Under my package's `gen` folder

main.go

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/goadesign/goa/dslengine"
	"github.com/goadesign/goa/goagen/codegen"
	"github.com/goadesign/goa/goagen/gen_app"
	_ "github.com/abourget/featurette/design"
)

func main() {
	// if possible, shrink that to a single call, too..
	failOnError(dslengine.Errors)
	failOnError(dslengine.Run())

	// Now take the results and call the generator with it
	// FIXME: reduce that to a single line
	roots := make([]interface{}, len(dslengine.Roots))
	for i, r := range dslengine.Roots {
		roots[i] = r
	}

	codegen.OutputDir = "../test"
	codegen.DesignPackagePath = "github.com/abourget/featurette/design"
	
	// shrink these 3 lines to a single line too..
	files, err := genapp.Generate(roots)
	failOnError(err)
	fmt.Println(strings.Join(files, "\n"))
	
	failOrPrint(genswagger.Generate(roots))
	failOrPrint(genmyown.Generate(roots))
}

// FIXME: move to `codegen` or something..
func failOnError(err error) {
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s", err)
		os.Exit(1)
	}
}