Merge branch 'underfisk-underfisk/cqrs-docs'

src/decorators/command-handler.decorator.ts

@@ -2,6 +2,16 @@ import 'reflect-metadata';
 import { ICommand } from '../index';
 import { COMMAND_HANDLER_METADATA } from './constants';
 
+/**
+ * Decorator that marks a class as a Nest command handler. A command handler
+ * handles commands (actions) executed by your application code.
+ *
+ * The decorated class must implement the `ICommandHandler` interface.
+ *
+ * @param command command *type* to be handled by this handler.
+ *
+ * @see https://docs.nestjs.com/recipes/cqrs#commands
+ */
 export const CommandHandler = (command: ICommand): ClassDecorator => {
   return (target: object) => {
     Reflect.defineMetadata(COMMAND_HANDLER_METADATA, command, target);

src/decorators/events-handler.decorator.ts

@@ -2,6 +2,16 @@ import 'reflect-metadata';
 import { IEvent } from '../index';
 import { EVENTS_HANDLER_METADATA } from './constants';
 
+/**
+ * Decorator that marks a class as a Nest event handler. An event handler
+ * handles events executed by your application code.
+ *
+ * The decorated class must implement the `IEventHandler` interface.
+ *
+ * @param events one or more event *types* to be handled by this handler.
+ *
+ * @see https://docs.nestjs.com/recipes/cqrs#events
+ */
 export const EventsHandler = (...events: IEvent[]): ClassDecorator => {
   return (target: object) => {
     Reflect.defineMetadata(EVENTS_HANDLER_METADATA, events, target);

src/decorators/query-handler.decorator.ts

@@ -2,6 +2,16 @@ import 'reflect-metadata';
 import { IQuery } from '../interfaces';
 import { QUERY_HANDLER_METADATA } from './constants';
 
+/**
+ * Decorator that marks a class as a Nest query handler. A query handler
+ * handles queries executed by your application code.
+ *
+ * The decorated class must implement the `IQueryHandler` interface.
+ *
+ * @param query query *type* to be handled by this handler.
+ *
+ * @see https://docs.nestjs.com/recipes/cqrs#queries
+ */
 export const QueryHandler = (query: IQuery): ClassDecorator => {
   return (target: object) => {
     Reflect.defineMetadata(QUERY_HANDLER_METADATA, query, target);

src/decorators/saga.decorator.ts

@@ -1,6 +1,11 @@
 import 'reflect-metadata';
 import { SAGA_METADATA } from './constants';
 
+/**
+ * Decorator that marks a class as a Nest saga. Sagas may listen and react to 1..N events.
+ *
+ * @see https://docs.nestjs.com/recipes/cqrs#sagas
+ */
 export const Saga = (): PropertyDecorator => {
   return (target: object, propertyKey: string | symbol) => {
     const properties =