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This codemod replaces the following deprecated util.is*() methods with their modern equivalents.

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What It Does

This codemod handles 15 deprecated type-checking methods:
  • util.isArray() → Array.isArray()
  • util.isBoolean() → typeof value === 'boolean'
  • util.isBuffer() → Buffer.isBuffer()
  • util.isDate() → value instanceof Date
  • util.isError() → Error.isError()
  • util.isFunction() → typeof value === 'function'
  • util.isNull() → value === null
  • util.isNullOrUndefined() → value === null || value === undefined
  • util.isNumber() → typeof value === 'number'
  • util.isObject() → value && typeof value === 'object'
  • util.isPrimitive() → Object(value) !== value
  • util.isRegExp() → value instanceof RegExp
  • util.isString() → typeof value === 'string'
  • util.isSymbol() → typeof value === 'symbol'
  • util.isUndefined() → typeof value === 'undefined'

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Before/After Examples

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Type Checks

Before:
After:

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Object Type Checks

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After:

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Null/Undefined Checks

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After:

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Usage

Run this codemod on your project:
Modern JavaScript provides native type-checking mechanisms that are more performant and widely understood. These standard approaches are preferred over Node.js-specific utilities.