@zuke/qr

`@zuke/qr` — QR codes for any data, from a Zuke build, with no dependency.

Symbols

ErrorCorrectionLevel

type

type ErrorCorrectionLevel = L | M | Q | H

A QR error-correction level, from "L" (~7% recoverable) to "H" (~30%).

MAX_QUIET_ZONE

const

const MAX_QUIET_ZONE: 16

The widest quiet zone accepted; the specification asks for 4.

QrCapacityError

class

class QrCapacityError extends Error

Thrown when the text does not fit the largest symbol at the requested level.

Member	Signature	Doc
`name`	`name: string`	The error's class name, for `instanceof`-free identification.

QrCode

interface

interface QrCode

A finished QR code, as the caller sees it.

Member	Signature	Doc
`version`	`version: number`	The symbol version (1–40).
`size`	`size: number`	The side length in modules (`version * 4 + 17`).
`errorCorrection`	`errorCorrection: ErrorCorrectionLevel`	The error-correction level actually used (boosting can raise the requested one).
`mask`	`mask: number`	The mask pattern (0–7) the penalty score selected.
`modules`	`modules: unknown`	The modules, `modules[y][x]`, `true` for dark.

QrPrintOptions

interface

interface QrPrintOptions

Options for QrTasks.print beyond the settings lambda.

Member	Signature	Doc
`write?`	`write?: unknown`	Where each rendered line goes (default `console.log`).

QrSettings

class

class QrSettings

Configuration for encoding and rendering a QR code, set through a lambda passed to a QrTasks method. Every setter returns this so calls chain.

Member	Signature	Doc
`errorCorrection`	`errorCorrection(level: ErrorCorrectionLevel): this`	Set the error-correction level: `"L"` (~7%), `"M"` (~15%), `"Q"` (~25%) or `"H"` (~30%).
`boostErrorCorrection`	`boostErrorCorrection(enabled?: boolean): this`	Whether to raise the error-correction level when a higher one fits the same version. On by default; turn it off to get exactly the level asked for.
`quietZone`	`quietZone(modules: number): this`	Set the width of the light border around the symbol, in modules (0 to `MAX_QUIET_ZONE`).
`invert`	`invert(enabled?: boolean): this`	Swap the colours: light modules become blocks and dark ones spaces. Use it on a terminal whose text is light on dark, where the default rendering shows the code with dark and light exchanged.
`compact`	`compact(enabled?: boolean): this`	Whether to draw two module rows per line with `▀`/`▄`/`█` (the default, which keeps a version-3 code under 20 lines) or one row per line with a two-character `██` cell per module.
`errorCorrection_`	`errorCorrection_: ErrorCorrectionLevel`	The requested error-correction level (default `"M"`).
`boostErrorCorrection_`	`boostErrorCorrection_: boolean`	Raise the level for free when the chosen version has room (default `true`).
`quietZone_`	`quietZone_: number`	Light modules drawn around the symbol, in modules (default 2; the spec asks for 4).
`invert_`	`invert_: boolean`	Draw dark modules as spaces and light ones as blocks (default `false`).
`compact_`	`compact_: boolean`	Pack two module rows into one text line with half-block characters (default `true`).

QrTasks

const

const QrTasks: QrTasksApi

Task-shaped QR code operations. Each method takes the text to encode (a URL, usually) and an optional settings lambda:

import { QrTasks } from "@zuke/qr";

QrTasks.print("https://zuke.build", (s) => s.errorCorrection("Q"));

QrTasksApi

interface

interface QrTasksApi

The surface of QrTasks.

Member	Signature	Doc
`encode`	`encode(text: string, configure?: Configure<QrSettings>): QrCode`	Encode `text` (as UTF-8, byte mode) into a `QrCode` matrix.
`renderLines`	`renderLines(text: string, configure?: Configure<QrSettings>): string[]`	Encode `text` and render it as terminal lines (see `QrSettings.compact`).
`render`	`render(text: string, configure?: Configure<QrSettings>): string`	Encode `text` and render it as one newline-joined string.
`print`	`print(text: string, configure?: Configure<QrSettings>, options?: QrPrintOptions): void`	Encode `text` and write each rendered line through `options.write` (default `console.log`).