using path rather than filepath for URL-ish internal expressions

fs.go

@@ -26,13 +26,28 @@ func NewFS(embed fs.ReadDirFS, dir string) FS {
 	}
 }
 
-// Open implements the FS interface.
+// Open opens the named file.
+//
+// When Open returns an error, it should be of type *PathError with the Op
+// field set to "open", the Path field set to name, and the Err field
+// describing the problem.
+//
+// Open should reject attempts to open names that do not satisfy
+// ValidPath(name), returning a *PathError with Err set to ErrInvalid or
+// ErrNotExist.
 func (f FS) Open(name string) (fs.File, error) {
 	if name == "embed.go" {
-		return nil, fs.ErrNotExist
+		return nil, &fs.PathError{
+			Op:   "open",
+			Path: name,
+			Err:  fs.ErrNotExist,
+		}
 	}
 	file, err := f.getFile(name)
 	if name == "." {
+		// NOTE: It always returns the root from the "disk" instead
+		// "embed". However, it could be fine since the the purpose
+		// of buffalo.FS isn't supporting full featured filesystem.
 		return rootFile{file}, err
 	}
 	return file, err

fs_test.go

@@ -48,6 +48,15 @@ func Test_FS_Prioritizes_Disk(t *testing.T) {
 	r.NoError(err)
 
 	r.Equal("This file is on disk.", string(b))
+
+	// should handle slash-separated path for all systems including Windows
+	f, err = fsys.Open("under/sub/subfile")
+	r.NoError(err)
+
+	b, err = io.ReadAll(f)
+	r.NoError(err)
+
+	r.Equal("This file is on disk/sub.", string(b))
 }
 
 func Test_FS_Uses_Embed_If_No_Disk(t *testing.T) {
@@ -63,6 +72,15 @@ func Test_FS_Uses_Embed_If_No_Disk(t *testing.T) {
 	r.NoError(err)
 
 	r.Equal("This file is embedded.", string(b))
+
+	// should handle slash-separated path for all systems including Windows
+	f, err = fsys.Open("under/sub/subfile")
+	r.NoError(err)
+
+	b, err = io.ReadAll(f)
+	r.NoError(err)
+
+	r.Equal("This file is on embedded/sub.", string(b))
 }
 
 func Test_FS_ReadDirFile(t *testing.T) {
@@ -87,11 +105,11 @@ func Test_FS_ReadDirFile(t *testing.T) {
 	r.LessOrEqual(len(entries), 1, "a call to ReadDir must at most return n entries")
 
 	// Second read should return at most 2 files
-	entries, err = dir.ReadDir(2)
+	entries, err = dir.ReadDir(3)
 	r.NoError(err)
 
-	// The actual len will be 2 (file.txt & file2.txt)
-	r.LessOrEqual(len(entries), 2, "a call to ReadDir must at most return n entries")
+	// The actual len will be 2 (file.txt & file2.txt + under/)
+	r.LessOrEqual(len(entries), 3, "a call to ReadDir must at most return n entries")
 
 	// trying to read next 2 files (none left)
 	entries, err = dir.ReadDir(2)

internal/testdata/disk/under/sub/subfile

@@ -0,0 +1 @@
+This file is on disk/sub.

internal/testdata/embedded/under/sub/subfile

@@ -0,0 +1 @@
+This file is on embedded/sub.

render/auto.go

@@ -7,7 +7,6 @@ import (
 	"io"
 	"net/http"
 	"path"
-	"path/filepath"
 	"reflect"
 	"strings"
 
@@ -117,34 +116,34 @@ func (ir htmlAutoRenderer) Render(w io.Writer, data Data) error {
 			}
 
 			if data["method"] == "PUT" {
-				return ir.HTML(filepath.Join(templatePrefix.String(), "edit.html")).Render(w, data)
+				return ir.HTML(path.Join(templatePrefix.String(), "edit.html")).Render(w, data)
 			}
 
-			return ir.HTML(filepath.Join(templatePrefix.String(), "new.html")).Render(w, data)
+			return ir.HTML(path.Join(templatePrefix.String(), "new.html")).Render(w, data)
 		}
 		return nil
 	}
 
 	cp, ok := data["current_path"].(string)
 
 	defCase := func() error {
-		return ir.HTML(filepath.Join(templatePrefix.String(), "index.html")).Render(w, data)
+		return ir.HTML(path.Join(templatePrefix.String(), "index.html")).Render(w, data)
 	}
 
 	if !ok {
 		return defCase()
 	}
 
 	if strings.HasSuffix(cp, "/edit/") {
-		return ir.HTML(filepath.Join(templatePrefix.String(), "edit.html")).Render(w, data)
+		return ir.HTML(path.Join(templatePrefix.String(), "edit.html")).Render(w, data)
 	}
 
 	if strings.HasSuffix(cp, "/new/") {
-		return ir.HTML(filepath.Join(templatePrefix.String(), "new.html")).Render(w, data)
+		return ir.HTML(path.Join(templatePrefix.String(), "new.html")).Render(w, data)
 	}
 
 	if !isPlural {
-		return ir.HTML(filepath.Join(templatePrefix.String(), "show.html")).Render(w, data)
+		return ir.HTML(path.Join(templatePrefix.String(), "show.html")).Render(w, data)
 	}
 
 	return defCase()

render/template_helpers.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"html/template"
 	"io"
+	"path"
 	"path/filepath"
 
 	ht "github.com/gobuffalo/helpers/tags"
@@ -49,7 +50,7 @@ func assetPathFor(file string) string {
 	if filePath == "" || !ok {
 		filePath = file
 	}
-	return filepath.ToSlash(filepath.Join("/assets", filePath))
+	return path.Join("/assets", filePath)
 }
 
 func loadManifest(manifest io.Reader) error {
@@ -59,7 +60,9 @@ func loadManifest(manifest io.Reader) error {
 		return err
 	}
 	for k, v := range m {
-		assetMap.Store(k, v)
+		// I don't think v has backslash but if so, correct them when
+		// creating the map instead using the value in `assetPathFor()`.
+		assetMap.Store(k, filepath.ToSlash(v))
 	}
 	return nil
 }