Initial commit

index.js

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+(function(root, factory) {
+  if (typeof define === 'function' && define.amd) {
+    define([], factory);
+  } else if (typeof exports === 'object') {
+    module.exports = factory();
+  } else {
+    root.invariant = factory();
+  }
+}(this, function() {
+  const scanForProblems = function (context, logError) {
+    for (const img of context.querySelectorAll('img')) {
+      if (!img.hasAttribute('alt')) {
+        logError(new ImageWithoutAltAttributeError(img))
+      }
+    }
+
+    for (const a of context.querySelectorAll('a')) {
+      if (a.hasAttribute('name') || elementIsHidden(a)) {
+        continue
+      }
+      if (a.getAttribute('href') == null && a.getAttribute('role') !== 'button') {
+        logError(new LinkWithoutLabelOrRoleError(a))
+      } else if (!accessibleText(a)) {
+        logError(new ElementWithoutLabelError(a))
+      }
+    }
+
+    for (const button of context.querySelectorAll('button')) {
+      if (!elementIsHidden(button) && !accessibleText(button)) {
+        logError(new ButtonWithoutLabelError(button))
+      }
+    }
+
+    for (const label of context.querySelectorAll('label')) {
+      // In case label.control isn't supported by browser, find the control manually (IE)
+      const control = label.control || document.getElementById(label.getAttribute('for')) || label.querySelector('input')
+
+      if (!control) {
+        logError(new LabelMissingControl(label), false)
+      }
+    }
+
+    for (const input of context.querySelectorAll('input[type=text], textarea')) {
+      if (input.labels && !input.labels.length && !elementIsHidden(input) && !input.hasAttribute('aria-label')) {
+        logError(new ElementWithoutLabelError(input))
+      }
+    }
+
+    for (const selector of Object.keys(SelectorARIAPairs)) {
+      const ARIAAttrsRequired = SelectorARIAPairs[selector]
+      for (const target of context.querySelectorAll(selector)) {
+        const missingAttrs = []
+        for (const attr of ARIAAttrsRequired) {
+          if (!target.hasAttribute(attr)) missingAttrs.push(attr)
+        }
+
+        if (missingAttrs.length > 0) {
+          logError(new ARIAAttributeMissingError(target, missingAttrs.join(', ')))
+        }
+      }
+    }
+  }
+
+  return scanForProblems
+}));
+
+function errorSubclass(fn) {
+  fn.prototype = new Error()
+  fn.prototype.constructor = fn
+}
+
+function ImageWithoutAltAttributeError(element) {
+  this.name = 'ImageWithoutAltAttributeError'
+  this.stack = new Error().stack
+  this.element = element
+  this.message = `Missing alt attribute on ${element.outerHTML}`
+}
+errorSubclass(ImageWithoutAltAttributeError)
+
+function ElementWithoutLabelError(element) {
+  this.name = 'ElementWithoutLabelError'
+  this.stack = new Error().stack
+  this.element = element
+  this.message = `Missing text, title, or aria-label attribute on ${element.outerHTML}`
+}
+errorSubclass(ElementWithoutLabelError)
+
+function LinkWithoutLabelOrRoleError(element) {
+  this.name = 'LinkWithoutLabelOrRoleError'
+  this.stack = new Error().stack
+  this.element = element
+  this.message = `Missing href or role=button on ${element.outerHTML}`
+}
+errorSubclass(LinkWithoutLabelOrRoleError)
+
+function LabelMissingControl(element) {
+  this.name = 'LabelMissingControl'
+  this.stack = new Error().stack
+  this.element = element
+  this.message = `Label missing control on ${element.outerHTML}`
+}
+errorSubclass(LabelMissingControl)
+
+function ButtonWithoutLabelError(element) {
+  this.name = 'ButtonWithoutLabelError'
+  this.stack = new Error().stack
+  this.element = element
+  this.message = `Missing text or aria-label attribute on ${element.outerHTML}`
+}
+errorSubclass(ButtonWithoutLabelError)
+
+function ARIAAttributeMissingError(element, attr) {
+  this.name = 'ARIAAttributeMissingError'
+  this.stack = new Error().stack
+  this.element = element
+  this.message = `Missing ${attr} attribute on ${element.outerHTML}`
+}
+errorSubclass(ARIAAttributeMissingError)
+
+const SelectorARIAPairs = {
+  ".js-menu-target": ["aria-expanded", "aria-haspopup"],
+  ".js-details-target": ["aria-expanded"]
+}
+
+function elementIsHidden(element) {
+  return element.getAttribute('aria-hidden') === 'true' || element.closest('[aria-hidden="true"]')
+}
+
+function isText(value) {
+  return typeof value === 'string' && !!value.trim()
+}
+
+// Public: Check if an element has text visible by sight or screen reader.
+//
+// Examples
+//
+//   <img alt="github" src="github.png">
+//   # => true
+//
+//   <span aria-label="Open"></span>
+//   # => true
+//
+//   <button></button>
+//   # => false
+//
+// Returns String text.
+function accessibleText(node) {
+  switch (node.nodeType) {
+    case Node.ELEMENT_NODE:
+      if (isText(node.getAttribute('alt')) || isText(node.getAttribute('aria-label')) || isText(node.getAttribute('title'))) return true
+      for (const child of node.childNodes) {
+        if (accessibleText(child)) return true
+      }
+      break
+    case Node.TEXT_NODE:
+      return isText(node.data)
+  }
+}

package.json

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+{
+  "name": "accessibilityjs",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/github/accessibilityjs.git"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/github/accessibilityjs/issues"
+  },
+  "homepage": "https://github.com/github/accessibilityjs#readme"
+}