{"id":12024,"library":"should-util","title":"should.js Utility Functions","description":"should-util is a foundational utility library within the should.js assertion ecosystem. It provides a collection of core helper functions, primarily type-checking utilities (e.g., `isString`, `isArray`, `isFunction`) and a `deepEqual` comparison function. The package itself is highly stable, having been at version 1.0.1 since its initial releases over a decade ago, with the last code commit occurring 7 years prior. As such, it follows a 'maintenance' release cadence, receiving no active development or new features. Its primary differentiator is its integral role in the should.js assertion library, offering common, reusable functionalities that are robust and well-tested, though not independently maintained for general-purpose use. It is predominantly a CommonJS module, reflecting its age.","status":"maintenance","version":"1.0.1","language":"javascript","source_language":"en","source_url":"https://github.com/shouldjs/util","tags":["javascript","shouldjs","util"],"install":[{"cmd":"npm install should-util","lang":"bash","label":"npm"},{"cmd":"yarn add should-util","lang":"bash","label":"yarn"},{"cmd":"pnpm add should-util","lang":"bash","label":"pnpm"}],"dependencies":[{"reason":"Provides a robust check for arguments objects.","package":"is-arguments","optional":false},{"reason":"Provides a robust check for arrays.","package":"is-array","optional":false},{"reason":"Provides a robust check for Node.js Buffer objects.","package":"is-buffer","optional":false},{"reason":"Provides a robust check for boolean values.","package":"lodash.isboolean","optional":false},{"reason":"Provides a robust check for Date objects.","package":"lodash.isdate","optional":false},{"reason":"Provides a robust check for Error objects.","package":"lodash.iserror","optional":false},{"reason":"Provides a robust check for function objects.","package":"lodash.isfunction","optional":false},{"reason":"Provides a robust check for number values.","package":"lodash.isnumber","optional":false},{"reason":"Provides a robust check for plain objects.","package":"lodash.isobject","optional":false},{"reason":"Provides a robust check for RegExp objects.","package":"lodash.isregexp","optional":false},{"reason":"Provides a robust check for string values.","package":"lodash.isstring","optional":false},{"reason":"Provides a robust check for null values.","package":"lodash.isnull","optional":false},{"reason":"Provides a robust check for undefined values.","package":"lodash.isundefined","optional":false}],"imports":[{"note":"While CommonJS `require` is the primary usage, modern bundlers can often convert this to ESM named imports. The package itself is a CJS module without `exports` field in package.json.","wrong":"const { isString } = require('should-util')","symbol":"isString","correct":"import { isString } from 'should-util'"},{"note":"The `deepEqual` function is a named export from the main entry point, not a default export or a direct submodule import.","wrong":"import deepEqual from 'should-util/lib/deepEqual'","symbol":"deepEqual","correct":"import { deepEqual } from 'should-util'"},{"note":"Destructuring is recommended for specific utility functions. Direct property access (e.g., `require('pkg').prop`) is functional but less idiomatic for multiple imports in modern JavaScript.","wrong":"const isArray = require('should-util').isArray","symbol":"isArray","correct":"import { isArray } from 'should-util'"}],"quickstart":{"code":"import { isString, isArray, deepEqual } from 'should-util';\n\n// Example 1: Type checking a string\nconst myString = 'Hello, world!';\nconsole.log(`'${myString}' is a string: ${isString(myString)}`);\n// Expected: 'Hello, world!' is a string: true\n\n// Example 2: Type checking an array\nconst myArray = [1, 2, 3];\nconsole.log(`${JSON.stringify(myArray)} is an array: ${isArray(myArray)}`);\n// Expected: [1,2,3] is an array: true\n\n// Example 3: Deep equality comparison\nconst objA = { a: 1, b: { c: 2 } };\nconst objB = { a: 1, b: { c: 2 } };\nconst objC = { a: 1, b: { c: 3 } };\n\nconsole.log(`objA deepEqual objB: ${deepEqual(objA, objB)}`);\n// Expected: objA deepEqual objB: true\nconsole.log(`objA deepEqual objC: ${deepEqual(objA, objC)}`);\n// Expected: objA deepEqual objC: false\n\n// Example 4: Demonstrating other exports\nimport util from 'should-util'; // For older bundlers or direct CommonJS require\nconsole.log(`Is null undefined? ${util.isUndefined(null)}`);\nconsole.log(`Is undefined undefined? ${util.isUndefined(undefined)}`);","lang":"typescript","description":"Demonstrates importing and using `isString`, `isArray`, and `deepEqual` for type checking and object comparison, key utilities from the package."},"warnings":[{"fix":"For direct CommonJS usage, use `const { utility } = require('should-util');`. For ES module usage in environments without strong CJS interop, ensure your build tool handles CJS packages or consider alternative, actively maintained utility libraries.","message":"The `should-util` package is primarily a CommonJS module. While modern bundlers can often convert `import` statements, it does not explicitly define ES module entry points using the `package.json#exports` field. This may lead to compatibility issues in pure ESM environments or older tooling.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Be aware that new features or bug fixes are unlikely. If using TypeScript, you will need to provide your own declaration files (`.d.ts`) or rely on implicit `any` typing. Consider the implications for long-term project viability.","message":"This package is in maintenance mode with no active development. The last commit was 7 years ago, and there have been no new releases in a decade. While stable, it lacks modern features, TypeScript definitions, or updates for newer JavaScript language constructs or environments.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Evaluate if a specific utility function is truly needed from `should-util` or if a native JavaScript method or a function from a more actively developed library would suffice.","message":"Many of the basic type-checking utilities (e.g., `isString`, `isArray`) provided by `should-util` have native JavaScript equivalents (e.g., `typeof ''`, `Array.isArray()`) or are readily available in more modern, actively maintained utility libraries (e.g., Lodash, Ramda). Over-reliance on this specific package for basic tasks might introduce an unnecessary, unmaintained dependency.","severity":"gotcha","affected_versions":">=1.0.0"}],"env_vars":null,"last_verified":"2026-04-19T00:00:00.000Z","next_check":"2026-07-18T00:00:00.000Z","problems":[{"fix":"Try importing the entire module as a default import and then accessing properties: `import util from 'should-util'; console.log(util.isString('test'))`. Alternatively, configure your bundler (e.g., Webpack, Rollup) to better handle CommonJS modules, or ensure `module.exports` is correctly identified as the source of named exports.","cause":"Attempting to use ES module named imports in a bundler that struggles with CJS interop, or directly in an environment that expects explicit ES exports. This usually means the bundler didn't correctly resolve `module.exports` to named imports.","error":"TypeError: (0 , should_util__WEBPACK_IMPORTED_MODULE_0__.isString) is not a function"},{"fix":"Ensure your project's module resolution (`tsconfig.json#moduleResolution`, `package.json#type`) is compatible with CommonJS modules. If you are in a pure ESM environment, you may need to use a dynamic `import()` or find an ESM-native alternative for the desired functionality.","cause":"This error would typically occur if `should-util` were an ESM package being `require()`d. However, `should-util` is CJS. If you encounter this, it likely means another dependency or the consuming project is configured as ESM-only, and the tooling is failing to correctly load `should-util` as CJS.","error":"Error [ERR_REQUIRE_ESM]: require() of ES Module ... Not supported by CommonJS 'require'."}],"ecosystem":"npm"}