lang

lang holds the language-level utilities — the parts of the library that know nothing about Google Apps Script and run anywhere JavaScript does.

Packages

Package	Covers
`lang/base`	the `isX`/`nonX`/`requireX` guards for the built-in types
`lang/array`	array shape checks and transforms
`lang/number`	numeric classification and conversion
`lang/object`	hashing and string conversion
`lang/string`	case conversion, validation, and version comparison

The library also ships html, json, and time as sibling packages. They are runtime-independent in the same way and are listed alongside lang in Base utilities.

Type guards

lang/base is the largest package and the one most code touches. It is documented in full in Validation conventions; in short, isX and nonX answer questions, requireX validates and returns.

import { requireString, toKebabCase } from "apps-script-utils";

function slugify(input: unknown): string {
  return toKebabCase(requireString(input));
}

Arrays

import { chunk, transpose, is2DArray, isConsistent2DArray } from "apps-script-utils";

chunk([1, 2, 3, 4, 5], 2); // [[1, 2], [3, 4], [5]]

transpose([
  ["a", "b"],
  ["c", "d"]
]); // [["a", "c"], ["b", "d"]]

is2DArray([[1], [2]]); // true
isConsistent2DArray([[1, 2], [3]]); // false — rows differ in length

isConsistent2DArray is the check worth making before writing to a sheet: Range.setValues() requires every row to have the same length, and a ragged array fails at the service boundary with a message that does not say which row was wrong.

Numbers

import { isCountable, isFloat, isInteger, toInteger } from "apps-script-utils";

isInteger(42); // true
isInteger(42.5); // false
isFloat(42.5); // true
isCountable(3); // true — a non-negative whole number
isCountable(-1); // false

Row and column arguments in the Sheets API are counts, not arbitrary numbers, which is what isCountable and requireCountable are for.

Strings

Case conversion:

import { toCamelCase, toKebabCase, toSnakeCase, toProperCase } from "apps-script-utils";

toCamelCase("user name"); // "userName"
toKebabCase("User Name"); // "user-name"
toSnakeCase("User Name"); // "user_name"
toProperCase("user name"); // "User Name"

Validation:

import { isEmail, isValidSlug, isValidVersion, requireValidEmail } from "apps-script-utils";

isEmail("ada@example.com"); // true
isValidSlug("my-post"); // true
isValidVersion("1.10.0"); // true

requireValidEmail(formResponse); // returns it, or throws InvalidEmailFormatException

Version comparison, for scripts that gate behaviour on a library version:

import { versionCompare, isVersionCompatible } from "apps-script-utils";

versionCompare("1.10.0", "1.9.0"); // 1
versionCompare("1.9.0", "1.10.0"); // -1
versionCompare("1.9.0", "1.9.0"); // 0

escapeRegExp makes a user-supplied string safe to interpolate into a pattern — worth using whenever a search term comes from a cell or a form:

import { escapeRegExp } from "apps-script-utils";

const pattern = new RegExp(escapeRegExp(searchTerm), "gi");

Objects

import { hashCode, objectToString } from "apps-script-utils";

objectToString([]); // "[object Array]"
objectToString(null); // "[object Null]"
hashCode("apps-script-utils"); // a stable numeric hash

objectToString reports the internal tag rather than String(value), which makes it the reliable way to tell an array from a date from a plain object — and the tag survives crossing a frame boundary, where instanceof does not.

Full list

Base utilities lists every function in lang, html, json, and time with its return type and a link to its source.

23 September 2026

This documentation was generated with AI (Claude) from the library's source code.