npmlink.go

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"os/user"
	"path/filepath"
	"strings"
)

func buildDist(dir string) string {
	log.Println("Building dist...")
	cmd := exec.Command("npm", "run", "dist")
	cmd.Dir = dir
	out, err := cmd.Output()
	handleErr(err, "Error building dist"+dir)
	return string(out)
}

func copyNpmrc(dir string) string {
	log.Println("Copying .npmrc into dist...")
	cmd := exec.Command("cp", ".npmrc", "dist")
	cmd.Dir = dir
	out, err := cmd.Output()
	handleErr(err, "Error copying .npmrc into dist"+dir)
	return string(out)
}

func updateNpmrc(dir string) string {
	log.Println("Updating location of cafile...")
	npmrc := fmt.Sprintf("%s/dist/.npmrc", dir)
	input, err := ioutil.ReadFile(npmrc)
	handleErr(err, "Error reading .npmrc")

	lines := strings.Split(string(input), "\n")
	for i, l := range lines {
		if strings.HasPrefix(l, "cafile") {
			lines[i] = "cafile=../../cafile.pem"
			break
		}
	}

	output := strings.Join(lines, "\n")
	err = ioutil.WriteFile(npmrc, []byte(output), 0644)
	handleErr(err, "Error writing to .npmrc"+dir)

	return "Updated .npmrc"
}

func makeLink(dir string) string {
	log.Printf("Creating npm link to %s...\n", dir)
	cmd := exec.Command("npm", "link")
	cmd.Dir = dir
	out, err := cmd.Output()
	handleErr(err, "Error making link for project at "+dir)
	return string(out)
}

func link(dir string, project string) string {
	log.Printf("Linking %s to %s...\n", dir, project)
	cmd := exec.Command("npm", "link", "@oreilly/"+project)
	cmd.Dir = dir
	out, err := cmd.Output()
	handleErr(err, "Error linking project at "+dir)
	return string(out)
}

func handleErr(err error, s string) {
	if err != nil {
		log.Println(s)
		log.Fatal(err)
	}
}

func main() {
	var basePath string

	if len(os.Args) == 4 {
		p, err := filepath.Abs(os.Args[3])
		handleErr(err, "Error resolving path")
		basePath = p
	} else {
		u, err := user.Current()
		handleErr(err, "Error obtaining user")
		h := u.HomeDir
		basePath = fmt.Sprintf("%s/src/frontend", h)
	}

	projectLink := fmt.Sprintf("%s/%s", basePath, os.Args[1])
	projectDest := fmt.Sprintf("%s/%s", basePath, os.Args[2])

	buildDist(projectLink)
	copyNpmrc(projectLink)
	updateNpmrc(projectLink)
	makeLink(projectLink + "/dist")
	link(projectDest, os.Args[1])

	log.Println("Did the thing.")
}