Start api directory, which will become a module.

api/filesys/fileinmemory.go

@@ -0,0 +1,56 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package filesys
+
+import (
+	"bytes"
+	"os"
+)
+
+var _ File = &fileInMemory{}
+
+// fileInMemory implements File in-memory for tests.
+type fileInMemory struct {
+	name    string
+	content []byte
+	dir     bool
+	open    bool
+}
+
+// makeDir makes a fake directory.
+func makeDir(name string) *fileInMemory {
+	return &fileInMemory{name: name, dir: true}
+}
+
+// Close marks the fake file closed.
+func (f *fileInMemory) Close() error {
+	f.open = false
+	return nil
+}
+
+// Read never fails, and doesn't mutate p.
+func (f *fileInMemory) Read(p []byte) (n int, err error) {
+	return len(p), nil
+}
+
+// Write saves the contents of the argument to memory.
+func (f *fileInMemory) Write(p []byte) (n int, err error) {
+	f.content = p
+	return len(p), nil
+}
+
+// ContentMatches returns true if v matches fake file's content.
+func (f *fileInMemory) ContentMatches(v []byte) bool {
+	return bytes.Equal(v, f.content)
+}
+
+// GetContent the content of a fake file.
+func (f *fileInMemory) GetContent() []byte {
+	return f.content
+}
+
+// Stat returns nil.
+func (f *fileInMemory) Stat() (os.FileInfo, error) {
+	return nil, nil
+}