--- /dev/null
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fake
+
+import (
+ "fmt"
+
+ "golang.org/x/tools/internal/proxydir"
+)
+
+// WriteProxy creates a new proxy file tree using the txtar-encoded content,
+// and returns its URL.
+func WriteProxy(tmpdir, txt string) (string, error) {
+ files := unpackTxt(txt)
+ type moduleVersion struct {
+ modulePath, version string
+ }
+ // Transform into the format expected by the proxydir package.
+ filesByModule := make(map[moduleVersion]map[string][]byte)
+ for name, data := range files {
+ modulePath, version, suffix := splitModuleVersionPath(name)
+ mv := moduleVersion{modulePath, version}
+ if _, ok := filesByModule[mv]; !ok {
+ filesByModule[mv] = make(map[string][]byte)
+ }
+ filesByModule[mv][suffix] = data
+ }
+ for mv, files := range filesByModule {
+ if err := proxydir.WriteModuleVersion(tmpdir, mv.modulePath, mv.version, files); err != nil {
+ return "", fmt.Errorf("error writing %s@%s: %v", mv.modulePath, mv.version, err)
+ }
+ }
+ return proxydir.ToURL(tmpdir), nil
+}