first commit

packages/@n8n/ai-utilities/src/guards.ts

@@ -0,0 +1,35 @@
+import type { BaseChatMemory } from '@langchain/classic/memory';
+import type { BaseChatMessageHistory } from '@langchain/core/chat_history';
+import type { BaseChatModel } from '@langchain/core/language_models/chat_models';
+import type { BaseLLM } from '@langchain/core/language_models/llms';
+import type { Tool } from '@langchain/core/tools';
+
+function hasMethods<T>(obj: unknown, ...methodNames: Array<string | symbol>): obj is T {
+	return methodNames.every(
+		(methodName) =>
+			typeof obj === 'object' &&
+			obj !== null &&
+			methodName in obj &&
+			typeof (obj as Record<string | symbol, unknown>)[methodName] === 'function',
+	);
+}
+
+export function isBaseChatMemory(obj: unknown) {
+	return hasMethods<BaseChatMemory>(obj, 'loadMemoryVariables', 'saveContext');
+}
+
+export function isBaseChatMessageHistory(obj: unknown) {
+	return hasMethods<BaseChatMessageHistory>(obj, 'getMessages', 'addMessage');
+}
+
+export function isChatInstance(model: unknown): model is BaseChatModel {
+	const namespace = (model as BaseLLM)?.lc_namespace ?? [];
+
+	return namespace.includes('chat_models');
+}
+
+export function isToolsInstance(model: unknown): model is Tool {
+	const namespace = (model as Tool)?.lc_namespace ?? [];
+
+	return namespace.includes('tools');
+}