NodeJS Common Library

Name: @ducbaovn/nodejs-common
Current Version: 1.0.1

Connections

1. AMQP Connection:
- This class is for establish connection to AMQP server.
- Implementing publish-subscribe pattern for asynchronous inter-service communication among services
``
export declare class AmqpConnection {
protected channel: Channel;
protected config: AmqpConfig;
protected constructor(config?: AmqpConfig);
get connectionString(): string;
static connect(config?: AmqpConfig): Promise;
publishTopic(exchange: string, key: string, msg: string): Promise;
consumeTopic(exchange: string, keys: string[], cb: (msg: ConsumeMessage | null) => void): Promise;
}
`
2. MongoDB Connection:
- This class is for establish connection to MongoDB server.
- Using in service which do not need fixed schema and do not need strong consistency such as our activity-service
`
export declare class MongoDbConnection {
protected mongoClient: Db;
protected config: MongoDbConfig;
constructor(config?: MongoDbConfig);
getClient(): Db;
get connectionString(): string;
connect(): Promise;
}
`
3. MySQL Connection:
- This class is for establish connection to MySQL server.
- Using in service which need fixed-relational schema, strong consistency, such as our product-service
`
export declare class SqlConnection {
protected instance: Knex;
protected config: SqlConfig;
constructor(config?: SqlConfig);
migration(): Promise;
}
`

Enums

Sharing constants for all services

Errors

Custom Exception Class for consistent error http response
`
export declare class ApiError implements Error {
name: string;
stack: any;
message: string;
code: string;
httpStatus: number;
rawError: Error;
static fromError(error: Error, errorCode?: ErrorCode, httpStatus?: number, stack?: boolean): ApiError;
constructor(errorCode?: ErrorCode, httpStatus?: number, stack?: boolean);
toString(): string;
toErrorCode(): ErrorCode;
}
`

Middlewares

1. CORS: Set response headers to support CORS
2. Http Log: Logging Http Request Information: method, url, duration, http status, correlationId. We should use this middleware after Log Middleware
3. Log Middleware: init our custom Logger Service
4. Not Found Middleware: fallback to this middleware if route is not define in routers
5. Recover: fallback unhandled exception to our custom exception

Services

1. Logger Service: custom logger support correlationId
`
export declare class LoggerService {
private _level;
private _correlationId;
logger: winston.Logger;
constructor(options?: {
level: string;
correlationId?: string;
});
get correlationId(): string;
error(message: any, context?: any): void;
warn(message: any, context?: any): void;
log(message: any, context?: any): void;
verbose(message: any, context?: any): void;
debug(message: any, context?: any): void;
write(level: string, message: any, context?: any): void;
private format;
}
`

Utils

1. Request Helper:
- Wrapper of got library. It introduces simplier interface than got
- Use for synchronous inter-service communication between services
`
export interface ReqOptions {
body?: any;
headers?: any;
searchParams?: any;
basicAuth?: {
username: string;
password: string;
};
p12Auth?: {
pfx: Buffer;
passphrase: string;
};
timeout?: number;
retry?: number;
}
export declare class ResponseDto {
statusCode: number;
body: any;
headers: any;
constructor(statusCode: number, body: any, headers: any);
}
export declare class RequestHelper {
static get(url: string, options?: ReqOptions): Promise;
static post(url: string, body: any, options?: ReqOptions): Promise;
static put(url: string, body: any, options?: ReqOptions): Promise;
static delete(url: string, options?: ReqOptions): Promise;
static patch(url: string, body: any, options?: ReqOptions): Promise;
static stream(method: Method, url: string, options?: ReqOptions): Duplex;
static send(method: Method, url: string, options?: ReqOptions): Promise;
private static buildRequestParams;
private static transform;
}
``

Express Application

Wrapper Express Http Server. It has already installed some middlewares that I think they are will be used across services