Types

Every export is typed in its .d.ts; this is the shape of the ones most likely to be written out.

Renderable

type Renderable =
  | string
  | number
  | bigint
  | boolean
  | null
  | undefined
  | Html
  | Iterable<Renderable>
  | (() => Renderable);

What a template accepts, and therefore the type to give a slot. Objects and promises are absent deliberately, so ${user} is a type error rather than [object Object], and an un-awaited promise fails to compile rather than rendering as nothing.

From @itsy/html.

AttrValue

type AttrValue =
  | string | number | bigint | boolean | null | undefined
  | ClassValue[] // class
  | StyleValue // style
  | AttrGroup; // aria, data

A value for attrs(). true gives a bare attribute, false and nullish leave it out — except for aria-*, draggable, spellcheck and contenteditable, where booleans render "true" and "false".

ClassValue

type ClassValue =
  | string | number | bigint | boolean | null | undefined
  | ClassValue[]
  | Record<string, unknown>;

What cx() takes, and what the class key in attrs() takes. Arrays nest, objects contribute the keys whose value is truthy, and falsy values are skipped.

StyleValue

type StyleValue = Record<string, string | number | null | undefined | false>;

A style attribute as an object. Keys are written out exactly as given — --brand, background-color — with no camelCase conversion. null, undefined and false drop the declaration.

AttrGroup

type AttrGroup = Record<string, string | number | bigint | boolean | null | undefined>;

The object form of aria and data, so aria: { expanded: open } becomes aria-expanded="…".

Problem

interface Problem {
  code: number;
  message: string;
  at: number;
  near: string;
}

What check() returns, one per problem, in page order. at is a character offset; in a template a ${…} counts as those four characters. From @itsy/html/check, along with CheckOptions.

Finding

interface Finding<R extends string = string> {
  rule: R;
  message: string;
  at: number;
  near: string;
}

What a rule reports, mixed into the same list as Problem by check(). Names, not numbers: these are not HtmlError codes, and nothing here ever throws. Tell the two apart with 'rule' in p. From @itsy/html/check.

A11yRule is the union of the twenty-five names the built-in accessibility rules can report. check(markup) returns Finding<A11yRule>, so a comparison against a name that does not exist is a type error rather than a test that never matches, and a11y: { without: [...] } checks its entries the same way. That object is A11yOptions, also from @itsy/html/check.

RuleSet, Visitor, Report

type RuleSet = (report: Report) => Visitor;
type Report = (rule: string, message: string, at: number) => void;

interface Visitor {
  open?: (tag: string, attrs: ReadonlyMap<string, string>, at: number, ancestors: readonly string[]) => void;
  text?: (content: string, at: number, ancestors: readonly string[]) => void;
  close?: (tag: string, at: number, hadText: boolean) => void;
  end?: (ids: ReadonlyMap<string, number>) => void;
}

A project's own rules, for check()'s rules option. Every hook is optional. From @itsy/html/check.

Passing custom rules widens the result to Finding<string>, since this cannot know their names.

FrameOptions, HeadEntry, FramePart

From @itsy/html/frame; the fields are listed in the frame API. FramePart is HeadEntry | Html, which is what head and scripts accept.

CreateOptions

interface CreateOptions {
  schemes?: Iterable<string>;
  collapse?: boolean;
}

From @itsy/html/create.