}
+
+	file, err := fs.Open("foo")
+
+	require.NoError(t, err)
+	assert.Equal(t, testFile, file)
+}
+
+func TestFileSystem_Open_err(t *testing.T) {
+	testError := errors.New("mock")
+	mockFS := &mockFileSystem{
+		open: func(_ string) (http.File, error) {
+			return nil, testError
+		},
+	}
+	fs := &FileSystem{mockFS}
+
+	file, err := fs.Open("foo")
+
+	require.ErrorIs(t, err, testError)
+	assert.Nil(t, file)
+}

render/html.go

@@ -6,8 +6,9 @@ package render
 
 import (
 	"html/template"
-	"io/fs"
 	"net/http"
+
+	"github.com/gin-gonic/gin/internal/fs"
 )
 
 // Delims represents a set of Left and Right delimiters for HTML template rendering.
@@ -32,12 +33,12 @@ type HTMLProduction struct {
 
 // HTMLDebug contains template delims and pattern and function with file list.
 type HTMLDebug struct {
-	Files    []string
-	Glob     string
-	FS       fs.FS
-	Patterns []string
-	Delims   Delims
-	FuncMap  template.FuncMap
+	Files      []string
+	Glob       string
+	FileSystem http.FileSystem
+	Patterns   []string
+	Delims     Delims
+	FuncMap    template.FuncMap
 }
 
 // HTML contains template reference and its name with given interface object.
@@ -76,8 +77,9 @@ func (r HTMLDebug) loadTemplate() *template.Template {
 	if r.Glob != "" {
 		return template.Must(template.New("").Delims(r.Delims.Left, r.Delims.Right).Funcs(r.FuncMap).ParseGlob(r.Glob))
 	}
-	if r.FS != nil && len(r.Patterns) > 0 {
-		return template.Must(template.New("").Delims(r.Delims.Left, r.Delims.Right).Funcs(r.FuncMap).ParseFS(r.FS, r.Patterns...))
+	if r.FileSystem != nil && len(r.Patterns) > 0 {
+		return template.Must(template.New("").Delims(r.Delims.Left, r.Delims.Right).Funcs(r.FuncMap).ParseFS(
+			fs.FileSystem{FileSystem: r.FileSystem}, r.Patterns...))
 	}
 	panic("the HTML debug render was created without files or glob pattern or file system with patterns")
 }

render/render_test.go

@@ -489,10 +489,12 @@ func TestRenderHTMLTemplateEmptyName(t *testing.T) {
 func TestRenderHTMLDebugFiles(t *testing.T) {
 	w := httptest.NewRecorder()
 	htmlRender := HTMLDebug{
-		Files:   []string{"../testdata/template/hello.tmpl"},
-		Glob:    "",
-		Delims:  Delims{Left: "{[{", Right: "}]}"},
-		FuncMap: nil,
+		Files:      []string{"../testdata/template/hello.tmpl"},
+		Glob:       "",
+		FileSystem: nil,
+		Patterns:   nil,
+		Delims:     Delims{Left: "{[{", Right: "}]}"},
+		FuncMap:    nil,
 	}
 	instance := htmlRender.Instance("hello.tmpl", map[string]any{
 		"name": "thinkerou",
@@ -508,10 +510,33 @@ func TestRenderHTMLDebugFiles(t *testing.T) {
 func TestRenderHTMLDebugGlob(t *testing.T) {
 	w := httptest.NewRecorder()
 	htmlRender := HTMLDebug{
-		Files:   nil,
-		Glob:    "../testdata/template/hello*",
-		Delims:  Delims{Left: "{[{", Right: "}]}"},
-		FuncMap: nil,
+		Files:      nil,
+		Glob:       "../testdata/template/hello*",
+		FileSystem: nil,
+		Patterns:   nil,
+		Delims:     Delims{Left: "{[{", Right: "}]}"},
+		FuncMap:    nil,
+	}
+	instance := htmlRender.Instance("hello.tmpl", map[string]any{
+		"name": "thinkerou",
+	})
+
+	err := instance.Render(w)
+
+	require.NoError(t, err)
+	assert.Equal(t, "<h1>Hello thinkerou</h1>", w.Body.String())
+	assert.Equal(t, "text/html; charset=utf-8", w.Header().Get("Content-Type"))
+}
+
+func TestRenderHTMLDebugFS(t *testing.T) {
+	w := httptest.NewRecorder()
+	htmlRender := HTMLDebug{
+		Files:      nil,
+		Glob:       "",
+		FileSystem: http.Dir("../testdata/template"),
+		Patterns:   []string{"hello.tmpl"},
+		Delims:     Delims{Left: "{[{", Right: "}]}"},
+		FuncMap:    nil,
 	}
 	instance := htmlRender.Instance("hello.tmpl", map[string]any{
 		"name": "thinkerou",
@@ -526,10 +551,12 @@ func TestRenderHTMLDebugGlob(t *testing.T) {
 
 func TestRenderHTMLDebugPanics(t *testing.T) {
 	htmlRender := HTMLDebug{
-		Files:   nil,
-		Glob:    "",
-		Delims:  Delims{"{{", "}}"},
-		FuncMap: nil,
+		Files:      nil,
+		Glob:       "",
+		FileSystem: nil,
+		Patterns:   nil,
+		Delims:     Delims{"{{", "}}"},
+		FuncMap:    nil,
 	}
 	assert.Panics(t, func() { htmlRender.Instance("", nil) })
 }