Implement Deno upgrade based on Go

After the upgrade command, I implemented my own upgrade command using Go language.

Get the latest version

Let’s take a look at Deno’s source code first:

use deno_runtime::deno_fetch::reqwest::Client;
const RELEASE_URL: &str = "https://github.com/denoland/deno/releases";
...
async fn get_latest_release_version(
  client: &Client,
) -> Result<String, AnyError> {
  println!("Looking up latest version");

  let res = client
    .get(&format!("{}/latest", RELEASE_URL))
    .send()
    .await?;
  let version = res.url().path_segments().unwrap().last().unwrap();

  Ok(version.replace("v", ""))
}

• Analyze the above code Did the following things: Since it is an asynchronous function, use the println function to prompt that it is looking for a new version. Use the GET method to request https://github.com/denoland/deno/releases/latest

• https: //github.com/denoland/deno/releases/latest will redirect to the latest release https://github.com/denoland/deno/releases/tag/v1.7.1, and we will take it out through a string operation v1.7.1

• Call the replace method of the string to replace v with "" to get the version number

Let us use Go to implement it:

The code looks similar, such as template string writing and string processing

package release

import (
 "net/http"
 "strings"
)

func getLatestVersion() string{
 releaseURL := fmt.Sprintf("https://github.com/%s/%s/releases/latest", user, repo)
 resp, _ := http.Get(releaseURL)
 defer resp.Body.Close() // 为了防止内存泄漏

 pathArr := strings.Split(resp.Request.URL.Path, "/")
 latest := strings.Replace(pathArr[len(pathArr)-1], "v", "", 1)
 return latest
}

Version detection

SemVer is indispensable for version processing. We use go-version to handle version-related work. With version comparison, we can implement a version checking function. The following code is a piece of code in my encapsulated go-release:

type UpdateInfo struct {
 IsUpdate      bool
 LatestVersion string
}

func CheckUpdate(user string, repo string, current string) (updateInfo *UpdateInfo, err error) {
 releaseURL := fmt.Sprintf("https://github.com/%s/%s/releases/latest", user, repo)
 resp, err := http.Get(releaseURL)
 if err != nil {
  return nil, err
 }
 defer resp.Body.Close()

 current = strings.Replace(current, "v", "", 1)
 pathArr := strings.Split(resp.Request.URL.Path, "/")
 latest := strings.Replace(pathArr[len(pathArr)-1], "v", "", 1)

 currentVersion, err := version.NewVersion(current)
 if err != nil {
  return nil, err
 }
 latestVersion, err := version.NewVersion(latest)
 if err != nil {
  return nil, err
 }
 updateInfo = &UpdateInfo{
  IsUpdate:      currentVersion.LessThan(latestVersion),
  LatestVersion: latest,
 }
 return updateInfo, nil
}

cobra implements upgrade

In the following code, we are based on go -release implements a simple CLI with the upgrade command. The core logic is to compare whether the local version is the latest, and if not, install the latest one.

const Version = "0.0.1"

func checkUpgrade(current string) {
  fmt.Println("Looking up latest version")
 update, err := release.CheckUpdate("youngjuning", "tpc", current)
 if err != nil {
  panic(err)
 }
 if update.IsUpdate {
  fmt.Printf("Found latest version %v \n", update.LatestVersion)
  sh.Command("bash", "-c", "curl -fsSL https://raw.githubusercontent.com/youngjuning/tpc/main/install.sh | sh").Run()
 } else {
  fmt.Printf("Local version %v is the most recent release \n", current)
 }
}

var rootCmd = &cobra.Command{
 Use:     "app",
 Version: Version,
}

var cmdUpgrade = &cobra.Command{
 Use: "upgrade",
 Run: func(cmd *cobra.Command, args []string) {
  checkUpgrade(Version, force)
 },
}

func main() {
 rootCmd.AddCommand(cmdUpgrade)
 rootCmd.Execute()
}

强制更新方案

Node.js 命令行工具检查更新的正确姿势 对这个问题做了很深入的研究并实现了 Node 版的工具。核心逻辑就是每次执行命令时异步去执行检查更新。这句话翻译成 Go 就是用协程去执行检查更新的动作，这样执行命令还是会立马得到反馈，程序则会在后台执行检查更新，当检测到有新版本则强制更新。

完整代码在go-release/example，对 Cobra 不熟悉的同学可以看一下 Cobra 中文文档。

执行 shell 命令推荐 go-sh，它对 exec 包做了封装，提供了更好地使用体验（ PS：还不是因为我菜）

// rootCmd 代表没有调用子命令时的基础命令
var rootCmd = &cobra.Command{
 Use:     "tpc",
 Version: Version,
 Run: func(cmd *cobra.Command, args []string) {
  sh.Command("tpc", "-h").Run()
  },
  // 每次执行完命令后去执行检查更新，Start 表示不阻塞原来的任务，还有一个 Run 方法则是会阻塞
 PersistentPostRun: func(cmd *cobra.Command, args []string) {
  sh.Command("bash", "-c", "tpc upgrade --force=false").Start()
 },
}

go-release 的诞生

go-release 核心代码翻译自 Deno 的 upgrade，开源项目，点赞是我维护的动力，在此求个 Star。