// Package axe carries the vendored axe-core engine and runs it in a
// page a browser drive is already on. The engine is test data: it is
// pinned and checksummed in README.md beside it, read by the
// accessibility drives, and never part of anything the root package
// ships.
//
// Run, the half that needs a browser, is build-tagged `browser`, as
// the harness is, so chromedp stays out of the plain build graph.
package axe

import (
	_ "embed"
)

// script is axe.min.js, embedded so Run can hand it to the page as
// data. Only this package embeds it: the root package's tree is css/,
// js/, icons/ and LICENSE, and TestVendoredAxeIsThePinnedVersion
// holds the file to the README's pin.
//
//go:embed axe.min.js
var script string

// Script returns the engine's source, for a drive that injects it
// into a document of its own (a preview frame, say) rather than the
// page Run scans.
func Script() string { return script }

// defaultTags is the ruleset Scan uses when handed no tags, and it is
// not negotiable downwards. WCAG 2.2 AA is cumulative: 2.2 AA means
// every A and AA criterion from 2.0, 2.1 and 2.2, so all five tags
// have to be named or the older half of the standard silently stops
// being checked.
//
// Deliberately absent: best-practice, experimental and ACT tags. They
// are useful advice and they are not the standard the question asked
// about; mixing them in would make a failure mean two different
// things.
var defaultTags = []string{"wcag2a", "wcag2aa", "wcag21a", "wcag21aa", "wcag22aa"}

// DefaultTags returns the ruleset Scan uses when handed no tags, as a
// copy: a caller that appends to or reslices what it gets changes
// nothing a later scan reads.
func DefaultTags() []string { return append([]string(nil), defaultTags...) }

// Violation is one rule that found something: its id, axe's impact
// word, the one-line help text, and a selector for every node it
// found, so a failure names itself.
type Violation struct {
	ID     string
	Impact string
	Help   string
	Nodes  []string
}