FakeAI "controller" object must not be copied

src/api/providers/fake-ai.ts

@@ -4,21 +4,52 @@ import { ApiHandlerOptions, ModelInfo } from "../../shared/api"
 import { ApiStream } from "../transform/stream"
 
 interface FakeAI {
+	/**
+	 * The unique identifier for the FakeAI instance.
+	 * It is used to lookup the original FakeAI object in the fakeAiMap
+	 * when the fakeAI object is read from the VSCode global state.
+	 */
+	readonly id: string
+
+	/**
+	 * A function set by the FakeAIHandler on the FakeAI instance, that removes
+	 * the FakeAI instance from the fakeAIMap when the FakeAI instance is
+	 * no longer needed.
+	 */
+	removeFromCache?: () => void
+
 	createMessage(systemPrompt: string, messages: Anthropic.Messages.MessageParam[]): ApiStream
 	getModel(): { id: string; info: ModelInfo }
 	countTokens(content: Array<Anthropic.Messages.ContentBlockParam>): Promise<number>
 	completePrompt(prompt: string): Promise<string>
 }
 
+/**
+ * API providers configuration is stored in the VSCode global state.
+ * Therefore, when a new task is created, the FakeAI object in the configuration
+ * is a new object not related to the original one, but with the same ID.
+ *
+ * We use the ID to lookup the original FakeAI object in the mapping.
+ */
+let fakeAiMap: Map<string, FakeAI> = new Map()
+
 export class FakeAIHandler implements ApiHandler, SingleCompletionHandler {
 	private ai: FakeAI
 
 	constructor(options: ApiHandlerOptions) {
-		if (!options.fakeAi) {
+		const optionsFakeAi = options.fakeAi as FakeAI | undefined
+		if (!optionsFakeAi) {
 			throw new Error("Fake AI is not set")
 		}
 
-		this.ai = options.fakeAi as FakeAI
+		const id = optionsFakeAi.id
+		let cachedFakeAi = fakeAiMap.get(id)
+		if (cachedFakeAi === undefined) {
+			cachedFakeAi = optionsFakeAi
+			cachedFakeAi.removeFromCache = () => fakeAiMap.delete(id)
+			fakeAiMap.set(id, cachedFakeAi)
+		}
+		this.ai = cachedFakeAi
 	}
 
 	async *createMessage(systemPrompt: string, messages: Anthropic.Messages.MessageParam[]): ApiStream {