Enable installing bd canary

cmd/install.go

@@ -2,7 +2,9 @@ package cmd
 
 import (
 	"fmt"
+	"os"
 	"path"
+	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -14,6 +16,7 @@ import (
 func init() {
 	installCmd.Flags().StringP("path", "p", "", "Path to a Discord installation")
 	installCmd.Flags().StringP("channel", "c", "stable", "Discord release channel (stable|ptb|canary)")
+	installCmd.Flags().Bool("dev", false, "Use the development build of BetterDiscord")
 	rootCmd.AddCommand(installCmd)
 }
 
@@ -23,6 +26,7 @@ var installCmd = &cobra.Command{
 	Short:   "Installs BetterDiscord to your Discord",
 	Long:    "Install BetterDiscord by specifying either --path to a Discord install or --channel to auto-detect (default: stable).",
 	RunE: func(cmd *cobra.Command, args []string) error {
+		// Handle path and channel flags, ensuring they are mutually exclusive
 		pathFlag, _ := cmd.Flags().GetString("path")
 		channelFlag, _ := cmd.Flags().GetString("channel")
 
@@ -33,6 +37,14 @@ var installCmd = &cobra.Command{
 			return fmt.Errorf("--path and --channel are mutually exclusive")
 		}
 
+		// Check if the --dev flag is set or if the BDCLI_DEV_BUILD environment variable is enabled
+		useDevBuild := false
+		devFlag, _ := cmd.Flags().GetBool("dev")
+		if devFlag || isDevBuildEnvEnabled() {
+			useDevBuild = true
+			output.Println("⚠️  Using development build of BetterDiscord")
+		}
+
 		var install *discord.DiscordInstall
 
 		if pathProvided {
@@ -49,7 +61,7 @@ var installCmd = &cobra.Command{
 			}
 		}
 
-		if err := install.InstallBD(models.InstallOptions{RestartDiscord: true}); err != nil {
+		if err := install.InstallBD(models.InstallOptions{RestartDiscord: true, UseDevBuild: useDevBuild}); err != nil {
 			return fmt.Errorf("installation failed: %w", err)
 		}
 
@@ -83,3 +95,8 @@ var installCmd = &cobra.Command{
 		return nil
 	},
 }
+
+func isDevBuildEnvEnabled() bool {
+	value := strings.TrimSpace(strings.ToLower(os.Getenv("BDCLI_DEV_BUILD")))
+	return value == "1" || value == "true" || value == "yes"
+}

cmd/update.go

@@ -16,6 +16,11 @@ func init() {
 	rootCmd.AddCommand(updateCmd)
 }
 
+// This currently only checks for updates to the BetterDiscord loader (betterdiscord.asar).
+// In the future, we may also want to check for updates to the CLI itself.
+// This also only checks for updates to the stable release as the check is cheap (tag name)
+// the canary version is a rolling release and is not versioned, so it is not as easily
+// possible to check for updates to it.
 var updateCmd = &cobra.Command{
 	Use:   "update",
 	Short: "Update BetterDiscord to the latest version",
@@ -62,7 +67,7 @@ var updateCmd = &cobra.Command{
 
 		// Download the latest version
 		output.Println("📥 Downloading update...")
-		if err := bdinstall.Download(); err != nil {
+		if err := bdinstall.Download(false); err != nil {
 			return fmt.Errorf("failed to download update: %w", err)
 		}
 

internal/betterdiscord/download.go

@@ -13,14 +13,27 @@ import (
 var (
 	websiteAsarURL         = "https://betterdiscord.app/Download/betterdiscord.asar"
 	githubLatestReleaseURL = "https://api.github.com/repos/BetterDiscord/BetterDiscord/releases/latest"
+	// githubCanaryReleaseURL is the rolling pre-release tagged "canary" (rebuilt
+	// on every merge to the development branch). It is GitHub-only — the website
+	// has no mirror — so the dev-build path fetches it by tag rather than via the
+	// "latest" endpoint, which excludes pre-releases by design.
+	githubCanaryReleaseURL = "https://api.github.com/repos/BetterDiscord/BetterDiscord/releases/tags/canary"
 )
 
-func (i *BDInstall) download() error {
+func (i *BDInstall) download(useDevBuild bool) error {
 	if i.hasDownloaded {
 		output.Printf("✅ Already downloaded to %s\n", i.asar)
 		return nil
 	}
 
+	// The development build lives only on GitHub, so skip the website leg and go
+	// straight to the canary release. A failure here must NOT fall back to the
+	// stable asar: a developer who asked for the dev build silently receiving
+	// stable is a confusing, near-undetectable footgun.
+	if useDevBuild {
+		return i.downloadFromGitHubRelease(githubCanaryReleaseURL, "GitHub (development build)")
+	}
+
 	resp, err := utils.DownloadFile(websiteAsarURL, i.asar)
 	if err == nil {
 		version := resp.Header.Get("x-bd-version")
@@ -38,10 +51,16 @@ func (i *BDInstall) download() error {
 		output.Println("🔁 Falling back to GitHub...")
 	}
 
