neo9n9-node-utils
Neo9 Node Utils Module.
Installation
npm install --save @neo9/n9-node-utilsor
yarn add --dev @neo9/n9-node-utilsV2 Breaking changes
- Drop Node 8 support
- Rename
N9JsonStreamResponsetoN9JSONStreamResponse
Contents
N9Error
Custom error class (extends Error), used by n9-node-micro for API errors with status code and context.
new N9Error(message [, statusCode] [, context])Arguments:
- message:
String, required - status:
Number, default:500 - context:
Object, default:{}
Example:
import { N9Error } from '@neo9/n9-node-utils';
throw new N9Error('file-not-found', 404, { path: '/tmp/my-file.txt' });ok
Waits for the value of promise. If promise throws an Error, returns undefined.
ok(promise: Object): PromiseArguments:
- promise:
Promise
Example:
import { readFile } from 'fs-extra';
import { ok } from '@neo9/n9-node-utils';
// readFile sends back a Promise since we use fs-extra
const file = await ok(readFile('./my-file.txt', 'utf-8'));
if (file) console.log('File found:', file);cb
Calls a function fn that takes arguments args and an (err, result) callback. Waits for the callback result, throwing an Error if err is truthy.
cb(fn: Function, ...args: any[]): PromiseArguments:
- fn:
Function, a function that takes a callback - args: (...
any) arguments to pass tofn
Example:
import { cb } from '@neo9/n9-node-utils';
const file = await cb(readFile('./my-file.txt', 'utf-8'));
console.log('File content:', file);waitFor
Waits for ms milliseconds to pass, use setTimeout under the hood.
waitFor(ms: number): PromiseArguments:
- ms:
Number, default:0
Example:
import { waitFor } from '@neo9/n9-node-utils';
await waitFor(1000); // wait for 1swaitForEvent
Waits for emitter to emit an eventName event.
waitForEvent(emitter: EventEmitter, eventName: string): Promise<Array>Arguments:
- emitter:
EventEmitter - eventName:
String
Example:
import { waitForEvent } from '@neo9/n9-node-utils';
await waitForEvent(sever, 'listen');asyncObject
Waits for all Promises in the keys of obj to resolve.
asyncObject(obj: Object): Promise<Object>Arguments:
- obj:
Object, default:{}
Example:
import { asyncObject } from '@neo9/n9-node-utils';
const results = await asyncObject({
pictures: getPictures(),
comments: getComments(),
tweets: getTweets(),
});
console.log(results.pictures, results.comments, results.tweets);