better typings

Author: icebob

template/mixins/db.mixin.ts

@@ -1,14 +1,12 @@
-import type { Context, Service, ServiceSchema } from "moleculer";
+import type { Context, ServiceSettingSchema, ServiceSchema } from "moleculer";
 import type { DatabaseMethods } from "../moleculer-types.js";
 import { Service as DbService } from "@moleculer/database";
 
-export type DbServiceMethods = {
+export type DbServiceMethods = DatabaseMethods & {
 	seedDB?(): Promise<void>;
 };
 
-type DbServiceSchema = Partial<ServiceSchema>;
-
-export type DbServiceThis = Service & DbServiceMethods & DatabaseMethods;
+type DbServiceSchema = Partial<ServiceSchema<ServiceSettingSchema, DbServiceMethods>>;
 
 export default function (collection: string): DbServiceSchema {
 	const cacheCleanEventName = `cache.clean.${collection}`;

template/package.json

@@ -26,6 +26,7 @@
     "@types/node": "^22.15.29",
     {{#lint}}
 		"@eslint/js": "^9.28.0",
+    "@vitest/coverage-v8": "^3.2.4",
     "eslint": "^9.28.0",
     "eslint-config-prettier": "^10.1.5",
     "eslint-plugin-prettier": "^5.4.1",

template/services/greeter.service.ts

@@ -1,4 +1,4 @@
-import type { Context, Service, ServiceSchema, ServiceSettingSchema } from "moleculer";
+import type { Context, ServiceSchema, ServiceSettingSchema } from "moleculer";
 
 export interface ActionHelloParams {
 	name: string;
@@ -16,9 +16,7 @@ interface GreeterLocalVars {
 	myVar: string;
 }
 
-type GreeterThis = Service<GreeterSettings> & GreeterMethods & GreeterLocalVars;
-
-const GreeterService: ServiceSchema<GreeterSettings> = {
+const GreeterService: ServiceSchema<GreeterSettings, GreeterMethods, GreeterLocalVars> = {
 	name: "greeter",
 
 	/**
@@ -50,7 +48,7 @@ const GreeterService: ServiceSchema<GreeterSettings> = {
 			{{#apiGQL}}graphql: {
 				query: "hello: String"
 			},{{/apiGQL}}
-			async handler(this: GreeterThis /* , ctx: Context */): Promise<string> {
+			async handler(/* , ctx: Context */): Promise<string> {
 				return "Hello Moleculer";
 			}
 		},
@@ -68,8 +66,8 @@ const GreeterService: ServiceSchema<GreeterSettings> = {
 			{{#apiGQL}}graphql: {
 				mutation: "welcome(name: String!): String"
 			},{{/apiGQL}}
-			async handler(this: GreeterThis, ctx: Context<ActionHelloParams>): Promise<string> {
-				return `Welcome, ${ctx.params.name}`;
+			async handler(ctx: Context<ActionHelloParams>): Promise<string> {
+				return `Welcome, ${this.uppercase(ctx.params.name)}`;
 			}
 		}
 	},
@@ -82,26 +80,27 @@ const GreeterService: ServiceSchema<GreeterSettings> = {
 	/**
 	 * Methods. More info: https://moleculer.services/docs/0.15/services.html#Methods
 	 */
-	methods: {},
+	methods: {
+		uppercase(str: string): string {
+			return str.toUpperCase();
+		}
+	},
 
 	/**
 	 * Service created lifecycle event handler
 	 * More info: https://moleculer.services/docs/0.15/lifecycle.html#created-event-handler
-	 * @this {import('moleculer').Service}
 	 */
 	created() {},
 
 	/**
 	 * Service started lifecycle event handler
 	 * More info: https://moleculer.services/docs/0.15/lifecycle.html#started-event-handler
-	 * @this {import('moleculer').Service}
 	 */
 	async started() {},
 
 	/**
 	 * Service stopped lifecycle event handler
 	 * More info: https://moleculer.services/docs/0.15/lifecycle.html#stopped-event-handler
-	 * @this {import('moleculer').Service}
 	 */
 	async stopped() {}
 };

template/services/inventory.service.ts

@@ -1,5 +1,10 @@
 import type { Context, Service, ServiceSchema, ServiceSettingSchema } from "moleculer";
 
+interface ReserveParams {
+	productId: string;
+	quantity: number;
+}
+
 const InventoryService: ServiceSchema = {
 	name: "inventory",
 
