Add support for disabled checkboxes, task-list-items

These changes add support for allowing only certain values for a property and
to define required attributes.

Closes GH-12.
Closes GH-13.

Reviewed-by: Christian Murphy <christian.murphy.42@gmail.com>

Co-authored-by: Arystan <ari7even@gmail.com>

lib/github.json

@@ -100,7 +100,8 @@
     "s",
     "strike",
     "summary",
-    "details"
+    "details",
+    "input"
   ],
   "attributes": {
     "a": [
@@ -110,6 +111,13 @@
       "src",
       "longDesc"
     ],
+    "input": [
+      ["type", "checkbox"],
+      ["disabled", true]
+    ],
+    "li": [
+      ["className", "task-list-item"]
+    ],
     "div": [
       "itemScope",
       "itemType"
@@ -196,5 +204,11 @@
       "width",
       "itemProp"
     ]
+  },
+  "required": {
+    "input": {
+      "type": "checkbox",
+      "disabled": true
+    }
   }
 }

lib/index.js

@@ -7,6 +7,8 @@ module.exports = wrapper
 
 var own = {}.hasOwnProperty
 
+var allData = 'data*'
+
 var NODES = {
   root: {children: all},
   doctype: handleDoctype,
@@ -134,48 +136,62 @@ function all(schema, children, node, stack) {
 function handleProperties(schema, properties, node, stack) {
   var name = handleTagName(schema, node.tagName, node, stack)
   var attrs = schema.attributes
+  var reqs = schema.required || /* istanbul ignore next */ {}
   var props = properties || {}
   var result = {}
   var allowed
+  var required
+  var definition
   var prop
   var value
 
-  allowed = own.call(attrs, name) ? attrs[name] : []
-  allowed = [].concat(allowed, attrs['*'])
+  allowed = xtend(
+    toPropertyValueMap(attrs['*']),
+    toPropertyValueMap(own.call(attrs, name) ? attrs[name] : [])
+  )
 
   for (prop in props) {
     value = props[prop]
 
-    if (
-      allowed.indexOf(prop) === -1 &&
-      !(data(prop) && allowed.indexOf('data*') !== -1)
-    ) {
+    if (own.call(allowed, prop)) {
+      definition = allowed[prop]
+    } else if (data(prop) && own.call(allowed, allData)) {
+      definition = allowed[allData]
+    } else {
       continue
     }
 
     if (value && typeof value === 'object' && 'length' in value) {
-      value = handlePropertyValues(schema, value, prop)
+      value = handlePropertyValues(schema, value, prop, definition)
     } else {
-      value = handlePropertyValue(schema, value, prop)
+      value = handlePropertyValue(schema, value, prop, definition)
     }
 
     if (value !== null && value !== undefined) {
       result[prop] = value
     }
   }
 
+  required = own.call(reqs, name) ? reqs[name] : {}
+
+  for (prop in required) {
+    if (!own.call(result, prop)) {
+      result[prop] = required[prop]
+    }
+  }
+
   return result
 }
 
 // Sanitize a property value which is a list.
-function handlePropertyValues(schema, values, prop) {
+function handlePropertyValues(schema, values, prop, definition) {
   var length = values.length
   var result = []
   var index = -1
   var value
 
   while (++index < length) {
-    value = handlePropertyValue(schema, values[index], prop)
+    value = handlePropertyValue(schema, values[index], prop, definition)
 
     if (value !== null && value !== undefined) {
       result.push(value)
@@ -186,7 +202,7 @@ function handlePropertyValues(schema, values, prop) {
 }
 
 // Sanitize a property value.
-function handlePropertyValue(schema, value, prop) {
+function handlePropertyValue(schema, value, prop, definition) {
   if (
     typeof value !== 'boolean' &&
     typeof value !== 'number' &&
@@ -199,6 +215,10 @@ function handlePropertyValue(schema, value, prop) {
     return null
   }
 
+  if (definition.length !== 0 && definition.indexOf(value) === -1) {
+    return null
+  }
+
   if (schema.clobber.indexOf(prop) !== -1) {
     value = schema.clobberPrefix + value
   }
@@ -314,6 +334,26 @@ function handleValue(schema, value) {
   return typeof value === 'string' ? value : ''
 }
 
