n9-node-utils

Neo9 Node Utils Module.


Installation

``bash
npm install --save @neo9/n9-node-utils
`

or

`bash
yarn add --dev @neo9/n9-node-utils
`

$3

- Drop Node 8 support
- Rename N9JsonStreamResponse to N9JSONStreamResponse

Contents

- N9Error
- ok
- cb
- waitFor
- waitForEvent
- asyncObject

N9Error

Custom error class (extends Error), used by n9-node-micro for API errors with status code and context.

`ts
new N9Error(message [, statusCode] [, context])
`

Arguments:

- message: String, required
- status: Number, default: 500
- context: Object, default: {}

Example:

`ts
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.

`ts
ok(promise: Object): Promise
`

Arguments:

- promise: Promise

Example:

`ts
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.

`ts
cb(fn: Function, ...args: any[]): Promise
`

Arguments:

- fn: Function, a function that takes a callback
- args: (...any) arguments to pass to fn

Example:

`ts
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.

`ts
waitFor(ms: number): Promise
`

Arguments:

- ms: Number, default: 0

Example:

`ts
import { waitFor } from '@neo9/n9-node-utils';

await waitFor(1000); // wait for 1s
`

waitForEvent

Waits for emitter to emit an eventName event.

`ts
waitForEvent(emitter: EventEmitter, eventName: string): Promise
`

Arguments:

- emitter: EventEmitter
- eventName: String

Example:

`ts
import { waitForEvent } from '@neo9/n9-node-utils';

await waitForEvent(sever, 'listen');
`

asyncObject

Waits for all Promises in the keys of obj to resolve.

`ts
asyncObject(obj: Object): Promise