main.go

package main

import (
	"fmt"
)

func main() {
	fmt.Println("hello")
}

main_test.go

package main

import (
	"testing"
)

func TestMain(t *testing.T) {
	main()
}

run_test.go

// Copyright (C) 2013 Ato ARAKI. All rights reserved
package main_test

import (
	"io"
	"log"
	"os"
	"os/exec"
	"testing"
)

// Test for invoke process.
func TestRun(t *testing.T) {
	err := doCompile(".")
	if err != nil {
		log.Fatal(err)
	}

	cmd := exec.Command("./main")

	stdout, err := cmd.StdoutPipe()
	if err != nil {
		log.Fatal(err)
	}
	stderr, err := cmd.StderrPipe()
	if err != nil {
		log.Fatal(err)
	}
	if err := cmd.Start(); err != nil {
		log.Fatal(err)
	}
	go io.Copy(os.Stdout, stdout)
	go io.Copy(os.Stdout, stderr)

	if err := cmd.Wait(); err != nil {
		t.Fatal(err)
	}
}

func doCompile(target string) error {
	cmd := exec.Command("go", "build", target)

	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return err
	}
	stderr, err := cmd.StderrPipe()
	if err != nil {
		return err
	}
	if err := cmd.Start(); err != nil {
		return err
	}
	go io.Copy(os.Stdout, stdout)
	go io.Copy(os.Stdout, stderr)

	if err := cmd.Wait(); err != nil {
		return err
	}
	return nil
}