@@ -9,12 +14,10 @@ const InventoryService: ServiceSchema = {
 	channels: {
 		/**
 		 * Reserve a product in the inventory.
-		 *
-		 * @this {import('moleculer').Service}
 		 */
 		"inventory.reserve": {
 			context: true,
-			async handler(this: Service, ctx: Context<{ productId: string; quantity: number }>) {
+			async handler(ctx: Context<ReserveParams>) {
 				// Simulate external API call to reserve the quantity...
 				await new Promise(resolve => setTimeout(resolve, 1000));
 
@@ -46,7 +49,7 @@ const InventoryService: ServiceSchema = {
 				productId: { type: "string" },
 				quantity: { type: "number" }
 			},
-			async handler(ctx: Context<{ productId: string; quantity: number }>) {
+			async handler(ctx: Context<ReserveParams>) {
 				await this.broker.sendToChannel(
 					"inventory.reserve",
 					{

template/services/products.service.ts

@@ -1,6 +1,7 @@
-import type { Context, Service, ServiceSchema } from "moleculer";
-import type { DatabaseMethods, DatabaseSettings, ApolloServiceSettings } from "../moleculer-types.js";
+import type { Context, ServiceSchema } from "moleculer";
+import type { DatabaseSettings, ApolloServiceSettings } from "../moleculer-types.js";
 import DbMixin from "../mixins/db.mixin.js";
+import type { DbServiceMethods } from "../mixins/db.mixin.js";
 
 export interface ProductEntity {
 	id: string;
@@ -18,16 +19,14 @@ export interface ActionQuantityParams {
 
 interface ProductSettings extends DatabaseSettings, ApolloServiceSettings {}
 
-interface ProductsThis extends Service<ProductSettings>, DatabaseMethods {};
-
-const ProductsService: ServiceSchema<ProductSettings> = {
+const ProductsService: ServiceSchema<ProductSettings, DbServiceMethods> = {
 	name: "products",
 	// version: 1
 
 	/**
 	 * Mixins. More info: https://moleculer.services/docs/0.15/services.html#Mixins
 	 */
-	mixins: [DbMixin("products")],
+	mixins: [DbMixin("products") as ServiceSchema],
 
 	/**
 	 * Settings. More info: https://moleculer.services/docs/0.15/services.html#Settings
@@ -161,7 +160,7 @@ const ProductsService: ServiceSchema<ProductSettings> = {
 			{{#apiGQL}}graphql: {
 				mutation: "increaseQuantity(id: String!, value: Int!): Product"
 			},{{/apiGQL}}
-			async handler(this: ProductsThis, ctx: Context<ActionQuantityParams>): Promise<ProductEntity> {
+			async handler(ctx: Context<ActionQuantityParams>): Promise<ProductEntity> {
 				// Get current quantity
 				const adapter = await this.getAdapter(ctx);
 				const dbEntry = await adapter.findById<ProductEntity>(ctx.params.id);
@@ -191,7 +190,7 @@ const ProductsService: ServiceSchema<ProductSettings> = {
 			{{#apiGQL}}graphql: {
 				mutation: "decreaseQuantity(id: String!, value: Int!): Product"
 			},{{/apiGQL}}
-			async handler(this: ProductsThis, ctx: Context<ActionQuantityParams>): Promise<ProductEntity> {
+			async handler(ctx: Context<ActionQuantityParams>): Promise<ProductEntity> {
 				// Get current quantity
 				const adapter = await this.getAdapter(ctx);
 				const dbEntry = await adapter.findById<ProductEntity>(ctx.params.id);
@@ -207,12 +206,13 @@ const ProductsService: ServiceSchema<ProductSettings> = {
 					quantity: newQuantity
 				});
 
+				{{#needChannels}}
 				if (doc.quantity === 0) {
 					this.logger.info(`Stock of ${doc.name} depleted... Ordering more`);
 					// Emit a persistent event to order more products
 					// inventory.service will handle this event
 					this.broker.sendToChannel("order.more", doc);
-				}
+				}{{/needChannels}}
 
 				return doc;
 			}
@@ -228,7 +228,7 @@ const ProductsService: ServiceSchema<ProductSettings> = {
 		 * It is called in the DB.mixin after the database
 		 * connection establishing & the collection is empty.
 		 */
-		async seedDB(this: ProductsThis) {
+		async seedDB() {
 			const adapter = await this.getAdapter();
 			await adapter.insertMany([
 				{ name: "Samsung Galaxy S10 Plus", quantity: 10, price: 704 },

template/test/unit/services/products.spec.ts

@@ -104,7 +104,7 @@ describe("Test 'products' service", () => {
 						value: -5
 					});
 				} catch (err) {
-					expect(err).toBeInstanceOf(ValidationError);
+					expect(err).toBeInstanceOf(Errors.ValidationError);
 					expect(err.data).toEqual([
 						{
 							action: "products.decreaseQuantity",