elvish-clone/pkg/mods/file/file_unix_test.go

//go:build !windows && !plan9 && !js

package file

import (
	"os"
	"testing"

	"src.elv.sh/pkg/eval"
	"src.elv.sh/pkg/eval/evaltest"
)

func TestIsTTY(t *testing.T) {
	setup := func(ev *eval.Evaler) {
		ev.ExtendGlobal(eval.BuildNs().AddNs("file", Ns))
	}

	if canOpen("/dev/null") {
		evaltest.TestWithSetup(t, setup,
			That("file:is-tty 0 < /dev/null").Puts(false),
			That("file:is-tty (num 0) < /dev/null").Puts(false),
		)
	}
	if canOpen("/dev/tty") {
		evaltest.TestWithSetup(t, setup,
			That("file:is-tty 0 < /dev/tty").Puts(true),
			That("file:is-tty (num 0) < /dev/tty").Puts(true),
		)
	}
}

func canOpen(name string) bool {
	f, err := os.Open(name)
	f.Close()
	return err == nil
}