refactor: message and command entities (#229)

services/api/src/app/messages/command.service.ts

@@ -1,18 +1,18 @@
-import { Command } from '@entities/command';
 import { User } from '@entities/users/user';
 import { Injectable } from '@nestjs/common';
 import { HelpCommandUseCase } from '@usecases/commands/help';
 import { RenameRoomUseCase } from '@usecases/rooms/rename';
 import { RenameUserUseCase } from '@usecases/users/rename';
 import { Dispatcher } from '@entities/messages/message';
 import { LoremCommandUseCase } from '@usecases/commands/lorem';
-import { ParseCommandUseCase } from '@usecases/commands/parse';
+import { ParseCommandUseCase } from '@usecases/commands/parse/parse-command';
 import { ConfigureRoomUseCase } from '@usecases/rooms/configure-room';
 import { P, match } from 'ts-pattern';
 import { InviteUseCase } from '@usecases/memberships/invite';
 import { LeaveRoomUseCase } from '@usecases/memberships/leave';
 import { AboutRoomUseCase } from '@usecases/rooms/about-room';
 import { ApproveRequestUseCase } from '@usecases/memberships/approve-request';
+import { IncomingCommand } from '@entities/commands';
 
 @Injectable()
 export class CommandService {
@@ -30,9 +30,10 @@ export class CommandService {
     readonly dispatcher: Dispatcher,
   ) {}
 
-  async exec(command: Command, authenticatedUser: User): Promise<void> {
+  async exec(command: IncomingCommand, authenticatedUser: User): Promise<void> {
     const { roomId } = command;
-    const parsedCommand = await this.parse.exec(command);
+    const parsedCommand = this.parse.exec(command);
+
     return match(parsedCommand)
       .with({ tag: 'help' }, () =>
         this.help.exec({ roomId, authenticatedUser }),

services/api/src/app/messages/messages.module.ts

@@ -4,7 +4,7 @@ import { MessagesController } from './messages.controller';
 import { AuthModule } from '@app/auth/auth.module';
 import { SendMessageUseCase } from '@usecases/messages/send';
 import { GetMessagesUseCase } from '@usecases/messages/get-messages';
-import { ParseCommandUseCase } from '@usecases/commands/parse';
+import { ParseCommandUseCase } from '@usecases/commands/parse/parse-command';
 import { CommandService } from '@app/messages/command.service';
 import { RenameRoomUseCase } from '@usecases/rooms/rename';
 import { RenameUserUseCase } from '@usecases/users/rename';

services/api/src/app/messages/messages.service.spec.ts

@@ -6,9 +6,9 @@ import { User } from '@entities/users/user';
 import { mock, MockProxy } from 'jest-mock-extended';
 import { SendMessageUseCase } from '@usecases/messages/send';
 import { CommandService } from './command.service';
-import { Command } from '@entities/command';
 import { UnauthorizedException } from '@nestjs/common';
 import { systemUser } from '@entities/users/system-user';
+import { IncomingCommand } from '@entities/commands';
 
 describe('MessagesService', () => {
   let service: MessagesService;
@@ -60,10 +60,10 @@ describe('MessagesService', () => {
 
       await service.handleMessage(message, authenticatedUser);
 
-      const expectedCommand: Command = {
-        tokens: ['help'],
-        canonicalInput: '/help',
+      const expectedCommand: IncomingCommand = {
+        content: '/help',
         roomId,
+        authorId: authenticatedUser.id,
       };
       expect(command.exec).toHaveBeenCalledWith(
         expectedCommand,

services/api/src/app/messages/messages.service.ts

@@ -2,9 +2,10 @@ import { HttpException, Injectable } from '@nestjs/common';
 import { CreateMessageDto } from './dto/messages';
 import { SendMessageUseCase } from '@usecases/messages/send';
 import { CommandService } from '@app/messages/command.service';
-import { isCommand, parseMessage } from '@usecases/messages/parse-message';
 import { systemUser } from '@entities/users/system-user';
 import { User } from '@entities/users/user';
+import { IncomingMessage } from '@entities/messages/message';
+import { isCommand } from '@entities/commands';
 
