embed: Begin refactor to use clearer paths

internal/fsx/open.go

@@ -0,0 +1,31 @@
+package fsx
+
+import "io/fs"
+
+// OpenFS opens the named file in filesystem.
+// If opening the file results in an error, returns [ErrFile].
+func OpenFS(name string, fsys fs.FS) fs.File {
+	file, err := fsys.Open(name)
+	if err != nil {
+		return ErrFile{Err: err}
+	}
+	return file
+}
+
+// ErrFile implements a no-op [fs.File].
+//
+// Every operation will return an underlying error
+type ErrFile struct {
+	Err error
+}
+
+func (err ErrFile) Stat() (fs.FileInfo, error) {
+	return nil, err.Err
+}
+func (err ErrFile) Read([]byte) (int, error) {
+	return 0, err.Err
+}
+
+func (err ErrFile) Close() error {
+	return err.Err
+}