$EDIX-4591: return unsubscribe method

src/API.ts

@@ -46,12 +46,16 @@ export interface EntryPointOrPackagesMap {
     [name: string]: EntryPointOrPackage
 }
 
+export interface Contribution {
+    unsubscribe(): void
+}
+
 export type ExtensionItemFilter<T> = (extensionItem: ExtensionItem<T>) => boolean
 export interface ExtensionSlot<T> {
     readonly name: string
     readonly host: AppHost
     readonly declaringShell?: Shell
-    contribute(shell: Shell, item: T, condition?: ContributionPredicate): void
+    contribute(shell: Shell, item: T, condition?: ContributionPredicate): Contribution
     getItems(forceAll?: boolean): ExtensionItem<T>[]
     getSingleItem(): ExtensionItem<T>
     getItemByName(name: string): ExtensionItem<T>

src/extensionSlot.ts

@@ -7,7 +7,8 @@ import {
     Shell,
     SlotKey,
     CustomExtensionSlot,
-    CustomExtensionSlotHandler
+    CustomExtensionSlotHandler,
+    Contribution
 } from './API'
 import _ from 'lodash'
 
@@ -32,13 +33,21 @@ export function createExtensionSlot<T>(key: SlotKey<T>, host: AppHost, declaring
         discardBy
     }
 
-    function contribute(fromShell: Shell, item: T, condition?: ContributionPredicate): void {
-        items.push({
+    function contribute(fromShell: Shell, item: T, condition?: ContributionPredicate): Contribution {
+        const contribution = {
             shell: fromShell,
             contribution: item,
             condition: condition || alwaysTrue,
             uniqueId: _.uniqueId(`${fromShell.name}_extItem_`)
-        })
+        }
+
+        items.push(contribution)
+
+        return {
+            unsubscribe: () => {
+                items = items.filter(i => i !== contribution)
+            }
+        }
     }
 
     function getItems(forceAll: boolean = false): ExtensionItem<T>[] {

src/index.ts

@@ -17,7 +17,8 @@ export {
     ShellLoggerSpan,
     HostLogger,
     LogSeverity,
-    APILayer
+    APILayer,
+    Contribution
 } from './API'
 
 export { AppMainView } from './appMainView'