a script built in go that attempts to run tests then build engo demos to test if changes break the build

main.go

package main

import (
	"bytes"
	"flag"
	"fmt"
	"go/build"
	"io/ioutil"
	"os"
	"os/exec"
)

var (
	path                    string
	run, gopherjs, gomobile bool
)

type BuildCommand uint

const (
	GoBuildCommand BuildCommand = iota
	GopherjsBuildCommand
	GomobileBuildCommand
)

func init() {
	gopath := os.Getenv("GOPATH")
	if gopath == "" {
		gopath = build.Default.GOPATH
	}
	flag.BoolVar(&run, "run", true, "run tries to build and run the demos")
	flag.BoolVar(&gopherjs, "gopherjs", false, "gopherjs tries to build the demos via gopherjs")
	flag.BoolVar(&gomobile, "gomobile", false, "gomobile tries to build the demos via gomobile")
	flag.StringVar(&path, "path", gopath+"/src/engo.io/engo", "path is the path to your engo library folder")
}

func main() {
	flag.Parse()
	runTests("go")
	if run {
		fmt.Println("attempting to build demos")
		buildDemos(GoBuildCommand)
		fmt.Println("demos built successfully!")
	}
	if gopherjs {
		runTests("gopherjs")
		fmt.Println("attempting to build with gopherjs")
		buildDemos(GopherjsBuildCommand)
		fmt.Println("gopherjs built successfully!")
	}
	if gomobile {
		fmt.Println("attempting to build with gomobile")
		buildDemos(GomobileBuildCommand)
		fmt.Println("gomobile built successfully!")
	}
}

func runTests(tool string) {
	cmd := exec.Command(tool, "test", "-v", "./...")
	cmd.Dir = path
	printCmdOutput(cmd)
}

func printCmdOutput(cmd *exec.Cmd) {
	var out []byte
	var err error
	if out, err = cmd.Output(); err != nil {
		switch outerr := err.(type) {
		case *exec.ExitError:
			buf := bytes.NewBuffer(outerr.Stderr)
			fmt.Println(buf.String())
		}
		panic(err)
	}
	buf := bytes.NewBuffer(out)
	fmt.Println(buf.String())
}

func buildDemos(bc BuildCommand) {
	tmp, err := ioutil.TempDir(path+"/demos", "build")
	if err != nil {
		panic(err)
	}
	defer os.RemoveAll(tmp)
	fi, err := ioutil.ReadDir(path + "/demos")
	if err != nil {
		panic(err)
	}
	for _, file := range fi {
		if file.IsDir() {
			if file.Name() != "demoutils" && path+"/demos/"+file.Name() != tmp {
				fmt.Println("building " + file.Name())
				var cmd *exec.Cmd
				switch bc {
				case GoBuildCommand:
					cmd = exec.Command("go", "build", "-o="+tmp+"/"+file.Name(), "--tags=demo")
				case GopherjsBuildCommand:
					cmd = exec.Command("gopherjs", "build", "-o="+tmp+"/"+file.Name()+".js", "--tags=demo")
				case GomobileBuildCommand:
					cmd = exec.Command("gomobile", "build", "-o="+tmp+"/"+file.Name()+".apk", "--tags=demo")
				default:
					panic("build command not found")
				}
				cmd.Dir = path + "/demos/" + file.Name()
				printCmdOutput(cmd)
				fmt.Println("Sucessfully built " + file.Name())
			}
		}
	}
}