Initial Nest.js backend

backend/src/auth/auth.service.ts

@@ -0,0 +1,45 @@
+import { Injectable, UnauthorizedException } from '@nestjs/common';
+import { UserService } from '../user/user.service';
+import { JwtService } from '@nestjs/jwt';
+
+interface AccessTokenPayload {
+  sub: string;
+  name: string;
+  isAdmin: boolean;
+}
+
+@Injectable()
+export class AuthService {
+  constructor(
+    private userService: UserService,
+    private jwtService: JwtService,
+  ) {}
+
+  async signIn(
+    name: string,
+    password: string,
+  ): Promise<{
+    token: string;
+  }> {
+    const user = await this.userService.findOneByName(name);
+
+    if (!(user && user.password === password)) {
+      throw new UnauthorizedException();
+    }
+
+    const payload: AccessTokenPayload = {
+      sub: user.id,
+      name: user.name,
+      isAdmin: user.isAdmin,
+    };
+
+    return {
+      token: await this.jwtService.signAsync(payload),
+    };
+  }
+}
+export type AuthUser = {
+  id: string;
+  name: string;
+  isAdmin: boolean;
+};