{"id":14680,"library":"lodash._basefindindex","title":"Lodash Internal `baseFindIndex` Module (v3.6.0)","description":"This package, `lodash._basefindindex`, provides a standalone CommonJS module for the internal `baseFindIndex` function from Lodash version 3.6.0. This function is an integral part of Lodash's core, designed to find the index of an element within a collection using a predicate, without directly exposing it as a public API method. In its original context, such modular builds allowed for more granular imports and smaller bundle sizes before widespread adoption of ES Modules and advanced tree-shaking capabilities. However, the main Lodash library is now at version 4.18.1, with its v3.x line officially reaching end-of-life in January 2016. Consequently, `lodash._basefindindex` (v3.6.0) is considered an abandoned, legacy package, and its use is generally discouraged in modern JavaScript development in favor of the full `lodash` or `lodash-es` packages, which benefit from active maintenance and regular security updates.","status":"abandoned","version":"3.6.0","language":"javascript","source_language":"en","source_url":"https://github.com/lodash/lodash","tags":["javascript"],"install":[{"cmd":"npm install lodash._basefindindex","lang":"bash","label":"npm"},{"cmd":"yarn add lodash._basefindindex","lang":"bash","label":"yarn"},{"cmd":"pnpm add lodash._basefindindex","lang":"bash","label":"pnpm"}],"dependencies":[],"imports":[{"note":"This package is a CommonJS module from Lodash v3.x and does not support ES module `import` syntax. For modern applications, use `_.findIndex` from the main `lodash` package or `lodash-es`.","wrong":"import baseFindIndex from 'lodash._basefindindex';","symbol":"baseFindIndex","correct":"const baseFindIndex = require('lodash._basefindindex');"},{"note":"The public equivalent `_.findIndex` should be imported from `lodash-es` for tree-shaking or directly from `lodash/findIndex` for CommonJS builds in modern Lodash (v4+). This `_basefindIndex` module is an internal function from v3.x.","wrong":"const { findIndex } = require('lodash._basefindindex');","symbol":"findIndex (modern equivalent)","correct":"import { findIndex } from 'lodash-es';\n// OR\nimport findIndex from 'lodash/findIndex';"},{"note":"The internal `_basefindIndex` is not directly exposed on the main `_` object. Use the public `_.findIndex` method instead.","wrong":"const { _basefindIndex } = require('lodash');","symbol":"lodash (main library)","correct":"const _ = require('lodash');\n_.findIndex(array, predicate);"}],"quickstart":{"code":"const baseFindIndex = require('lodash._basefindindex');\n\nconst users = [\n  { 'user': 'barney', 'active': false },\n  { 'user': 'fred',   'active': false },\n  { 'user': 'pebbles', 'active': true }\n];\n\n// Find the index of the first active user\nconst predicate = (o) => o.active;\nconst index = baseFindIndex(users, predicate, 0, false);\n\nconsole.log(`Index of first active user: ${index}`);\n\n// Example of how you would use the modern public API (not this package)\nconst _ = require('lodash');\nconst modernIndex = _.findIndex(users, predicate);\nconsole.log(`Index using modern _.findIndex: ${modernIndex}`);","lang":"javascript","description":"Demonstrates how to import and use the `baseFindIndex` function from this legacy module. It also contrasts it with the equivalent public API usage in modern Lodash."},"warnings":[{"fix":"Migrate to the main `lodash` package (v4.18.1 or newer) or `lodash-es` for modern usage. Use `_.findIndex` or `_.findLastIndex`.","message":"This `lodash._basefindindex` package is derived from Lodash v3.6.0. The v3.x line officially reached End-of-Life (EOL) in January 2016. It is no longer actively maintained for bug fixes, performance improvements, or security updates.","severity":"breaking","affected_versions":"3.x"},{"fix":"Avoid mixing different major versions of Lodash components. Upgrade all Lodash-related dependencies to v4+.","message":"Using this v3.x internal module alongside modern Lodash (v4+) may lead to compatibility issues, unexpected behavior, or performance regressions due to internal API changes between major versions.","severity":"breaking","affected_versions":">=3.6.0"},{"fix":"Always use `require()` for this specific package: `const baseFindIndex = require('lodash._basefindindex');`.","message":"This package exports a CommonJS module and does not natively support ES module `import` syntax. Attempting to use `import baseFindIndex from 'lodash._basefindindex'` will result in runtime errors.","severity":"gotcha","affected_versions":"3.x"},{"fix":"For smaller bundle sizes with modern tooling, use `lodash-es` and import specific methods: `import { findIndex } from 'lodash-es';`.","message":"Modern JavaScript bundlers with tree-shaking capabilities (e.g., Webpack, Rollup) can effectively optimize `lodash-es` imports, making these granular, pre-ESM internal modules obsolete and potentially counterproductive for bundle size optimization.","severity":"gotcha","affected_versions":"3.x"}],"env_vars":null,"last_verified":"2026-04-19T00:00:00.000Z","next_check":"2026-07-18T00:00:00.000Z","problems":[{"fix":"Change the import statement to `const baseFindIndex = require('lodash._basefindindex');`.","cause":"Attempting to use ES module `import` syntax (e.g., `import baseFindIndex from 'lodash._basefindindex'`) instead of CommonJS `require()` for this v3.x package.","error":"TypeError: baseFindIndex is not a function"},{"fix":"Ensure your environment supports CommonJS modules (e.g., Node.js) or use a bundler (like Webpack or Rollup) configured for CommonJS. Alternatively, switch to `lodash-es` for ES module compatibility.","cause":"Trying to use `require()` in an ES module context without proper transpilation or configuration, or directly in a browser without a CommonJS loader.","error":"ReferenceError: require is not defined"},{"fix":"Carefully review the function signature and expected argument types for `lodash._basefindindex` (v3.x) and ensure the inputs are valid. Refer to the Lodash v3 documentation for precise API details.","cause":"Incorrect arguments passed to `baseFindIndex`, such as `array` being `undefined` or `null`, or the predicate function not being callable, which can happen if you incorrectly assume v4 behavior with this v3 module.","error":"TypeError: Cannot read properties of undefined (reading 'length')"}],"ecosystem":"npm"}