{"id":10515,"library":"arrayreduce","title":"Array Reducing Utilities","description":"The `arrayreduce` package, currently at version 2.1.0, provides a small collection of pre-built, reusable reducer functions designed to simplify common array reduction patterns when used with JavaScript's native `Array.prototype.reduce` method. These utilities include functions for tasks such as concatenating nested arrays, performing logical AND/OR operations across array elements, and transforming an array of objects into an indexed object based on a specified attribute. Due to its last update approximately five years ago, the package is considered abandoned, lacks active maintenance, and does not provide native ES module (ESM) support or TypeScript type definitions. It targets older Node.js environments (>=4.0.0), making it less ideal for contemporary JavaScript projects without appropriate transpilation or CJS-to-ESM bridging solutions.","status":"abandoned","version":"2.1.0","language":"javascript","source_language":"en","source_url":"https://github.com/okunishinishi/node-arrayreduce","tags":["javascript","array","sort"],"install":[{"cmd":"npm install arrayreduce","lang":"bash","label":"npm"},{"cmd":"yarn add arrayreduce","lang":"bash","label":"yarn"},{"cmd":"pnpm add arrayreduce","lang":"bash","label":"pnpm"}],"dependencies":[],"imports":[{"note":"This package is a CommonJS module. Attempting to use default ES module import syntax will likely result in an error or an 'undefined' import without a CJS-ESM compatibility layer.","wrong":"import arrayreduce from 'arrayreduce';","symbol":"arrayreduce","correct":"const arrayreduce = require('arrayreduce');"},{"note":"Individual utility functions are exported as properties of the main CommonJS module. Direct named ES module imports are not supported.","wrong":"import { arrayConcat } from 'arrayreduce';","symbol":"arrayConcat","correct":"const { arrayConcat } = require('arrayreduce');"},{"note":"Access named exports via object destructuring from the `require()` call, not ES module named imports.","wrong":"import { indexByAttr } from 'arrayreduce';","symbol":"indexByAttr","correct":"const { indexByAttr } = require('arrayreduce');"}],"quickstart":{"code":"const arrayreduce = require('arrayreduce');\n\n// Get a reducer function to index an array of objects by an attribute.\nconst indexById = arrayreduce.indexByAttr('id');\n\n// Sample data\nconst data = [\n    {id: 101, name: 'Alice', age: 30},\n    {id: 102, name: 'Bob', age: 24},\n    {id: 103, name: 'Charlie', age: 35}\n];\n\n// Execute the reduction to create an indexed object\nconst indexedResult = data.reduce(indexById, {});\n\nconsole.log(indexedResult);\n/*\nOutput:\n{\n  '101': { id: 101, name: 'Alice', age: 30 },\n  '102': { id: 102, name: 'Bob', age: 24 },\n  '103': { id: 103, name: 'Charlie', age: 35 }\n}\n*/\n\n// Another example: Boolean AND reduction\nconst booleanAndReducer = arrayreduce.booleanAnd();\nconst andResult = [true, false, true].reduce(booleanAndReducer, true);\nconsole.log('Boolean AND result:', andResult); // -> Boolean AND result: false","lang":"javascript","description":"Demonstrates importing the module and using `indexByAttr` to create an object indexed by ID, along with a simple boolean reduction."},"warnings":[{"fix":"Evaluate alternatives like lodash/fp or implement custom reducer functions that suit your project's needs. If continued use is necessary, vendoring the code might be an option, but this is generally not recommended due to security and maintenance overheads.","message":"This package is considered abandoned, with the last commit dating back approximately five years. There will be no further updates, bug fixes, or security patches. Projects should consider migrating to maintained alternatives or implementing similar utility functions natively.","severity":"breaking","affected_versions":">=2.1.0"},{"fix":"Always use `const arrayreduce = require('arrayreduce');` for importing. In modern Node.js ESM projects, you might need to use dynamic `import()` or an ESM wrapper if strict ESM is enforced.","message":"The package is a CommonJS (CJS) module and does not natively support ES Modules (ESM) syntax. Direct `import` statements will fail in ESM-only environments or modern Node.js without specific configuration (e.g., Babel, Webpack, or a CJS-ESM bridge).","severity":"gotcha","affected_versions":">=2.0.0"},{"fix":"Create a custom declaration file (e.g., `arrayreduce.d.ts`) to provide type definitions for the functions you use. Alternatively, opt for type-safe alternatives.","message":"No TypeScript definitions are shipped with the package, nor are they available on DefinitelyTyped (`@types/arrayreduce`). This means TypeScript projects will infer `any` types for imported functions, losing type safety.","severity":"gotcha","affected_versions":">=2.0.0"},{"fix":"No direct fix is required for compatibility, but be aware that the code might not be optimized for current Node.js runtime performance or security features.","message":"The `package.json` specifies `\"node\": \">=4.0.0\"`. While this doesn't prevent it from running on newer Node.js versions, it indicates the package was developed for and tested against very old environments. It may not leverage modern JavaScript features or best practices.","severity":"gotcha","affected_versions":">=2.0.0"}],"env_vars":null,"last_verified":"2026-04-19T00:00:00.000Z","next_check":"2026-07-18T00:00:00.000Z","problems":[{"fix":"Convert your file to a CommonJS module (e.g., use `.js` extension without `\"type\": \"module\"`) or use dynamic `import('arrayreduce')` and then access the default export's properties.","cause":"Attempting to use `require()` in an ES module scope (e.g., in a file with `\"type\": \"module\"` in `package.json` or a `.mjs` file).","error":"ReferenceError: require is not defined"},{"fix":"Ensure you are using `const arrayreduce = require('arrayreduce');` for CommonJS imports, or, if in an ESM context, dynamically import it and destructure: `const { arrayConcat } = await import('arrayreduce');`.","cause":"This error typically occurs if `arrayreduce` was imported using `import arrayreduce from 'arrayreduce';` in an ESM context, which attempts to get a default export that doesn't exist, resulting in `arrayreduce` being `undefined` or an unexpected value.","error":"TypeError: arrayreduce.arrayConcat is not a function"},{"fix":"Create a `d.ts` file (e.g., `arrayreduce.d.ts`) in your project to declare the module and its functions, for example: `declare module 'arrayreduce' { export function arrayConcat(): Function; export function booleanAnd(): Function; export function booleanOr(): Function; export function indexByAttr(key: string): Function; }`","cause":"Using `arrayreduce` in a TypeScript project without type declarations.","error":"TS2307: Cannot find module 'arrayreduce' or its corresponding type declarations."}],"ecosystem":"npm"}