package cli

import (
	"bytes"
	"os"
	"testing"
)

func TestRunNoArgs(t *testing.T) {
	oldStdout := os.Stdout
	r, w, _ := os.Pipe()
	os.Stdout = w

	err := Run([]string{})

	w.Close()
	os.Stdout = oldStdout

	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestRunHelp(t *testing.T) {
	oldStdout := os.Stdout
	r, w, _ := os.Pipe()
	os.Stdout = w

	err := Run([]string{"help"})

	w.Close()
	os.Stdout = oldStdout

	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestRunUnknownCommand(t *testing.T) {
	err := Run([]string{"unknown"})
	if err == nil {
		t.Fatal("expected error for unknown command")
	}
}

func TestRunOutput(t *testing.T) {
	oldStdout := os.Stdout
	r, w, _ := os.Pipe()
	os.Stdout = w

	Run([]string{})

	w.Close()
	os.Stdout = oldStdout

	buf := new(bytes.Buffer)
	buf.ReadFrom(r)
	if buf.Len() == 0 {
		t.Fatal("expected output")
	}
}