⚡ Make it possible to set credentials to fixed values

packages/cli/src/CredentialsOverwrites.ts

@@ -0,0 +1,56 @@
+import {
+	ICredentialDataDecryptedObject,
+} from 'n8n-workflow';
+
+import {
+	ICredentialsOverwrite,
+	GenericHelpers,
+} from './';
+
+
+class CredentialsOverwritesClass {
+
+	private overwriteData: ICredentialsOverwrite = {};
+
+	async init() {
+		const data = await GenericHelpers.getConfigValue('credentials.overwrite') as string;
+
+		try {
+			this.overwriteData = JSON.parse(data);
+		} catch (error) {
+			throw new Error(`The credentials-overwrite is not valid JSON.`);
+		}
+	}
+
+	applyOverwrite(type: string, data: ICredentialDataDecryptedObject) {
+		const overwrites = this.get(type);
+
+		if (overwrites === undefined) {
+			return data;
+		}
+
+		const returnData = JSON.parse(JSON.stringify(data));
+		Object.assign(returnData, overwrites);
+
+		return returnData;
+	}
+
+	get(type: string): ICredentialDataDecryptedObject | undefined {
+		return this.overwriteData[type];
+	}
+
+	getAll(): ICredentialsOverwrite {
+		return this.overwriteData;
+	}
+}
+
+
+let credentialsOverwritesInstance: CredentialsOverwritesClass | undefined;
+
+export function CredentialsOverwrites(): CredentialsOverwritesClass {
+	if (credentialsOverwritesInstance === undefined) {
+		credentialsOverwritesInstance = new CredentialsOverwritesClass();
+	}
+
+	return credentialsOverwritesInstance;
+}