-	// Get download URL from GitHub API
-	apiData, err := utils.DownloadJSON[models.GitHubRelease](githubLatestReleaseURL)
+	return i.downloadFromGitHubRelease(githubLatestReleaseURL, "GitHub")
+}
+
+// downloadFromGitHubRelease fetches the release metadata at apiURL, locates the
+// betterdiscord.asar asset, and downloads it into the BD folder. sourceLabel is
+// used only for logging (e.g. "GitHub" or "GitHub (development build)").
+func (i *BDInstall) downloadFromGitHubRelease(apiURL, sourceLabel string) error {
+	apiData, err := utils.DownloadJSON[models.GitHubRelease](apiURL)
 	if err != nil {
-		output.Println("❌ Failed to get asset url from GitHub")
+		output.Printf("❌ Failed to get asset url from %s\n", sourceLabel)
 		output.Printf("❌ %s\n", err.Error())
 		return err
 	}
@@ -55,8 +74,8 @@ func (i *BDInstall) download() error {
 	}
 
 	if index == -1 {
-		output.Println("❌ Failed to find the BetterDiscord asar on GitHub")
-		return fmt.Errorf("failed to find betterdiscord.asar asset in GitHub release")
+		output.Printf("❌ Failed to find the BetterDiscord asar on %s\n", sourceLabel)
+		return fmt.Errorf("failed to find betterdiscord.asar asset in %s release", sourceLabel)
 	}
 
 	var downloadUrl = apiData.Assets[index].URL
@@ -69,15 +88,18 @@ func (i *BDInstall) download() error {
 	// Download asar into the BD folder
 	_, err = utils.DownloadFile(downloadUrl, i.asar)
 	if err != nil {
-		output.Println("❌ Failed to download BetterDiscord from GitHub")
+		output.Printf("❌ Failed to download BetterDiscord from %s\n", sourceLabel)
 		output.Printf("❌ %s\n", err.Error())
 		return err
 	}
 
-	if version == "" {
-		output.Println("✅ Downloaded BetterDiscord from GitHub")
-	} else {
-		output.Printf("✅ Downloaded BetterDiscord version %s from GitHub\n", output.FormatVersion(version))
+	switch version {
+	case "":
+		output.Printf("✅ Downloaded BetterDiscord from %s\n", sourceLabel)
+	case "canary":
+		output.Printf("✅ Downloaded BetterDiscord development build from %s\n", sourceLabel)
+	default:
+		output.Printf("✅ Downloaded BetterDiscord version %s from %s\n", output.FormatVersion(version), sourceLabel)
 	}
 	i.hasDownloaded = true
 

internal/betterdiscord/download_test.go

@@ -22,6 +22,17 @@ func withURLs(t *testing.T, website, github string) {
 	})
 }
 
+// withCanaryURL temporarily overrides the canary (development build) endpoint for
+// a test and restores it on cleanup.
+func withCanaryURL(t *testing.T, canary string) {
+	t.Helper()
+	orig := githubCanaryReleaseURL
+	githubCanaryReleaseURL = canary
+	t.Cleanup(func() {
+		githubCanaryReleaseURL = orig
+	})
+}
+
 func newBDInstallWithDataDir(t *testing.T) *BDInstall {
 	t.Helper()
 	install := New(filepath.Join(t.TempDir(), "BetterDiscord"))
@@ -59,7 +70,7 @@ func TestDownload_FromWebsite(t *testing.T) {
 	withURLs(t, website.URL, github.URL)
 
 	install := newBDInstallWithDataDir(t)
-	if err := install.download(); err != nil {
+	if err := install.download(false); err != nil {
 		t.Fatalf("download() failed: %v", err)
 	}
 	if !install.HasDownloaded() {
@@ -89,7 +100,7 @@ func TestDownload_FallsBackToGitHub(t *testing.T) {
 	withURLs(t, website.URL, github.URL)
 
 	install := newBDInstallWithDataDir(t)
-	if err := install.download(); err != nil {
+	if err := install.download(false); err != nil {
 		t.Fatalf("download() failed: %v", err)
 	}
 	if !install.HasDownloaded() {
@@ -112,11 +123,81 @@ func TestDownload_GitHubMissingAsset(t *testing.T) {
 	withURLs(t, website.URL, github.URL)
 
 	install := newBDInstallWithDataDir(t)
-	if err := install.download(); err == nil {
+	if err := install.download(false); err == nil {
 		t.Fatal("expected an error when the betterdiscord.asar asset is missing")
 	}
 }
 
