main.go

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"log"
	"net/http"
	"os/exec"
	"strings"

	"github.com/PuerkitoBio/goquery"
)

var (
	colorReset  = "\033[0m"
	colorRed    = "\033[31m"
	colorGreen  = "\033[32m"
	colorYellow = "\033[33m"
	colorBlue   = "\033[34m"
	colorPurple = "\033[35m"
	colorCyan   = "\033[36m"
	colorWhite  = "\033[37m"
)

const verURL = "https://github.com/neovim/neovim/releases"

func main() {
	versionOnMyMac, err := getInstalledNvimVersion()
	if err != nil {
		log.Fatal(err)
	}

	latestNightBuild, err := getLatestNightBuild()
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println("on my mac:          ", versionOnMyMac)
	fmt.Println("latest night build: ", latestNightBuild)

	if versionOnMyMac == latestNightBuild {
		fmt.Println(colorGreen + "OK " + colorReset + " you are up to date")
	} else {
		fmt.Println(colorYellow +
			"Yes! " +
			colorBlue +
			"on net is newer version" +
			colorReset,
		)
		fmt.Println("please visit: ", verURL)
	}
}

func getLatestNightBuild() (version string, err error) {
	res, err := http.Get(verURL)
	if err != nil {
		log.Fatal(err)
	}
	defer res.Body.Close()

	doc, err := goquery.NewDocumentFromReader(res.Body)
	if err != nil {
		log.Fatal(err)
	}

	versions := []string{}

	doc.
		Find(".release-header .f1").
		Each(func(i int, s *goquery.Selection) {
			title := s.Find("a").Text()
			versions = append(versions, title)
		})

	return string(versions[0]), nil
}

func getInstalledNvimVersion() (version string, err error) {
	var stdout bytes.Buffer
	var stderr bytes.Buffer

	cmd := exec.Command("nvim", "--version")
	cmd.Stdout = &stdout
	cmd.Stderr = &stderr
	err = cmd.Run()
	if err != nil {
		return "", err
	}

	lines, err := StringToLines(stdout.String())
	if err != nil {
		return "", err
	}

	return lines[0], nil
}

func StringToLines(s string) (lines []string, err error) {
	scanner := bufio.NewScanner(strings.NewReader(s))
	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}
	err = scanner.Err()
	return lines, err
}