allow template hot reload

package.json

@@ -10,7 +10,6 @@
         "build:watch": "node build/build.js --watch",
         "build:ui": "node packages/ui-default/build",
         "build:ui:dev": "node packages/ui-default/build --dev",
-        "build:ui:watch": "node packages/ui-default/build --watch",
         "build:ui:production": "node packages/ui-default/build --production",
         "lint": "eslint packages --ext ts --fix",
         "lint:ci": "eslint packages --ext ts",
@@ -19,7 +18,7 @@
         "snowpack": "cd packages/ui-default && snowpack dev",
         "pub": "node build/publish",
         "jest": "node build/jest",
-        "debug": "node --async-stack-traces --trace-deprecation --enable-source-maps build/start --debug",
+        "debug": "node --async-stack-traces --trace-deprecation --enable-source-maps build/start --debug --template",
         "start": "node build/start",
         "clean": "zsh -c \"rm -rf tsconfig.build.tsbuildinfo ./packages/*/tsconfig.tsbuildinfo ./packages/*/dist ./.coverage\""
     },

packages/ui-default/backendlib/template.js

@@ -88,9 +88,19 @@ class Loader extends nunjucks.Loader {
       };
     }
     let fullpath = null;
+    if (typeof argv.template !== 'string') argv.template = path.resolve(__dirname, '..', 'template');
     const p = path.resolve(process.cwd(), argv.template, name);
     if (fs.existsSync(p)) fullpath = p;
-    if (!fullpath) throw new Error(`Cannot get template ${name}`);
+    if (!fullpath) {
+      if (global.Hydro.ui.template[name]) {
+        return {
+          src: global.Hydro.ui.template[name],
+          path: name,
+          noCache: true,
+        };
+      }
+      throw new Error(`Cannot get template ${name}`);
+    }
     return {
       src: fs.readFileSync(fullpath, 'utf-8').toString(),
       path: fullpath,