+// Create a map from a list of props or a list of properties and values.
+function toPropertyValueMap(values) {
+  var result = {}
+  var length = values.length
+  var index = -1
+  var value
+
+  while (++index < length) {
+    value = values[index]
+
+    if (value && typeof value === 'object' && 'length' in value) {
+      result[value[0]] = value.slice(1)
+    } else {
+      result[value] = []
+    }
+  }
+
+  return result
+}
+
 // Allow `value`.
 function allow(schema, value) {
   return value

readme.md

@@ -136,6 +136,44 @@ properties.
 }
 ```
 
+Instead of a single string (such as `type`), which allows any value of that
+attribute, it’s also possible to provide an array (such as `['type',
+'checkbox']`), where the first entry is the key, and the other entries are
+allowed values of that property.
+
+This is how the default GitHub schema allows only disabled checkbox inputs:
+
+```js
+"attributes": {
+  // ...
+  "input": [
+    ["type", "checkbox"],
+    ["disabled", true]
+  ],
+  // ...
+}
+```
+
+###### `required`
+
+Map of tag-names to required attributes and their default values
+(`Object.<Object.<*>>`).
+If the properties in such a required attributes object do not exist on an
+element, they are added and set to the specified value.
+
+Note that properties are first checked based on the schema at `attributes`,
+so properties could be removed by that step and then added again through
+`required`.
+
+```js
+"required": {
+  "input": {
+    "type": "checkbox",
+    "disabled": true
+  }
+}
+```
+
 ###### `tagNames`
 
 List of allowed tag-names (`Array.<string>`).

test.js

@@ -487,6 +487,110 @@ test('sanitize()', function(t) {
       })
     })
 
+    st.deepEqual(
+      sanitize(h('input')),
+      h('input', {type: 'checkbox', disabled: true}),
+      'should allow only disabled checkbox inputs'
+    )
+
+    st.deepEqual(
+      sanitize(h('input', {type: 'text'})),
+      h('input', {type: 'checkbox', disabled: true}),
+      'should not allow text inputs'
+    )
+
+    st.deepEqual(
+      sanitize(h('input', {type: 'checkbox', disabled: false})),
+      h('input', {type: 'checkbox', disabled: true}),
+      'should not allow enabled inputs'
+    )
+
+    st.deepEqual(
+      sanitize(h('ol', [h('li')])),
+      h('ol', [h('li')]),
+      'should allow list items'
+    )
+
+    st.deepEqual(
+      sanitize(h('ol', [h('li', {className: ['foo', 'bar']})])),
+      h('ol', [h('li', {className: []})]),
+      'should not allow classes on list items'
+    )
+
+    st.deepEqual(
+      sanitize(h('ol', [h('li', {className: ['foo', 'task-list-item']})])),
+      h('ol', [h('li', {className: ['task-list-item']})]),
+      'should only allow `task-list-item` as a class on list items'
+    )
+
+    st.deepEqual(
+      sanitize(h('select')),
+      u('root', []),
+      'should ignore some elements by default'
+    )
+
+    st.deepEqual(
+      sanitize(h('select'), merge(gh, {tagNames: ['select']})),
+      h('select'),
+      'should support allowing elements through the schema'
+    )
+
+    st.deepEqual(
+      sanitize(
+        h('select', {autoComplete: true}),
+        merge(gh, {tagNames: ['select']})
+      ),
+      h('select'),
+      'should ignore attributes for new elements'
+    )
+
+    st.deepEqual(
+      sanitize(
+        h('select', {autoComplete: true}),
+        merge(gh, {
+          tagNames: ['select'],
+          attributes: {select: ['autoComplete']}
+        })
+      ),
+      h('select', {autoComplete: true}),
+      'should support allowing attributes for new elements through the schema'
+    )
+
+    st.deepEqual(
+      sanitize(
+        h('div', [h('select', {form: 'one'}), h('select', {form: 'two'})]),
+        merge(gh, {
+          tagNames: ['select'],
+          attributes: {select: [['form', 'one']]}
+        })
+      ),
+      h('div', [h('select', {form: 'one'}), h('select')]),
+      'should support a list of valid values on new attributes'
+    )
+
+    st.deepEqual(
+      sanitize(
+        h('div', [
+          h('select', {form: 'alpha'}),
+          h('select', {form: 'bravo'}),
+          h('select', {}),
+          h('select', {form: false})
+        ]),
+        merge(gh, {
+          tagNames: ['select'],
+          attributes: {select: [['form', 'alpha']]},
+          required: {select: {form: 'alpha'}}
+        })
+      ),
+      h('div', [
+        h('select', {form: 'alpha'}),
+        h('select', {form: 'alpha'}),
+        h('select', {form: 'alpha'}),
+        h('select', {form: 'alpha'})
+      ]),
+      'should support required attributes'
+    )
+
     st.end()
   })