Added notice for when a new version is available to upgrade to

README.md

@@ -44,7 +44,39 @@ To install via Winget, run:
 winget install Twitch.TwitchCLI
 ```
 
-To update, run:
+### Manual Download
+
+To download, go to the [Releases tab of GitHub](https://github.com/twitchdev/twitch-cli/releases). The examples in the documentation assume you have put this into your PATH and renamed to `twitch` (or symlinked as such).
+
+**Note**: If using MacOS and downloading manually, you may need to adjust the permissions of the file to allow for execution.
+
+To do so, please run: `chmod 755 <filename>` where the filename is the name of the downloaded binary. 
+
+## Updating
+
+To update the Twitch CLI, run the command relevant to your installation method.
+
+**NOTE:** Once a day the program will make an HTTP call to Github to check if the application is of the latest version. For information on disabling this, see *Disabling release version checks and notices* below.
+
+### Homebrew
+
+To update using Homebrew, run:
+
+```sh
+brew upgrade twitchdev/twitch/twitch-cli
+```
+
+### Scoop
+
+To update using Scoop, run:
+
+```sh
+scoop update twitch-cli
+```
+
+### WinGet
+
+To update using WinGet, run:
 
 ```sh
 winget update Twitch.TwitchCLI
@@ -56,7 +88,26 @@ To download, go to the [Releases tab of GitHub](https://github.com/twitchdev/twi
 
 **Note**: If using MacOS and downloading manually, you may need to adjust the permissions of the file to allow for execution.
 
-To do so, please run: `chmod 755 <filename>` where the filename is the name of the downloaded binary. 
+To do so, please run: `chmod 755 <filename>` where the filename is the name of the downloaded binary.
+
+## Disabling release version checks and notices
+
+When the Twitch CLI exits successfully, the application will automatically check the Twitch CLI's Github releases at the following URL:
+
+```
+https://api.github.com/repos/twitchdev/twitch-cli/releases/latest
+```
+
+If the version of the Twitch CLI you are running is older than the latest released version, a notice will be printed to the console.
+
+To prevent this from happening, make one of the following changes:
+
+- Set the environment variable `CI` to `true`
+- Set the environment variable `TWITCH_DISABLE_UPDATE_CHECKS` to `true`
+- Add `DISABLE_UPDATE_CHECKS=true` to your **.twitch-cli.env** configuration file
+- SET `LAST_UPDATE_CHECK` to `3000-01-01` in your **.twitch-cli.env** configuration file, which will prevent it from running until the year 3000
+
+If you're running the Twitch CLI in a CI/CD environment, most environments will have already set the `CI` environment variable to `true`.
 
 ## Usage
 

cmd/root.go

@@ -23,10 +23,14 @@ var rootCmd = &cobra.Command{
 // Execute adds all child commands to the root command and sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.
 func Execute() {
+	// Execute normally; Exit without checking for updates if there's an error.
 	if err := rootCmd.Execute(); err != nil {
 		fmt.Println(err)
 		os.Exit(1)
 	}
+
+	// Check Github's Releases API to see if we're running the latest version.
+	util.CheckForUpdatesAndPrintNotice()
 }
 
 func init() {

go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/fsnotify/fsnotify v1.4.9 // indirect
+	github.com/hashicorp/go-version v1.6.0 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/hokaccha/go-prettyjson v0.0.0-20201222001619-a42f9ac2ec8e // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect

go.sum

@@ -98,6 +98,8 @@ github.com/hashicorp/go-sockaddr v1.0.0/go.mod h1:7Xibr9yA9JjQq1JpNB2Vw7kxv8xerX
 github.com/hashicorp/go-syslog v1.0.0/go.mod h1:qPfqrKkXGihmCqbJM2mZgkZGvKG1dFdvsLplgctolz4=
 github.com/hashicorp/go-uuid v1.0.0/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
 github.com/hashicorp/go-uuid v1.0.1/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
+github.com/hashicorp/go-version v1.6.0 h1:feTTfFNnjP967rlCxM/I9g701jU+RN74YKx2mOkIeek=
+github.com/hashicorp/go-version v1.6.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
 github.com/hashicorp/go.net v0.0.1/go.mod h1:hjKkEWcCURg++eb33jQU7oqQcI9XDCnUzHA0oac0k90=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
@@ -149,7 +151,6 @@ github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNx
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.18 h1:DOKFKCQ7FNG2L1rbrmstDN4QVRdS89Nkh85u68Uwp98=
 github.com/mattn/go-isatty v0.0.18/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
-github.com/mattn/go-sqlite3 v1.14.6 h1:dNPt6NO46WmLVt2DLNpwczCmdV5boIZ6g/tlDrlRUbg=
 github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/mattn/go-sqlite3 v1.14.17 h1:mCRHCLDUBXgpKAqIKsaAaAsrAlbkeomtRFKXh2L6YIM=
 github.com/mattn/go-sqlite3 v1.14.17/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=

