Add a -f flag to overwrite, and update tests

2 files changed, 120 insertions, 9 deletions

diff --git a/dec/dec.go b/dec/dec.go
index ce0a719..049bc74 100644
--- a/dec/dec.go
+++ b/dec/dec.go
@@ -3,22 +3,34 @@ package main
 import (
 	"flag"
 	"fmt"
+	"io"
 	"os"
 
 	"golang.org/x/term"
 	"roseh.moe/cmd/sym/internal/sym"
 )
 
-var passwordFlag = flag.String("p", "", "use the specified password; if not provided, dec will prompt for a password")
+type options struct {
+	password string
+	force    bool
 
-func dec() error {
-	args := flag.Args()
-	if len(args) == 0 && *passwordFlag == "" {
+	stdin  io.Reader
+	stdout io.Writer
+}
+
+func (o *options) dec(args ...string) error {
+	if o.stdin == nil {
+		o.stdin = os.Stdin
+	}
+	if o.stdout == nil {
+		o.stdout = os.Stdout
+	}
+	if len(args) == 0 && o.password == "" {
 		return fmt.Errorf("-p is required when reading from stdin")
 	}
 	var password string
-	if *passwordFlag != "" {
-		password = *passwordFlag
+	if o.password != "" {
+		password = o.password
 	} else {
 		fmt.Fprint(os.Stderr, "Enter password: ")
 		pw, err := term.ReadPassword(int(os.Stdin.Fd()))
@@ -29,10 +41,10 @@ func dec() error {
 		password = string(pw)
 	}
 	if len(args) == 0 {
-		return sym.Decrypt(os.Stdout, os.Stdin, password)
+		return sym.Decrypt(o.stdout, o.stdin, password)
 	}
 	for _, fileName := range args {
-		if err := sym.DecryptFile(fileName, password); err != nil {
+		if err := sym.DecryptFile(fileName, password, sym.Force(o.force)); err != nil {
 			return err
 		}
 	}
@@ -40,8 +52,11 @@ func dec() error {
 }
 
 func main() {
+	o := new(options)
+	flag.StringVar(&o.password, "p", "", "use the specified password; if not provided, dec will prompt for a password")
+	flag.BoolVar(&o.force, "f", false, "overwrite output files even if they already exist")
 	flag.Parse()
-	if err := dec(); err != nil {
+	if err := o.dec(flag.Args()...); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
diff --git a/dec/dec_test.go b/dec/dec_test.go
new file mode 100644
index 0000000..823ab68
--- /dev/null
+++ b/dec/dec_test.go
@@ -0,0 +1,96 @@
+package main
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"roseh.moe/cmd/sym/internal/sym"
+)
+
+func mustWriteFile(t *testing.T, path string, content []byte) {
+	t.Helper()
+	if err := os.WriteFile(path, content, 0600); err != nil {
+		t.Fatalf("Failed to write test file: %s", err)
+	}
+}
+
+func mustReadFile(t *testing.T, path string) []byte {
+	t.Helper()
+	content, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("Failed to read file: %s", err)
+	}
+	return content
+}
+
+func mustRemove(t *testing.T, path string) {
+	t.Helper()
+	if err := os.Remove(path); err != nil {
+		t.Fatalf("Failed to remove file: %s", err)
+	}
+}
+
+func TestDec(t *testing.T) {
+	t.Parallel()
+
+	const password = "asdf"
+	fileContent := []byte("test file content")
+	fileName := filepath.Join(t.TempDir(), "file")
+	mustWriteFile(t, fileName, fileContent)
+	if err := sym.EncryptFile(fileName, password); err != nil {
+		t.Errorf("EncryptFile failed: %s", err)
+	}
+	mustRemove(t, fileName)
+	err := (&options{password: password}).dec(fileName + ".enc")
+	if err != nil {
+		t.Errorf("dec failed: %s", err)
+	}
+	gotFileContents := mustReadFile(t, fileName)
+	if !bytes.Equal(gotFileContents, fileContent) {
+		t.Errorf("dec returned incorrect contents %q, want %q", gotFileContents, fileContent)
+	}
+}
+
+func TestDec_UsageError(t *testing.T) {
+	t.Parallel()
+
+	err := (&options{}).dec()
+	if err == nil {
+		t.Errorf("dec without -p when reading from stdin, want error")
+	}
+}
+
+func TestDec_NotFound(t *testing.T) {
+	t.Parallel()
+
+	err := (&options{password: "asdf"}).dec("my-nonexistent-file-name.txt")
+	if err == nil {
+		t.Errorf("dec succeeded with nonexistent file, want error")
+	}
+}
+
+func TestDec_Stdin(t *testing.T) {
+	t.Parallel()
+
+	const password = "asdf"
+	content := []byte("test contents")
+	encrypted := new(bytes.Buffer)
+	if err := sym.EncryptBinary(encrypted, bytes.NewReader(content), password); err != nil {
+		t.Fatalf("Failed to encrypt: %s", err)
+	}
+	gotContentBuf := new(bytes.Buffer)
+	opts := &options{
+		password: password,
+		stdin:    bytes.NewReader(encrypted.Bytes()),
+		stdout:   gotContentBuf,
+	}
+	if err := opts.dec(); err != nil {
+		t.Fatalf("dec failed: %s", err)
+	}
+	gotContent := gotContentBuf.Bytes()
+	if !bytes.Equal(gotContent, content) {
+		t.Errorf("dec returned incorrect contents %q, want %q", gotContent, content)
+	}
+}