Update dependencies and vendor (#1761)

vendor/github.com/labstack/echo/v4/echo_fs_go1.16.go

@@ -0,0 +1,145 @@
+//go:build go1.16
+// +build go1.16
+
+package echo
+
+import (
+	"fmt"
+	"io/fs"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type filesystem struct {
+	// Filesystem is file system used by Static and File handlers to access files.
+	// Defaults to os.DirFS(".")
+	//
+	// When dealing with `embed.FS` use `fs := echo.MustSubFS(fs, "rootDirectory") to create sub fs which uses necessary
+	// prefix for directory path. This is necessary as `//go:embed assets/images` embeds files with paths
+	// including `assets/images` as their prefix.
+	Filesystem fs.FS
+}
+
+func createFilesystem() filesystem {
+	return filesystem{
+		Filesystem: newDefaultFS(),
+	}
+}
+
+// Static registers a new route with path prefix to serve static files from the provided root directory.
+func (e *Echo) Static(pathPrefix, fsRoot string) *Route {
+	subFs := MustSubFS(e.Filesystem, fsRoot)
+	return e.Add(
+		http.MethodGet,
+		pathPrefix+"*",
+		StaticDirectoryHandler(subFs, false),
+	)
+}
+
+// StaticFS registers a new route with path prefix to serve static files from the provided file system.
+//
+// When dealing with `embed.FS` use `fs := echo.MustSubFS(fs, "rootDirectory") to create sub fs which uses necessary
+// prefix for directory path. This is necessary as `//go:embed assets/images` embeds files with paths
+// including `assets/images` as their prefix.
+func (e *Echo) StaticFS(pathPrefix string, filesystem fs.FS) *Route {
+	return e.Add(
+		http.MethodGet,
+		pathPrefix+"*",
+		StaticDirectoryHandler(filesystem, false),
+	)
+}
+
+// StaticDirectoryHandler creates handler function to serve files from provided file system
+// When disablePathUnescaping is set then file name from path is not unescaped and is served as is.
+func StaticDirectoryHandler(fileSystem fs.FS, disablePathUnescaping bool) HandlerFunc {
+	return func(c Context) error {
+		p := c.Param("*")
+		if !disablePathUnescaping { // when router is already unescaping we do not want to do is twice
+			tmpPath, err := url.PathUnescape(p)
+			if err != nil {
+				return fmt.Errorf("failed to unescape path variable: %w", err)
+			}
+			p = tmpPath
+		}
+
+		// fs.FS.Open() already assumes that file names are relative to FS root path and considers name with prefix `/` as invalid
+		name := filepath.ToSlash(filepath.Clean(strings.TrimPrefix(p, "/")))
+		fi, err := fs.Stat(fileSystem, name)
+		if err != nil {
+			return ErrNotFound
+		}
+
+		// If the request is for a directory and does not end with "/"
+		p = c.Request().URL.Path // path must not be empty.
+		if fi.IsDir() && len(p) > 0 && p[len(p)-1] != '/' {
+			// Redirect to ends with "/"
+			return c.Redirect(http.StatusMovedPermanently, p+"/")
+		}
+		return fsFile(c, name, fileSystem)
+	}
+}
+
+// FileFS registers a new route with path to serve file from the provided file system.
+func (e *Echo) FileFS(path, file string, filesystem fs.FS, m ...MiddlewareFunc) *Route {
+	return e.GET(path, StaticFileHandler(file, filesystem), m...)
+}
+
+// StaticFileHandler creates handler function to serve file from provided file system
+func StaticFileHandler(file string, filesystem fs.FS) HandlerFunc {
+	return func(c Context) error {
+		return fsFile(c, file, filesystem)
+	}
+}
+
+// defaultFS emulates os.Open behaviour with filesystem opened by `os.DirFs`. Difference between `os.Open` and `fs.Open`
+// is that FS does not allow to open path that start with `..` or `/` etc. For example previously you could have `../images`
+// in your application but `fs := os.DirFS("./")` would not allow you to use `fs.Open("../images")` and this would break
+// all old applications that rely on being able to traverse up from current executable run path.
+// NB: private because you really should use fs.FS implementation instances
+type defaultFS struct {
+	prefix string
+	fs     fs.FS
+}
+
+func newDefaultFS() *defaultFS {
+	dir, _ := os.Getwd()
+	return &defaultFS{
+		prefix: dir,
+		fs:     os.DirFS(dir),
+	}
+}
+
+func (fs defaultFS) Open(name string) (fs.File, error) {
+	return fs.fs.Open(name)
+}
+
+func subFS(currentFs fs.FS, root string) (fs.FS, error) {
+	root = filepath.ToSlash(filepath.Clean(root)) // note: fs.FS operates only with slashes. `ToSlash` is necessary for Windows
+	if dFS, ok := currentFs.(*defaultFS); ok {
+		// we need to make exception for `defaultFS` instances as it interprets root prefix differently from fs.FS to
+		// allow cases when root is given as `../somepath` which is not valid for fs.FS
+		root = filepath.Join(dFS.prefix, root)
+		return &defaultFS{
+			prefix: root,
+			fs:     os.DirFS(root),
+		}, nil
+	}
+	return fs.Sub(currentFs, root)
+}
+
+// MustSubFS creates sub FS from current filesystem or panic on failure.
+// Panic happens when `fsRoot` contains invalid path according to `fs.ValidPath` rules.
+//
+// MustSubFS is helpful when dealing with `embed.FS` because for example `//go:embed assets/images` embeds files with
+// paths including `assets/images` as their prefix. In that case use `fs := echo.MustSubFS(fs, "rootDirectory") to
+// create sub fs which uses necessary prefix for directory path.
+func MustSubFS(currentFs fs.FS, fsRoot string) fs.FS {
+	subFs, err := subFS(currentFs, fsRoot)
+	if err != nil {
+		panic(fmt.Errorf("can not create sub FS, invalid root given, err: %w", err))
+	}
+	return subFs
+}