internal/util/version_checker.go

@@ -0,0 +1,132 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+package util
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/fatih/color"
+	"github.com/spf13/viper"
+
+	vrs "github.com/hashicorp/go-version"
+)
+
+type updateCheckerReleasesResponse struct {
+	// Only thing we really care about here is the tag name
+	TagName string `json:"tag_name"`
+}
+
+// Check Github's Releases API to see if we're running the latest version.
+// If there's any errors, quietly allow it to fail.
+func CheckForUpdatesAndPrintNotice() {
+	// Don't bother running this if current application is built from source
+	if strings.EqualFold(GetVersion(), "source") {
+		return
+	}
+
+	// Don't run if program is running in CI/CD (CI env variable will be set), or if TWITCH_DISABLE_UPDATE_CHECKS is set to true.
+	if viper.GetBool("disable_update_checks") || strings.EqualFold(os.Getenv("CI"), "true") {
+		return
+	}
+
+	// Don't run if this already ran successfully today
+	today, _ := time.Parse(time.DateOnly, time.Now().Format(time.DateOnly))
+	lastRunDate, _ := time.Parse(time.DateOnly, viper.GetString("last_update_check"))
+	if !today.After(lastRunDate) {
+		return
+	}
+
+	runningLatestVersion, latestVersionTag, err := areWeRunningLatestVersion()
+	if err != nil {
+		return // Drop errors without notifying
+	}
+
+	if !runningLatestVersion {
+		// Messages to be displayed
+		messages := []string{
+			" A new Twitch CLI release is available: " + latestVersionTag + " ",
+			"",
+			" See upgrade instructions at: ",
+			" https://github.com/twitchdev/twitch-cli/blob/main/README.md#updating ",
+			"",
+			" Check out the release notes at: ",
+			" https://github.com/twitchdev/twitch-cli/releases/latest ",
+		}
+
+		// Find longest message
+		longestMessageLength := 0
+		for _, str := range messages {
+			if len(str) > longestMessageLength {
+				longestMessageLength = len(str)
+			}
+		}
+
+		// Print messages
+		shaded := color.New(color.BgWhite, color.FgBlack).SprintfFunc()
+
+		fmt.Println()
+		for _, str := range messages {
+			fmt.Printf(" %v\n", shaded(str+strings.Repeat(" ", longestMessageLength-len(str))))
+		}
+		fmt.Println()
+
+		// Update config so this isn't repeated until tomorrow
+		viper.Set("last_update_check", GetTimestamp().Format(time.DateOnly))
+		configPath, err := GetConfigPath()
+		if err != nil {
+			return
+		}
+		_ = viper.WriteConfigAs(configPath)
+	}
+}
+
+// Makes the call to Github's Releases API to check for the latest release version, and compares it to the current version.
+func areWeRunningLatestVersion() (bool, string, error) {
+	REGEX_TAG_NAME_VERSION := regexp.MustCompile("^(?:v)(.+)") // Removes the v from the start of the tag, if it exists
+
+	client := &http.Client{
+		Timeout: time.Second * 2,
+	}
+
+	req, err := http.NewRequest("GET", "https://api.github.com/repos/twitchdev/twitch-cli/releases/latest", nil)
+	if err != nil {
+		return false, "", err
+	}
+	req.Header.Set("User-Agent", "twitch-cli/"+GetVersion())
+
+	response, err := client.Do(req)
+	if err != nil {
+		return false, "", err
+	}
+	defer response.Body.Close()
+
+	body, err := io.ReadAll(response.Body)
+	if err != nil {
+		return false, "", err
+	}
+
+	var obj updateCheckerReleasesResponse
+	err = json.Unmarshal(body, &obj)
+	if err != nil {
+		return false, "", err
+	}
+
+	latestReleaseVersion, err := vrs.NewVersion(REGEX_TAG_NAME_VERSION.FindAllStringSubmatch(obj.TagName, -1)[0][1])
+	if err != nil {
+		return false, "", err
+	}
+
+	currentVersion, err := vrs.NewVersion(GetVersion())
+	if err != nil {
+		return false, "", err
+	}
+
+	return currentVersion.GreaterThanOrEqual(latestReleaseVersion), obj.TagName, nil
+}