feat(Feat/cache): Create custom cache decorator (#31)

* Chore: pretty

* Feat: Implement cache decorator for providers (service)

- Install related dependencies
- Add custom cache dynamic module

* Feat: Implement cache interceptor for resolver

- Divide set cache logic

* Chore: Update dependencies

* Docs: Update README.md

Author: Ho-s

README.md

@@ -119,6 +119,28 @@ You can use like below.
 $ yarn g
 ```
 
+## Caching
+
+This project provides a custom decorator that makes it easy to implement method caching in NestJS applications.
+
+1. **Caching Functionality**: Utilizes `DiscoveryService` and `MetadataScanner` to handle method caching automatically at runtime.
+2. **Usage**: Designed for use with any provider.
+3. **GraphQL Resolvers**: Resolvers are also part of providers, but due to GraphQL's internal logic, method overrides do not work. Therefore, the functionality has been replaced with an interceptor.
+
+You can use like below
+
+```js
+@Injectable()
+export class ExampleService {
+  @Cache(...)
+  async exampleMethod(arg: string) {
+    ...
+  }
+}
+```
+
+You can find related codes [here](./src/cache/custom-cache.module.ts)
+
 ## Getting Started
 
 ### Installation
@@ -339,7 +361,7 @@ db.public.registerFunction({
 - [x] Refresh Token
 - [ ] Redis
 - [ ] ElasticSearch
-- [ ] Caching
+- [x] Caching
 - [ ] Graphql Subscription
 - [ ] Remove lodash
 - [ ] [CASL](https://docs.nestjs.com/security/authorization#integrating-casl)

package.json

@@ -30,11 +30,12 @@
   },
   "dependencies": {
     "@apollo/server": "^4.10.5",
-    "@aws-sdk/client-s3": "^3.620.1",
-    "@aws-sdk/lib-storage": "^3.620.1",
+    "@aws-sdk/client-s3": "^3.621.0",
+    "@aws-sdk/lib-storage": "^3.621.0",
     "@aws-sdk/types": "^3.609.0",
     "@nestjs/apollo": "^12.2.0",
     "@nestjs/axios": "^3.0.2",
+    "@nestjs/cache-manager": "^2.2.2",
     "@nestjs/common": "^10.3.10",
     "@nestjs/config": "^3.2.3",
     "@nestjs/core": "^10.3.10",
@@ -48,6 +49,7 @@
     "apollo-server-express": "^3.13.0",
     "axios": "^1.7.2",
     "bcrypt": "^5.1.1",
+    "cache-manager": "^5.7.4",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.14.1",
     "graphql": "^16.9.0",
@@ -72,28 +74,28 @@
     "@nestjs/schematics": "^10.1.3",
     "@nestjs/testing": "^10.3.10",
     "@swc/cli": "^0.4.0",
-    "@swc/core": "^1.7.3",
+    "@swc/core": "^1.7.4",
     "@swc/jest": "^0.2.36",
     "@trivago/prettier-plugin-sort-imports": "^4.3.0",
     "@types/bcrypt": "^5.0.2",
     "@types/express": "^4.17.21",
     "@types/graphql-upload": "^15.0.2",
     "@types/jest": "29.5.12",
     "@types/lodash": "^4.17.7",
-    "@types/node": "^22.0.0",
+    "@types/node": "^22.0.2",
     "@types/passport-jwt": "^4.0.1",
     "@types/passport-local": "^1.0.38",
     "@types/supertest": "^6.0.2",
     "@types/uuid": "^10.0.0",
-    "@typescript-eslint/eslint-plugin": "^7.18.0",
-    "@typescript-eslint/parser": "^7.18.0",
+    "@typescript-eslint/eslint-plugin": "^8.0.0",
+    "@typescript-eslint/parser": "^8.0.0",
     "eslint": "^9.8.0",
     "eslint-config-prettier": "^9.1.0",
     "eslint-plugin-prettier": "^5.2.1",
     "globals": "^15.8.0",
     "husky": "^9.1.4",
     "jest": "^29.7.0",
-    "pg-mem": "^2.8.1",
+    "pg-mem": "^2.9.1",
     "plop": "^4.0.1",
     "prettier": "^3.3.3",
     "source-map-support": "^0.5.21",

src/app.module.ts

@@ -5,6 +5,7 @@ import { GraphQLModule } from '@nestjs/graphql';
 import { TypeOrmModule } from '@nestjs/typeorm';
 
 import { AuthModule } from './auth/auth.module';
+import { CustomCacheModule } from './cache/custom-cache.module';
 import { getEnvPath } from './common/helper/env.helper';
 import { SettingService } from './common/shared/services/setting.service';
 import { SharedModule } from './common/shared/shared.module';
@@ -35,6 +36,7 @@ import { UserModule } from './user/user.module';
