Object Inspection Utility

Common errors

• TypeError: inspect is not a function

  cause The `inspect` function was not correctly imported or required into the current module context.
  fix In CommonJS modules, use `const inspect = require('object-inspect');`. In ES Modules, use `import inspect from 'object-inspect';`. Verify module type configuration if using TypeScript.

• Object output is truncated or lacks detail (e.g., `[Object]`, `[Array]`, or short strings)

  cause The default `depth` or `maxStringLength` options are limiting the output's detail, or you have not explicitly configured them for your needs.
  fix Increase the `depth` option (e.g., `inspect(obj, { depth: Infinity })` for full depth) and/or adjust `maxStringLength` (e.g., `inspect(obj, { maxStringLength: null })` for no string truncation) in the `inspect` function call.

Warnings

• gotcha The `customInspect` option, introduced in v1.8.0, defaults to `true`. This means if an object has a `Symbol.for('nodejs.util.inspect.custom')` method or an `inspect` property (for compatibility), it will be invoked. If you intend to bypass custom inspect methods and always get `object-inspect`'s default string representation, set `customInspect: false`.
  Fix: Use `inspect(obj, { customInspect: false })` to ignore custom inspect methods, or `inspect(obj, { customInspect: 'symbol' })` to only respect symbol-based custom methods.
• gotcha `object-inspect` aims for compatibility with Node.js's `util.inspect` but is a separate, cross-environment utility. Its output may not always perfectly mirror the exact string representation provided by Node.js's built-in `util.inspect`, especially with evolving Node.js versions or highly specific edge cases.
  Fix: For critical Node.js-specific inspection, prefer `require('util').inspect` if the environment is guaranteed to be Node.js. Use `object-inspect` when cross-environment consistency or specific custom options are prioritized.
• gotcha When inspecting DOM elements in a browser environment, `object-inspect` provides a concise representation (e.g., `<div id="beep">...</div>`). It does not perform full HTML serialization or provide detailed child node information beyond an ellipsis for brevity.
  Fix: If detailed HTML or full DOM tree serialization is required, use browser-native APIs like `element.outerHTML` or `new XMLSerializer().serializeToString(document)`.

Install

• npm install object-inspect npm
• yarn add object-inspect yarn
• pnpm add object-inspect pnpm

Imports

• inspect
  wrong:

  import inspect from 'object-inspect';

  correct:

  const inspect = require('object-inspect');

  This is the correct CommonJS `require` pattern for Node.js environments. The package is primarily CJS-first, supporting Node.js versions as old as 0.4.
• inspect
  wrong:

  const inspect = require('object-inspect');

  correct:

  import inspect from 'object-inspect';

  For ES Modules, `import inspect from 'object-inspect'` is the standard. If using TypeScript, ensure `esModuleInterop` is enabled in `tsconfig.json` for proper type resolution; otherwise, you might need `import inspect = require('object-inspect');`.

Quickstart

Demonstrates `object-inspect`'s ability to handle circular references, control output depth and formatting, and serialize various built-in and primitive types like BigInt, Date, and Map.

const inspect = require('object-inspect');

// Example 1: Circular reference handling
const obj = { a: 1, b: [3, 4] };
obj.c = obj;
console.log('Circular object:', inspect(obj));
// Expected output: Circular object: { a: 1, b: [ 3, 4 ], c: [Circular] }

// Example 2: Deep object with truncation and custom quote style
const deepObj = {
  a: {
    b: {
      c: [1, 2, { d: 'hello world string longer than max length example' }],
    },
  },
  func: function myFunc() {},
  sym: Symbol('test'),
};
console.log('\nDeep object (default):', inspect(deepObj));
console.log('Deep object (depth=2, maxStringLength=10, quoteStyle=\'single\'):', inspect(deepObj, {
  depth: 2,
  maxStringLength: 10,
  quoteStyle: 'single'
}));

// Example 3: BigInt, Date, and Map objects with numeric separators and indent
const mixedData = {
  id: 123456789012345678901234567890n, // BigInt
  date: new Date('2023-10-26T10:00:00Z'),
  map: new Map([['key1', 'val1'], ['key2', 'val2']]),
};
console.log('\nMixed data (numericSeparator=true, indent=\'  \'):', inspect(mixedData, {
  numericSeparator: true,
  indent: '  '
}));