1 files changed, 127 insertions, 0 deletions
diff --git a/src/os/read_test.go b/src/os/read_test.go
new file mode 100644
index 0000000..5c58d7d
--- /dev/null
+++ b/src/os/read_test.go
@@ -0,0 +1,127 @@
+// Copyright 2009 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 os_test
+
+import (
+	"bytes"
+	. "os"
+	"path/filepath"
+	"testing"
+)
+
+func checkNamedSize(t *testing.T, path string, size int64) {
+	dir, err := Stat(path)
+	if err != nil {
+		t.Fatalf("Stat %q (looking for size %d): %s", path, size, err)
+	}
+	if dir.Size() != size {
+		t.Errorf("Stat %q: size %d want %d", path, dir.Size(), size)
+	}
+}
+
+func TestReadFile(t *testing.T) {
+	filename := "rumpelstilzchen"
+	contents, err := ReadFile(filename)
+	if err == nil {
+		t.Fatalf("ReadFile %s: error expected, none found", filename)
+	}
+
+	filename = "read_test.go"
+	contents, err = ReadFile(filename)
+	if err != nil {
+		t.Fatalf("ReadFile %s: %v", filename, err)
+	}
+
+	checkNamedSize(t, filename, int64(len(contents)))
+}
+
+func TestWriteFile(t *testing.T) {
+	f, err := CreateTemp("", "ioutil-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	defer Remove(f.Name())
+
+	msg := "Programming today is a race between software engineers striving to " +
+		"build bigger and better idiot-proof programs, and the Universe trying " +
+		"to produce bigger and better idiots. So far, the Universe is winning."
+
+	if err := WriteFile(f.Name(), []byte(msg), 0644); err != nil {
+		t.Fatalf("WriteFile %s: %v", f.Name(), err)
+	}
+
+	data, err := ReadFile(f.Name())
+	if err != nil {
+		t.Fatalf("ReadFile %s: %v", f.Name(), err)
+	}
+
+	if string(data) != msg {
+		t.Fatalf("ReadFile: wrong data:\nhave %q\nwant %q", string(data), msg)
+	}
+}
+
+func TestReadOnlyWriteFile(t *testing.T) {
+	if Getuid() == 0 {
+		t.Skipf("Root can write to read-only files anyway, so skip the read-only test.")
+	}
+
+	// We don't want to use CreateTemp directly, since that opens a file for us as 0600.
+	tempDir, err := MkdirTemp("", t.Name())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer RemoveAll(tempDir)
+	filename := filepath.Join(tempDir, "blurp.txt")
+
+	shmorp := []byte("shmorp")
+	florp := []byte("florp")
+	err = WriteFile(filename, shmorp, 0444)
+	if err != nil {
+		t.Fatalf("WriteFile %s: %v", filename, err)
+	}
+	err = WriteFile(filename, florp, 0444)
+	if err == nil {
+		t.Fatalf("Expected an error when writing to read-only file %s", filename)
+	}
+	got, err := ReadFile(filename)
+	if err != nil {
+		t.Fatalf("ReadFile %s: %v", filename, err)
+	}
+	if !bytes.Equal(got, shmorp) {
+		t.Fatalf("want %s, got %s", shmorp, got)
+	}
+}
+
+func TestReadDir(t *testing.T) {
+	dirname := "rumpelstilzchen"
+	_, err := ReadDir(dirname)
+	if err == nil {
+		t.Fatalf("ReadDir %s: error expected, none found", dirname)
+	}
+
+	dirname = "."
+	list, err := ReadDir(dirname)
+	if err != nil {
+		t.Fatalf("ReadDir %s: %v", dirname, err)
+	}
+
+	foundFile := false
+	foundSubDir := false
+	for _, dir := range list {
+		switch {
+		case !dir.IsDir() && dir.Name() == "read_test.go":
+			foundFile = true
+		case dir.IsDir() && dir.Name() == "exec":
+			foundSubDir = true
+		}
+	}
+	if !foundFile {
+		t.Fatalf("ReadDir %s: read_test.go file not found", dirname)
+	}
+	if !foundSubDir {
+		t.Fatalf("ReadDir %s: exec directory not found", dirname)
+	}
+}