     AuthModule,
     UploadModule,
     HealthModule,
+    CustomCacheModule.forRoot(),
   ],
 })
 export class AppModule {}

src/cache/custom-cache-interceptor.ts

@@ -0,0 +1,56 @@
+import {
+  CallHandler,
+  ExecutionContext,
+  Injectable,
+  NestInterceptor,
+} from '@nestjs/common';
+import { Reflector } from '@nestjs/core';
+import { GqlExecutionContext } from '@nestjs/graphql';
+
+import { Observable, lastValueFrom } from 'rxjs';
+
+import { CUSTOM_CACHE, CustomCacheOptions } from './custom-cache.decorator';
+import { CustomCacheService } from './custom-cache.service';
+
+@Injectable()
+export class CustomCacheInterceptor implements NestInterceptor {
+  constructor(
+    private readonly customCacheService: CustomCacheService,
+    private readonly reflector: Reflector,
+  ) {}
+
+  async intercept(
+    context: ExecutionContext,
+    next: CallHandler,
+  ): Promise<Observable<any>> {
+    const handler = context.getHandler();
+    const options = this.reflector.get<CustomCacheOptions>(
+      CUSTOM_CACHE,
+      handler,
+    );
+
+    if (!options) {
+      return next.handle();
+    }
+
+    const args = this.getArgs(context);
+
+    const customKey = `${context.getClass().name}.${handler.name}`;
+    const result = async () => await lastValueFrom(next.handle());
+
+    await this.customCacheService.setCache({
+      options,
+      args,
+      result,
+      customKey,
+    });
+
+    return next.handle();
+  }
+
+  private getArgs(context: ExecutionContext): unknown[] {
+    const ctx = GqlExecutionContext.create(context);
+    const req = ctx.getContext().req;
+    return req.body;
+  }
+}

src/cache/custom-cache.decorator.ts

@@ -0,0 +1,13 @@
+import { SetMetadata } from '@nestjs/common';
+
+export const CUSTOM_CACHE = Symbol('CUSTOM_CACHE');
+export interface CustomCacheOptions {
+  key?: string;
+
+  ttl?: number;
+
+  logger?: (...args: unknown[]) => unknown;
+}
+
+export const CustomCache = (options: CustomCacheOptions = {}) =>
+  SetMetadata(CUSTOM_CACHE, options);

src/cache/custom-cache.module.ts

@@ -0,0 +1,27 @@
+import { CacheModule, CacheModuleOptions } from '@nestjs/cache-manager';
+import { DynamicModule, Module, OnModuleInit } from '@nestjs/common';
+import { APP_INTERCEPTOR, DiscoveryModule } from '@nestjs/core';
+
+import { CustomCacheInterceptor } from './custom-cache-interceptor';
+import { CustomCacheService } from './custom-cache.service';
+
+@Module({})
+export class CustomCacheModule implements OnModuleInit {
+  constructor(private readonly customCacheService: CustomCacheService) {}
+
+  static forRoot(options?: CacheModuleOptions): DynamicModule {
+    return {
+      module: CustomCacheModule,
+      imports: [CacheModule.register(options), DiscoveryModule],
+      providers: [
+        CustomCacheService,
+        { provide: APP_INTERCEPTOR, useClass: CustomCacheInterceptor },
+      ],
+      global: true,
+    };
+  }
+
+  onModuleInit() {
+    this.customCacheService.registerAllCache();
+  }
+}

src/cache/custom-cache.service.ts

@@ -0,0 +1,85 @@
+import { CACHE_MANAGER, Cache } from '@nestjs/cache-manager';
+import { Inject, Injectable } from '@nestjs/common';
+import { DiscoveryService, MetadataScanner, Reflector } from '@nestjs/core';
+
+import { CUSTOM_CACHE, CustomCacheOptions } from './custom-cache.decorator';
+
+@Injectable()
+export class CustomCacheService {
+  constructor(
+    private readonly discoveryService: DiscoveryService,
+    private readonly metadataScanner: MetadataScanner,
+    private readonly reflector: Reflector,
+    @Inject(CACHE_MANAGER)
+    private readonly cacheManager: Cache,
+  ) {}
+
+  registerAllCache() {
+    return this.discoveryService
+      .getProviders()
+      .filter((wrapper) => wrapper.isDependencyTreeStatic())
+      .filter(({ instance }) => instance && Object.getPrototypeOf(instance))
