refactor: Overhaul nodes-testing setup - Part 1 (no-changelog) (#14303)

packages/nodes-base/test/nodes/load-nodes-and-credentials.ts

@@ -0,0 +1,39 @@
+import { Service } from '@n8n/di';
+import { LazyPackageDirectoryLoader } from 'n8n-core';
+import type {
+	ICredentialType,
+	INodeType,
+	IVersionedNodeType,
+	KnownNodesAndCredentials,
+	LoadedClass,
+} from 'n8n-workflow';
+
+@Service()
+export class LoadNodesAndCredentials {
+	private loader: LazyPackageDirectoryLoader;
+
+	readonly known: KnownNodesAndCredentials = { nodes: {}, credentials: {} };
+
+	constructor(baseDir: string) {
+		this.loader = new LazyPackageDirectoryLoader(baseDir);
+	}
+
+	async init() {
+		await this.loader.loadAll();
+		this.known.credentials = this.loader.known.credentials;
+		this.known.nodes = this.loader.known.nodes;
+	}
+
+	recognizesCredential(credentialType: string): boolean {
+		return credentialType in this.known.credentials;
+	}
+
+	getCredential(credentialType: string): LoadedClass<ICredentialType> {
+		return this.loader.getCredential(credentialType);
+	}
+
+	getNode(fullNodeType: string): LoadedClass<INodeType | IVersionedNodeType> {
+		const nodeType = fullNodeType.split('.')[1];
+		return this.loader.getNode(nodeType);
+	}
+}