Declare as INodeProperties instead of casting

credentials/FriendGridApi.credentials.ts

@@ -1,21 +1,21 @@
 import {
 	ICredentialType,
-	NodePropertyTypes,
+	INodeProperties,
 } from 'n8n-workflow';
 
 export class FriendGridApi implements ICredentialType {
 	name = 'friendGridApi';
 	displayName = 'FriendGrid API';
 	documentationUrl = 'friendGrid';
-	properties = [
+	properties: INodeProperties[] = [
 		// The credentials to get from user and save encrypted.
 		// Properties can be defined exactly in the same way
 		// as node properties.
 		{
 			displayName: 'API Key',
 			name: 'apiKey',
-			type: 'string' as NodePropertyTypes,
+			type: 'string',
 			default: '',
 		},
 	];
-}
+}

nodes/FriendGrid/descriptions/ContactDescription.ts

@@ -2,7 +2,7 @@ import {
 	INodeProperties,
 } from 'n8n-workflow';
 
-export const contactOperations = [
+export const contactOperations: INodeProperties[] = [
 	{
 		displayName: 'Operation',
 		name: 'operation',
@@ -24,9 +24,9 @@ export const contactOperations = [
 		default: 'create',
 		description: 'The operation to perform',
 	},
-] as INodeProperties[];
+];
 
-export const contactFields = [
+export const contactFields: INodeProperties[] = [
 	/*-------------------------------------------------------------------------- */
 	/*                                contact:create                             */
 	/* ------------------------------------------------------------------------- */
@@ -79,4 +79,4 @@ export const contactFields = [
 			},
 		],
 	},
-] as INodeProperties[];
+];