+func TestDownload_DevBuildUsesCanaryAndSkipsWebsite(t *testing.T) {
+	const body = "asar-from-canary"
+	asset := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprint(w, body)
+	}))
+	defer asset.Close()
+
+	// Neither the website nor the "latest" endpoint should be touched for a dev build.
+	website := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Error("website should not be called for the development build")
+		http.Error(w, "unexpected", http.StatusInternalServerError)
+	}))
+	defer website.Close()
+
+	github := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Error("the GitHub latest endpoint should not be called for the development build")
+		http.Error(w, "unexpected", http.StatusInternalServerError)
+	}))
+	defer github.Close()
+
+	canary := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintf(w, `{"tag_name":"canary","assets":[{"name":"betterdiscord.asar","url":%q}]}`, asset.URL)
+	}))
+	defer canary.Close()
+
+	withURLs(t, website.URL, github.URL)
+	withCanaryURL(t, canary.URL)
+
+	install := newBDInstallWithDataDir(t)
+	if err := install.download(true); err != nil {
+		t.Fatalf("download(true) failed: %v", err)
+	}
+	if !install.HasDownloaded() {
+		t.Error("expected HasDownloaded() to be true after canary download")
+	}
+	assertFileContents(t, install.Asar(), body)
+}
+
+func TestDownload_DevBuildHardFailsWithoutStableFallback(t *testing.T) {
+	// The canary release is unreachable. The dev build must fail rather than
+	// silently falling back to the website or the stable GitHub release.
+	website := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Error("website should not be called as a fallback for the development build")
+		http.Error(w, "unexpected", http.StatusInternalServerError)
+	}))
+	defer website.Close()
+
+	github := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		t.Error("the GitHub latest endpoint should not be called as a fallback for the development build")
+		http.Error(w, "unexpected", http.StatusInternalServerError)
+	}))
+	defer github.Close()
+
+	canary := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, "down", http.StatusInternalServerError)
+	}))
+	defer canary.Close()
+
+	withURLs(t, website.URL, github.URL)
+	withCanaryURL(t, canary.URL)
+
+	install := newBDInstallWithDataDir(t)
+	if err := install.download(true); err == nil {
+		t.Fatal("expected an error when the canary release is unreachable")
+	}
+	if install.HasDownloaded() {
+		t.Error("expected HasDownloaded() to remain false after a failed dev build download")
+	}
+}
+
 func TestDownload_SkipsWhenAlreadyDownloaded(t *testing.T) {
 	install := newBDInstallWithDataDir(t)
 	install.hasDownloaded = true
@@ -125,7 +206,7 @@ func TestDownload_SkipsWhenAlreadyDownloaded(t *testing.T) {
 	// never touched when the asar is already downloaded.
 	withURLs(t, "http://127.0.0.1:0", "http://127.0.0.1:0")
 
-	if err := install.download(); err != nil {
+	if err := install.download(false); err != nil {
 		t.Fatalf("download() should be a no-op when already downloaded: %v", err)
 	}
-}
+}

internal/betterdiscord/install.go

@@ -51,9 +51,10 @@ func (i *BDInstall) HasDownloaded() bool {
 	return i.hasDownloaded
 }
 
-// Download downloads the BetterDiscord asar file
-func (i *BDInstall) Download() error {
-	return i.download()
+// Download downloads the BetterDiscord asar file. When useDevBuild is true it
+// pulls the rolling "canary" pre-release from GitHub instead of the stable asar.
+func (i *BDInstall) Download(useDevBuild bool) error {
+	return i.download(useDevBuild)
 }
 
 // Prepare creates all necessary directories for BetterDiscord

internal/discord/injection.go

@@ -232,4 +232,4 @@ func (discord *DiscordInstall) IsInjected() bool {
 		return false
 	}
 	return utils.Exists(filepath.Join(resources, "app", "index.js")) && utils.Exists(filepath.Join(resources, "betterdiscord.app.asar"))
-}
+}

internal/discord/injection_test.go

@@ -389,4 +389,4 @@ func TestInject_RollbackOnMidOpFailure(t *testing.T) {
 	if utils.Exists(filepath.Join(resources, "betterdiscord.app.asar")) {
 		t.Error("preserved asar should be gone after rollback")
 	}
-}
+}

internal/discord/install.go

@@ -11,11 +11,11 @@ import (
 )
 
 type DiscordInstall struct {
-	ResourcesPath  string           `json:"resourcesPath"`
-	Channel   models.DiscordChannel `json:"channel"`
-	Version   string                `json:"version"`
-	IsFlatpak bool                  `json:"isFlatpak"`
-	IsSnap    bool                  `json:"isSnap"`
+	ResourcesPath string                `json:"resourcesPath"`
+	Channel       models.DiscordChannel `json:"channel"`
+	Version       string                `json:"version"`
+	IsFlatpak     bool                  `json:"isFlatpak"`
+	IsSnap        bool                  `json:"isSnap"`
 }
 
 // InstallBD installs BetterDiscord into this Discord installation
@@ -41,7 +41,7 @@ func (discord *DiscordInstall) InstallBD(options models.InstallOptions) error {
 
 	// Download and write betterdiscord.asar
 	output.Println("📥 Downloading BetterDiscord...")
-	if err := bd.Download(); err != nil {
+	if err := bd.Download(options.UseDevBuild); err != nil {
 		return err
 	}
 	output.Println("✅ BetterDiscord downloaded")

internal/discord/install_test.go

@@ -88,4 +88,4 @@ func TestGetBetterDiscordInstall_FlatpakRecomputesDataRoot(t *testing.T) {
 			t.Errorf("channel %v: Root() = %s, expected %s", tc.channel, bd.Root(), want)
 		}
 	}
-}
+}