fix: use empty stdin by default (#590)

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## master (unreleased)
 
+- fix: use empty stdin by default ([#590](https://github.com/evilmartians/lefthook/pull/590)) by @mrexox
 - feat: add priorities to commands ([#589](https://github.com/evilmartians/lefthook/pull/589)) by @mrexox
 
 ## 1.5.4 (2023-11-27)

internal/lefthook/run/exec/execute_unix.go

@@ -29,7 +29,10 @@ type executeArgs struct {
 }
 
 func (e CommandExecutor) Execute(ctx context.Context, opts Options, out io.Writer) error {
-	in := os.Stdin
+	var in io.Reader = nullReader{}
+	if opts.UseStdin {
+		in = os.Stdin
+	}
 	if opts.Interactive && !isatty.IsTerminal(os.Stdin.Fd()) {
 		tty, err := os.Open("/dev/tty")
 		if err == nil {

internal/lefthook/run/exec/execute_windows.go

@@ -29,8 +29,13 @@ func (e CommandExecutor) Execute(ctx context.Context, opts Options, out io.Write
 		)
 	}
 
+	var in io.Reader = nullReader{}
+	if opts.Interactive || opts.UseStdin {
+		in = os.Stdin
+	}
+
 	args := &executeArgs{
-		in:   os.Stdin,
+		in:   in,
 		out:  out,
 		envs: envs,
 		root: root,

internal/lefthook/run/exec/nullReader.go

@@ -0,0 +1,10 @@
+package exec
+
+import "io"
+
+// nullReader always returns EOF.
+type nullReader struct{}
+
+func (nullReader) Read(b []byte) (int, error) {
+	return 0, io.EOF
+}