Evaluate all env vars as part of async flow start

packages/node_modules/@node-red/runtime/lib/flows/Group.js

@@ -0,0 +1,55 @@
+const flowUtil = require("./util");
+const credentials = require("../nodes/credentials");
+
+/**
+ * This class represents a group within the runtime.
+ */
+class Group {
+
+    /**
+     * Create a Group object.
+     * @param {[type]} parent     The parent flow/group
+     * @param {[type]} groupDef   This group's definition
+     */
+    constructor(parent, groupDef) {
+        this.TYPE = 'group'
+        this.name = groupDef.name
+        this.parent = parent
+        this.group = groupDef
+        this.id = this.group.id
+        this.g = this.group.g
+        this.env = this.group.env
+        this._env = {}
+    }
+
+    async start() {
+        if (this.env) {
+            this._env = await flowUtil.evaluateEnvProperties(this, this.env, credentials.get(this.id))
+        }
+    }
+    /**
+     * Get a group setting value.
+     * @param  {[type]} key [description]
+     * @return {[type]}     [description]
+     */
+    getSetting(key) {
+        if (key === "NR_GROUP_NAME") {
+            return this.name;
+        }
+        if (key === "NR_GROUP_ID") {
+            return this.id;
+        }
+        if (!key.startsWith("$parent.")) {
+            if (this._env.hasOwnProperty(key)) {
+                return this._env[key]
+            }
+        } else {
+            key = key.substring(8);
+        }
+        return this.parent.getSetting(key);
+    }
+}
+
+module.exports = {
+    Group
+}