OST Base provides advanced Promise Queue Manager and other utilities.

Install

npm install @ostdotcom/base --save

PromiseQueueManager Usage

const OSTBase = require('@ostdotcom/base'),
  logger  = new OSTBase.Logger("my_module_name");

const queueManagerOptions = {
  // Specify the name for easy identification in logs.
  name: "my_module_name_promise_queue"

  // resolvePromiseOnTimeout :: set this flag to false if you need custom handling.
  // By Default, the manager will neither resolve nor reject the Promise on time out.
  , resolvePromiseOnTimeout: false
  // The value to be passed to resolve when the Promise has timedout.
  , resolvedValueOnTimeout: null

  // rejectPromiseOnTimeout :: set this flag to true if you need custom handling.
  , rejectPromiseOnTimeout : false

  //  Pass timeoutInMilliSecs in options to set the timeout.
  //  If less than or equal to zero, timeout will not be observed.
  , timeoutInMilliSecs: 5000

  //  Pass maxZombieCount in options to set the max acceptable zombie count.
  //  When this zombie promise count reaches this limit, onMaxZombieCountReached will be triggered.
  //  If less than or equal to zero, onMaxZombieCountReached callback will not triggered.
  , maxZombieCount: 0

  //  Pass logInfoTimeInterval in options to log queue healthcheck information.
  //  If less than or equal to zero, healthcheck will not be logged.
  , logInfoTimeInterval : 0


  , onPromiseResolved: function ( resolvedValue, promiseContext ) {
    //onPromiseResolved will be executed when the any promise is resolved.
    //This callback method should be set by instance creator.
    //It can be set using options parameter in constructor.
    const oThis = this;

    logger.log(oThis.name, " :: a promise has been resolved. resolvedValue:", resolvedValue);
  }

  , onPromiseRejected: function ( rejectReason, promiseContext ) {
    //onPromiseRejected will be executed when the any promise is timedout.
    //This callback method should be set by instance creator.
    //It can be set using options parameter in constructor.
    const oThis = this;

    logger.log(oThis.name, " :: a promise has been rejected. rejectReason: ", rejectReason);
  }

  , onPromiseTimedout: function ( promiseContext ) {
    //onPromiseTimedout will be executed when the any promise is timedout.
    //This callback method should be set by instance creator.
    //It can be set using options parameter in constructor.
    const oThis = this;

    logger.log(oThis.name, ":: a promise has timed out.", promiseContext.executorParams);
  }

  , onMaxZombieCountReached: function () {
    //onMaxZombieCountReached will be executed when maxZombieCount >= 0 && current zombie count (oThis.zombieCount) >= maxZombieCount.
    //This callback method should be set by instance creator.
    //It can be set using options parameter in constructor.
    const oThis = this;

    logger.log(oThis.name, ":: maxZombieCount reached.");

  }

  , onPromiseCompleted: function ( promiseContext ) {
    //onPromiseCompleted will be executed when the any promise is removed from pendingPromise queue.
    //This callback method should be set by instance creator.
    //It can be set using options parameter in constructor.
    const oThis = this;

    logger.log(oThis.name, ":: a promise has been completed.");
  }  
  , onAllPromisesCompleted: function () {
    //onAllPromisesCompleted will be executed when the last promise in pendingPromise is resolved/rejected.
    //This callback method should be set by instance creator.
    //It can be set using options parameter in constructor.
    //Ideally, you should set this inside SIGINT/SIGTERM handlers.

    logger.log("Examples.allResolve :: onAllPromisesCompleted triggered");
    manager.logInfo();
  }
};


const promiseExecutor = function ( resolve, reject, params, promiseContext ) {
  //promiseExecutor
  setTimeout(function () {
    resolve( params.cnt ); // Try different things here.
  }, 1000);
};

const manager = new OSTBase.OSTPromise.QueueManager( promiseExecutor, queueManagerOptions);

for( let cnt = 0; cnt < 50; cnt++ ) {
  manager.createPromise( {"cnt": (cnt + 1) } );
}

Logger Usage

const OSTBase = require('@ostdotcom/base'),
  Logger  = OSTBase.Logger,
  logger  = new Logger("my_module_name", Logger.LOG_LEVELS.TRACE);

//Log Level FATAL 
logger.notify("notify called");

//Log Level ERROR
logger.error("error called");

//Log Level WARN
logger.warn("warn called");

//Log Level INFO
logger.info("info Invoked");
logger.step("step Invoked");
logger.win("win called");

//Log Level DEBUG
logger.log("log called");
logger.debug("debug called");
logger.dir({ l1: { l2 : { l3Val: "val3", l3: { l4Val: { val: "val"  }}} }});

//Log Level TRACE
logger.trace("trace called");

All methods will be available for use irrespcetive of configured log level. Log Level only controls what needs to be logged.

Method to Log Level Map

Method	Enabling Log Level
notify	FATAL
error	ERROR
warn	WARN
info	INFO
step	INFO
win	INFO
debug	DEBUG
log	DEBUG
dir	DEBUG
trace	TRACE

Response formatter usage

const rootPrefix = '.',
  paramErrorConfig = require(rootPrefix + '/tests/mocha/lib/formatter/param_error_config'),
  apiErrorConfig = require(rootPrefix + '/tests/mocha/lib/formatter/api_error_config');

const OSTBase = require('@ostdotcom/base'),
  ResponseHelper  = OSTBase.responseHelper,
  responseHelper = new ResponseHelper({
      moduleName: 'companyRestFulApi'
  });
    
//using error function
responseHelper.error({
  internal_error_identifier: 's_vt_1', 
  api_error_identifier: 'test_1',
  debug_options: {id: 1234},
  error_config: {
    param_error_config: paramErrorConfig,
    api_error_config: apiErrorConfig   
  }
});
    
//using paramValidationError function
responseHelper.paramValidationError({
  internal_error_identifier:"s_vt_2", 
  api_error_identifier: "test_1", 
  params_error_identifiers: ["user_name_inappropriate"], 
  debug_options: {id: 1234},
  error_config: {
    param_error_config: paramErrorConfig,
    api_error_config: apiErrorConfig   
  }
});

// Result object is returned from responseHelper method invocations above, we can chain several methods as shown below
    
responseHelper.error({
  internal_error_identifier: 's_vt_1', 
  api_error_identifier: 'invalid_api_params',
  debug_options: {id: 1234},
  error_config: {
    param_error_config: paramErrorConfig,
    api_error_config: apiErrorConfig   
  }
}).isSuccess();

responseHelper.error({
  internal_error_identifier: 's_vt_1', 
  api_error_identifier: 'invalid_api_params',
  debug_options: {id: 1234},
  error_config: {
    param_error_config: paramErrorConfig,
    api_error_config: apiErrorConfig   
  }
}).isFailure();

responseHelper.error({
  internal_error_identifier: 's_vt_1', 
  api_error_identifier: 'invalid_api_params',
  debug_options: {id: 1234},
  error_config: {
    param_error_config: paramErrorConfig,
    api_error_config: apiErrorConfig   
  }
}).toHash();