fix: auto enable hmr mode when using browser-refresh client and @marko/compiler/register (#1855)

Author: DylanPiercey

.changeset/khaki-boats-count.md

@@ -0,0 +1,5 @@
+---
+"@marko/compiler": patch
+---
+
+Fix browser-refresh client support when using @marko/compiler/register

packages/compiler/src/register.js

@@ -1,7 +1,9 @@
 "use strict";
 
 const compiler = require(".");
+const shouldOptimize = require("./util/should-optimize").default;
 const requiredOptions = { modules: "cjs" };
+const isDev = !shouldOptimize();
 
 module.exports = register;
 register();
@@ -14,8 +16,9 @@ function register({ extensions = require.extensions, ...options } = {}) {
         Object.assign(
           {
             meta: true,
+            hot: process.env.BROWSER_REFRESH_URL !== undefined,
             // eslint-disable-next-line no-constant-condition
-            sourceMaps: "MARKO_DEBUG" ? "inline" : false
+            sourceMaps: isDev ? "inline" : false
           },
           options,
           requiredOptions