+      .forEach(({ instance }) => {
+        const prototype = Object.getPrototypeOf(instance);
+        const methods = this.metadataScanner.getAllMethodNames(prototype);
+
+        methods.forEach(this.registerCache(instance));
+      });
+  }
+
+  private registerCache(instance: object) {
+    return (methodName: string) => {
+      const methodRef = instance[methodName];
+
+      const options = this.reflector.get<CustomCacheOptions>(
+        CUSTOM_CACHE,
+        methodRef,
+      );
+      if (!options) {
+        return;
+      }
+
+      const customKey = `${instance.constructor.name}.${methodName}`;
+
+      const methodOverride = async (...args: unknown[]) => {
+        const result = async () => await methodRef.apply(instance, args);
+
+        return this.setCache({ customKey, options, result, args });
+      };
+
+      Object.defineProperty(instance, methodName, {
+        value: methodOverride.bind(instance),
+      });
+    };
+  }
+
+  async setCache({
+    options,
+    args,
+    result: _result,
+    customKey,
+  }: {
+    options: CustomCacheOptions;
+    args: unknown[];
+    result: () => Promise<unknown>;
+    customKey: string;
+  }) {
+    const { key: cacheKey = customKey, ttl = Infinity, logger } = options;
+
+    const argsAddedKey = cacheKey + JSON.stringify(args);
+
+    const cachedValue = await this.cacheManager.get(argsAddedKey);
+    if (Boolean(cachedValue)) {
+      logger?.('Cache Hit', { cacheKey });
+
+      return cachedValue;
+    }
+
+    const result = await _result();
+
+    await this.cacheManager.set(argsAddedKey, result, ttl);
+    logger?.('Cached', { cacheKey });
+
+    return result;
+  }
+}

src/graphql-schema.gql

@@ -16,9 +16,7 @@ A date-time string at UTC, such as 2019-12-03T09:54:33Z, compliant with the date
 scalar DateTime
 
 input GetManyInput {
-  """
-  count or data or all, default = data
-  """
+  """count or data or all, default = data"""
   dataType: String
 
   """
@@ -39,14 +37,10 @@ type GetUserType {
 }
 
 input IPagination {
-  """
-  Started from 0
-  """
+  """Started from 0"""
   page: Int!
 
-  """
-  Size of page
-  """
+  """Size of page"""
   size: Int!
 }
 
@@ -98,9 +92,7 @@ input UpdateUserInput {
   username: String
 }
 
-"""
-The `Upload` scalar type represents a file upload.
-"""
+"""The `Upload` scalar type represents a file upload."""
 scalar Upload
 
 type User {
@@ -111,4 +103,4 @@ type User {
   role: String!
   updatedAt: DateTime!
   username: String!
-}
+}

src/user/user.resolver.ts

@@ -2,6 +2,7 @@ import { Args, Mutation, Query, Resolver } from '@nestjs/graphql';
 
 import GraphQLJSON from 'graphql-type-json';
 
+import { CustomCache } from 'src/cache/custom-cache.decorator';
 import { UseAuthGuard } from 'src/common/decorators/auth-guard.decorator';
 import { CurrentQuery } from 'src/common/decorators/query.decorator';
 import { GetManyInput, GetOneInput } from 'src/common/graphql/custom.input';
@@ -17,6 +18,7 @@ export class UserResolver {
 
   @Query(() => GetUserType)
   @UseAuthGuard('admin')
+  @CustomCache({ logger: console.log, ttl: 1000 })
   getManyUserList(
     @Args({ name: 'input', nullable: true })
     qs: GetManyInput<User>,

src/user/user.service.ts

@@ -1,5 +1,6 @@
 import { Injectable } from '@nestjs/common';
 
+import { CustomCache } from 'src/cache/custom-cache.decorator';
 import { OneRepoQuery, RepoQuery } from 'src/common/graphql/types';
 
 import { User } from './entities/user.entity';
@@ -10,6 +11,7 @@ import { UserRepository } from './user.repository';
 export class UserService {
   constructor(private readonly userRepository: UserRepository) {}
 
+  @CustomCache({ logger: console.log, ttl: 1000 })
   getMany(qs: RepoQuery<User> = {}, gqlQuery?: string) {
     return this.userRepository.getMany(qs, gqlQuery);
   }