 @Injectable()
 export class MessagesService {
@@ -17,10 +18,10 @@ export class MessagesService {
     incoming: CreateMessageDto,
     authenticatedUser: User,
   ): Promise<void> {
-    const message = parseMessage({
+    const message: IncomingMessage = {
       ...incoming,
       authorId: authenticatedUser.id,
-    });
+    };
 
     try {
       if (isCommand(message)) {
@@ -30,18 +31,22 @@ export class MessagesService {
       }
     } catch (e) {
       if (e instanceof HttpException) {
-        await this.send.exec(
-          {
-            content: e.message,
-            roomId: incoming.roomId,
-            recipientId: authenticatedUser.id,
-            authorId: 'system',
-          },
+        return await this.send.exec(
+          this.getErrorMessage(e, message),
           systemUser,
         );
-      } else {
-        throw e;
       }
+
+      throw e;
     }
   }
+
+  private getErrorMessage(e: HttpException, message: IncomingMessage) {
+    return {
+      content: e.message,
+      roomId: message.roomId,
+      recipientId: message.authorId,
+      authorId: 'system',
+    };
+  }
 }

services/api/src/domain/entities/commands.ts

@@ -0,0 +1,14 @@
+import { IncomingMessage } from '@entities/messages/message';
+
+/**
+ * An incoming message which is a command. Any message with content prefixed by a forward slash is
+ * considered a command, where or not it can be parsed. If it cannot be parsed, it is an invalid
+ * command.
+ */
+export type IncomingCommand = IncomingMessage & {
+  content: `/${string}`;
+};
+
+export const isCommand = (
+  message: IncomingMessage,
+): message is IncomingCommand => message.content.startsWith('/');

services/api/src/domain/entities/messages/message.ts

@@ -7,19 +7,9 @@ export enum UpdatedEntity {
 }
 
 /**
- * A message that has been sent by a user and is stored in the system.
+ * A message received by the system but not yet stored, executed or dispatched to clients.
  */
-export type SentMessage = {
-  /**
-   * Unique identifier for the message.
-   */
-  id: string;
-
-  /**
-   * The time the message was sent (in ms since the epoch).
-   */
-  time: number;
-
+export type IncomingMessage = {
   /**
    * The text content of the message.
    */
@@ -34,7 +24,12 @@ export type SentMessage = {
    * The room the message was sent to.
    */
   roomId: string;
+};
 
+/**
+ * Type for draft messages which have not yet been sent by the system.
+ */
+export type DraftMessage = IncomingMessage & {
   /**
    * The recipient of the message.
    * If undefined, this is a public message sent to the room.
@@ -50,6 +45,21 @@ export type SentMessage = {
   updatedEntities?: UpdatedEntity[];
 };
 
+/**
+ * A message that has been sent by a user and is stored in the system.
+ */
+export type SentMessage = DraftMessage & {
+  /**
+   * Unique identifier for the message.
+   */
+  id: string;
+
+  /**
+   * The time the message was sent (in ms since the epoch).
+   */
+  time: number;
+};
+
 /**
  * A refinement of the `Message` type to indicate it is private.
  */
@@ -66,11 +76,6 @@ export const isPrivate = (message: SentMessage): message is PrivateMessage => {
   return (message as PrivateMessage).recipientId !== undefined;
 };
 
-/**
- * Type for draft messages which have not yet been sent by the system.
- */
-export type DraftMessage = Omit<SentMessage, 'id' | 'time'>;
-
 /**
  * Abstract class for dispatching and subscribing to messages. All messages will be sent and
  * delivered to subscribers through a `Dispatcher`.

services/api/src/domain/usecases/commands/help.ts

@@ -1,7 +1,8 @@
 import { Dispatcher } from '@entities/messages/message';
 import { User } from '@entities/users/user';
 import { Injectable } from '@nestjs/common';
-import { parsers } from './parse/parsers';
+
+import { commands } from '@usecases/commands/parse/commands';
 
 export type HelpParams = {
   authenticatedUser: User;
@@ -24,9 +25,9 @@ export class HelpCommandUseCase {
 
   private generateContent() {
     const title = 'Type to chat, or enter one of the following commands:';
-    const commands = parsers.map(
-      (parser) => `* \`${parser.signature}\`: ${parser.summary}`,
+    const commandSummaries = commands.map(
+      (command) => `* \`${command.signature}\`: ${command.summary}`,
     );
-    return [title, ...commands].join('\n');
+    return [title, ...commandSummaries].join('\n');
   }
 }