initial working version

internal/browser/browser.go

@@ -0,0 +1,27 @@
+package browser
+
+import (
+	"fmt"
+	"os/exec"
+	"runtime"
+)
+
+// Open opens the given URL in the user's default browser.
+func Open(url string) error {
+	var cmd *exec.Cmd
+
+	switch runtime.GOOS {
+	case "linux":
+		cmd = exec.Command("xdg-open", url)
+	case "darwin":
+		cmd = exec.Command("open", url)
+	default:
+		return fmt.Errorf("unsupported platform %s; open this URL manually:\n  %s", runtime.GOOS, url)
+	}
+
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("failed to open browser: %w\n  Open this URL manually:\n  %s", err, url)
+	}
+
+	return nil
+}