Add mechanism for NPM package auto-discovery

src/support/PackageDiscovered.ts

@@ -0,0 +1,33 @@
+import {Event} from '../event/Event'
+import {Awaitable, JSONState, UniversalPath} from '../util'
+import {ExtolloAwareNodeModule} from './types'
+
+/**
+ * An event indicating that an NPM package has been discovered
+ * by the framework.
+ *
+ * Application services can listen for this event to register
+ * various discovery logic (e.g. automatically boot units
+ */
+export class PackageDiscovered extends Event {
+    constructor(
+        public packageConfig: ExtolloAwareNodeModule,
+        public packageJson: UniversalPath,
+    ) {
+        super()
+    }
+
+    dehydrate(): Awaitable<JSONState> {
+        return {
+            packageConfig: this.packageConfig as JSONState,
+            packageJson: this.packageJson.toString(),
+        }
+    }
+
+    rehydrate(state: JSONState): Awaitable<void> {
+        if ( typeof state === 'object' ) {
+            this.packageConfig = (state.packageConfig as ExtolloAwareNodeModule)
+            this.packageJson = new UniversalPath(String(state.packageJson))
+        }
+    }
+}