puppeteer/packages/puppeteer-core/src/common/AriaQueryHandler.ts
2023-02-15 15:09:31 -08:00

125 lines
4.0 KiB
TypeScript

/**
* Copyright 2020 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import {Protocol} from 'devtools-protocol';
import {ElementHandle} from '../api/ElementHandle.js';
import {assert} from '../util/assert.js';
import {AsyncIterableUtil} from '../util/AsyncIterableUtil.js';
import {CDPSession} from './Connection.js';
import {QueryHandler, QuerySelector} from './QueryHandler.js';
import {AwaitableIterable} from './types.js';
const queryAXTree = async (
client: CDPSession,
element: ElementHandle<Node>,
accessibleName?: string,
role?: string
): Promise<Protocol.Accessibility.AXNode[]> => {
const {nodes} = await client.send('Accessibility.queryAXTree', {
objectId: element.id,
accessibleName,
role,
});
return nodes.filter((node: Protocol.Accessibility.AXNode) => {
return !node.role || node.role.value !== 'StaticText';
});
};
type ARIASelector = {name?: string; role?: string};
const KNOWN_ATTRIBUTES = Object.freeze(['name', 'role']);
const isKnownAttribute = (
attribute: string
): attribute is keyof ARIASelector => {
return KNOWN_ATTRIBUTES.includes(attribute);
};
const normalizeValue = (value: string): string => {
return value.replace(/ +/g, ' ').trim();
};
/**
* The selectors consist of an accessible name to query for and optionally
* further aria attributes on the form `[<attribute>=<value>]`.
* Currently, we only support the `name` and `role` attribute.
* The following examples showcase how the syntax works wrt. querying:
*
* - 'title[role="heading"]' queries for elements with name 'title' and role 'heading'.
* - '[role="img"]' queries for elements with role 'img' and any name.
* - 'label' queries for elements with name 'label' and any role.
* - '[name=""][role="button"]' queries for elements with no name and role 'button'.
*/
const ATTRIBUTE_REGEXP =
/\[\s*(?<attribute>\w+)\s*=\s*(?<quote>"|')(?<value>\\.|.*?(?=\k<quote>))\k<quote>\s*\]/g;
const parseARIASelector = (selector: string): ARIASelector => {
const queryOptions: ARIASelector = {};
const defaultName = selector.replace(
ATTRIBUTE_REGEXP,
(_, attribute, __, value) => {
attribute = attribute.trim();
assert(
isKnownAttribute(attribute),
`Unknown aria attribute "${attribute}" in selector`
);
queryOptions[attribute] = normalizeValue(value);
return '';
}
);
if (defaultName && !queryOptions.name) {
queryOptions.name = normalizeValue(defaultName);
}
return queryOptions;
};
/**
* @internal
*/
export class ARIAQueryHandler extends QueryHandler {
static override querySelector: QuerySelector = async (
node,
selector,
{ariaQuerySelector}
) => {
return ariaQuerySelector(node, selector);
};
static override async *queryAll(
element: ElementHandle<Node>,
selector: string
): AwaitableIterable<ElementHandle<Node>> {
const context = element.executionContext();
const {name, role} = parseARIASelector(selector);
const results = await queryAXTree(context._client, element, name, role);
const world = context._world!;
yield* AsyncIterableUtil.map(results, node => {
return world.adoptBackendNode(node.backendDOMNodeId) as Promise<
ElementHandle<Node>
>;
});
}
static override queryOne = async (
element: ElementHandle<Node>,
selector: string
): Promise<ElementHandle<Node> | null> => {
return (
(await AsyncIterableUtil.first(this.queryAll(element, selector))) ?? null
);
};
}