Lodash Internal pickByCallback Module

Common errors

• TypeError: pickByCallback is not a function

  cause The `lodash._pickbycallback` package is a CommonJS module. This error often occurs when attempting to use ES module `import` syntax or incorrect destructuring (e.g., `import { pickByCallback } from '...'`) which results in `undefined`.
  fix Ensure you are using the CommonJS `require` syntax: `const pickByCallback = require('lodash._pickbycallback');`.

• SyntaxError: Cannot use import statement outside a module

  cause You are trying to `import` this package in a CommonJS context (e.g., a `.js` file without `"type": "module"` in `package.json` or a `.cjs` file). This package is natively CommonJS.
  fix Change the import statement to a CommonJS `require` statement: `const pickByCallback = require('lodash._pickbycallback');`.

Warnings

• breaking This `lodash._pickbycallback` package is based on Lodash v3.x. The main Lodash library introduced significant breaking changes in v4.0.0, including changes to how `pick` and `pickBy` predicates receive arguments (initially not passing the key). Using this v3 package in a v4+ Lodash environment can lead to unexpected behavior or API mismatches.
  Fix: Migrate to modern Lodash usage by importing `pickBy` directly from the main `lodash` package (e.g., `require('lodash/pickBy')`) or `lodash-es` for ESM, ensuring compatibility with Lodash v4+ APIs.
• deprecated This 'per-method' package (`lodash._pickbycallback`) represents an outdated modularization strategy for Lodash. Its use is discouraged, and these packages are slated for removal in Lodash v5. Modern applications should prefer importing specific functions directly from the main `lodash` package or using `lodash-es` for better tree-shaking and maintainability.
  Fix: Refactor your imports to use `const pickBy = require('lodash/pickBy');` for CommonJS or `import { pickBy } from 'lodash-es';` for ESM, leveraging actively maintained Lodash builds.
• gotcha This package, being stuck at v3.0.0, does not include security patches or bug fixes released in later versions of the main Lodash library. For example, critical prototype pollution vulnerabilities fixed in `lodash@4.18.0` via `_.unset` and `_.omit` are not addressed in this package. Using outdated dependencies can expose your application to known security flaws.
  Fix: Upgrade to the actively maintained `lodash` package (v4.x or newer) and import `pickBy` from there. If specific legacy behavior is required, carefully audit the code for vulnerabilities or consider vendoring the function after applying necessary patches.

Install

• npm install lodash._pickbycallback npm
• yarn add lodash._pickbycallback yarn
• pnpm add lodash._pickbycallback pnpm

Imports

• pickByCallback

  var pickByCallback = require('lodash._pickbycallback');

  This package is CommonJS-only, typical for its v3.0.0 era. It does not support ES module `import` syntax.
• pickByCallback
  wrong:

  import { pickByCallback } from 'lodash._pickbycallback';

  correct:

  import pickByCallback from 'lodash._pickbycallback';

  While this package is CommonJS, some bundlers might attempt to 'shim' a default import. Named imports like `import { pickByCallback }` are incorrect as this package does not use named exports.

Quickstart

This code demonstrates how to import and use the `pickByCallback` function from the `lodash._pickbycallback` package in a CommonJS Node.js environment, filtering active users from an object.

const pickByCallback = require('lodash._pickbycallback');

const users = {
  'fred':    { 'user': 'fred',    'active': false },
  'barney':  { 'user': 'barney',  'active': true  },
  'pebbles': { 'user': 'pebbles', 'active': false }
};

const activeUsers = pickByCallback(users, (value) => value.active);

console.log(activeUsers);
// Expected output: { barney: { user: 'barney', active: true } }

const numbers = {
  'a': 1,
  'b': 0,
  'c': undefined
};

// Note: `pickByCallback` (equivalent to `_.pickBy`) by default treats 0, false, null, undefined as falsey and filters them.
const truthyNumbers = pickByCallback(numbers, (value) => !!value);
console.log(truthyNumbers);
// Expected output: { a: 1 }