inspect()

Returns a formatted string representation of a value without printing.

Syntax

inspect(value: unknown, options?: InspectOptions): string

Parameters

Parameter	Type	Description
value	unknown	The value to inspect
options	InspectOptions	Configuration options (optional)

Return value

Returns a formatted string ready to be used as you wish.

Options

Option	Type	Default	Description
view	'flat' | 'tree' | 'table'	'flat'	Visualisation style
depth	number	30	Maximum nesting depth
colors	boolean	auto	true = force colors, false = no colors, auto = TTY-based
showHidden	boolean	false	Show non-enumerable properties
maxArrayLength	number	1000	Maximum array items to display
maxStringLength	number	5000	Maximum string length
indent	number	2	Spaces per indentation level

Examples

Basic usage (flat view)

const output = inspect({ name: 'John', age: 30 });
console.log(output);
// { name: "John", age: 30 }

Tree view

const tree = inspect(data, { view: 'tree' });
console.log(tree);
// Object
// ├── name: "John"
// └── age: 30

Table view (array of objects)

const users = [
  { name: 'Alice', age: 30 },
  { name: 'Bob', age: 25 }
];
const table = inspect(users, { view: 'table' });
console.log(table);
// name   | age
// ───────┼─────
// Alice  | 30
// Bob    | 25

Save to file

import { inspect } from 'dumpkit';
import { writeFileSync } from 'fs';

const state = { users: 150, active: true };
writeFileSync('debug.json', inspect(state, { colors: false }));

Send via HTTP

import { inspect } from 'dumpkit';

app.get('/debug/state', (req, res) => {
  const debug = inspect(app.state);
  res.json({ debug });
});

Unit tests

import { inspect } from 'dumpkit';

test('should return correct structure', () => {
  const result = myFunction();
  const output = inspect(result, { colors: false });
  expect(output).toContain('property: "value"');
});

Difference between inspect() and dump()

Function	Returns string?	Prints to terminal?	Side effects
inspect()	✅ Yes	❌ No	None (pure)
dump()	❌ No	✅ Yes	Writes to stream

Why use inspect()?

• Pure function - no side effects
• Multiple views - flat, tree, table for different needs
• Reusable - same formatting for different destinations
• Testable - easy to verify output in tests
• Extensible - build your own tools on top

Tips

• Use inspect() when you need the string for processing
• Use dump() when you just want to quickly see the value
• Disable colors (colors: false) when saving to files or sending via HTTP
• Use view: 'tree' to understand nested structures
• Use view: 'table' for arrays of homogeneous objects