Call ID

Get the location from where you're called from; a minimalist approach.

Supports both V8 (Chrome, Edge, Opera, NodeJS) and SpiderMonkey (FireFox).

🗺 Install

Install with npm or yarn:

npm i call-id
# OR
yarn add call-id

This package comes with its TypeScript type declarations included.

🎁 Example

// file.js
import { getCallId } from 'call-id';

function it(title, fn) {
  const { file, line, column } = getCallId();
  // file: file.js, line: 9, column: 0
}

it('should work', () => {}); // <-- this is line 9

The getCallId function is available in 3 ways:

• An es module: import { getCallId } from 'call-id'
• A cjs module: const { getCallId } = require('call-id')
• A browser script bundle: <script src="node_modules/call-id/dist/browser/index.js"> and use const { getCallId } = window.callId;

🤯 Why?

Test frameworks might be interested in where you're tests get declared. They can provide a richer user experience. For example, point you to the exact location where your failing tests can be found.

📖 API reference

getCallId(distance: number = 1): CallId | null

Gets the location from where you're called. This returns null if the provided distance exceeds the call stack, or couldn't be found otherwise.

You can provide a distance (default is 1) of larger then 1 if you want to go even further back on the call stack. Use 0 to receive the exact location from where you called getCallId.

CallId

A CallId object is returned from getCallId.

/**
 * Represents a call location
 */
interface CallId {
  /**
   * The file name or URL of the call location.
   */
  file: string;
  /**
   * The column number of the call location (or `0` if couldn't be determined).
   */
  column: number;
  /**
   * The line number of the call location (starts at `1`)
   */
  line: number;
}