feat: throw if attempting to respect DOM connect without a FASTElement

packages/web-components/fast-element/src/debug.ts

@@ -32,6 +32,7 @@ const debugMessages = {
     [1511 /* invalidKey */]: "Key/value cannot be null or undefined. Are you trying to inject/register something that doesn't exist with DI?",
     [1512 /* noDefaultResolver */]: "'${key}' not registered. Did you forget to add @singleton()?",
     [1513 /* cyclicDependency */]: "Cyclic dependency found '${name}'.",
+    [1514 /* connectUpdateRequiresController */]: "Injected properties that are updated on changes to DOM connectivity require the target object to be an instance of FASTElement.",
 };
 
 const allPlaceholders = /(\$\{\w+?})/g;

packages/web-components/fast-element/src/di/di.ts

@@ -778,6 +778,11 @@ export const DI = Object.freeze({
 
                     if (respectConnection) {
                         const notifier = (this as any).$fastController;
+
+                        if (!notifier) {
+                            throw FAST.error(Message.connectUpdateRequiresController);
+                        }
+
                         const handleChange = () => {
                             const newContainer = DI.findResponsibleContainer(this);
                             const newValue = newContainer.get(key) as any;

packages/web-components/fast-element/src/interfaces.ts

@@ -216,6 +216,7 @@ export const enum Message {
     invalidKey = 1511,
     noDefaultResolver = 1512,
     cyclicDependency = 1513,
+    connectUpdateRequiresController = 1514
 }
 
 /**