feat(selectors): implement builtin selectors in new evaluator (#4579)

This commit is contained in:
Dmitry Gozman 2020-12-03 14:10:40 -08:00 committed by GitHub
parent 3121de403b
commit 016925cd16
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

View File

@ -17,8 +17,9 @@
import { CSSComplexSelector, CSSSimpleSelector, CSSComplexSelectorList, CSSFunctionArgument } from '../common/cssParser';
export type QueryContext = {
scope: Element | ShadowRoot | Document;
// Place for more options, e.g. normalizing whitespace or piercing shadow.
scope: Element | Document;
pierceShadow: boolean;
// Place for more options, e.g. normalizing whitespace.
};
export type Selector = any; // Opaque selector type.
export interface SelectorEvaluator {
@ -42,6 +43,11 @@ export class SelectorEvaluatorImpl implements SelectorEvaluator {
this._engines.set('where', isEngine);
this._engines.set('has', hasEngine);
this._engines.set('scope', scopeEngine);
this._engines.set('text', textEngine);
this._engines.set('matches-text', matchesTextEngine);
this._engines.set('xpath', xpathEngine);
for (const attr of ['id', 'data-testid', 'data-test-id', 'data-test'])
this._engines.set(attr, createAttributeEngine(attr));
// TODO: host
// TODO: host-context?
}
@ -154,19 +160,19 @@ export class SelectorEvaluatorImpl implements SelectorEvaluator {
return true;
const { selector: simple, combinator } = complex.simples[index];
if (combinator === '>') {
const parent = parentElementOrShadowHostInScope(element, context.scope);
const parent = parentElementOrShadowHostInContext(element, context);
if (!parent || !this._matchesSimple(parent, simple, context))
return false;
return this._matchesParents(parent, complex, index - 1, context);
}
if (combinator === '+') {
const previousSibling = element === context.scope ? null : element.previousElementSibling;
const previousSibling = previousSiblingInContext(element, context);
if (!previousSibling || !this._matchesSimple(previousSibling, simple, context))
return false;
return this._matchesParents(previousSibling, complex, index - 1, context);
}
if (combinator === '') {
let parent = parentElementOrShadowHostInScope(element, context.scope);
let parent = parentElementOrShadowHostInContext(element, context);
while (parent) {
if (this._matchesSimple(parent, simple, context)) {
if (this._matchesParents(parent, complex, index - 1, context))
@ -174,12 +180,12 @@ export class SelectorEvaluatorImpl implements SelectorEvaluator {
if (complex.simples[index - 1].combinator === '')
break;
}
parent = parentElementOrShadowHostInScope(parent, context.scope);
parent = parentElementOrShadowHostInContext(parent, context);
}
return false;
}
if (combinator === '~') {
let previousSibling = element === context.scope ? null : element.previousElementSibling;
let previousSibling = previousSiblingInContext(element, context);
while (previousSibling) {
if (this._matchesSimple(previousSibling, simple, context)) {
if (this._matchesParents(previousSibling, complex, index - 1, context))
@ -187,7 +193,7 @@ export class SelectorEvaluatorImpl implements SelectorEvaluator {
if (complex.simples[index - 1].combinator === '~')
break;
}
previousSibling = previousSibling === context.scope ? null : previousSibling.previousElementSibling;
previousSibling = previousSiblingInContext(previousSibling, context);
}
return false;
}
@ -212,13 +218,13 @@ export class SelectorEvaluatorImpl implements SelectorEvaluator {
}
private _callMatches(engine: SelectorEngine, element: Element, args: CSSFunctionArgument[], context: QueryContext): boolean {
return this._cached<boolean>(element, ['_callMatches', engine, args, context.scope], () => {
return this._cached<boolean>(element, ['_callMatches', engine, args, context.scope, context.pierceShadow], () => {
return engine.matches!(element, args, context, this);
});
}
private _callQuery(engine: SelectorEngine, args: CSSFunctionArgument[], context: QueryContext): Element[] {
return this._cached<Element[]>(args, ['_callQuery', engine, context.scope], () => {
return this._cached<Element[]>(args, ['_callQuery', engine, context.scope, context.pierceShadow], () => {
return engine.query!(context, args, this);
});
}
@ -229,11 +235,13 @@ export class SelectorEvaluatorImpl implements SelectorEvaluator {
});
}
private _queryCSS(context: QueryContext, css: string): Element[] {
_queryCSS(context: QueryContext, css: string): Element[] {
return this._cached<Element[]>(css, ['_queryCSS', context], () => {
const result: Element[] = [];
function query(root: Element | ShadowRoot | Document) {
result.push(...root.querySelectorAll(css));
if (!context.pierceShadow)
return;
if ((root as Element).shadowRoot)
query((root as Element).shadowRoot!);
for (const element of root.querySelectorAll('*')) {
@ -255,13 +263,13 @@ export class SelectorEvaluatorImpl implements SelectorEvaluator {
}
const isEngine: SelectorEngine = {
matches(element: Element, args: any[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
matches(element: Element, args: (string | number | Selector)[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
if (args.length === 0)
throw new Error(`"is" engine expects non-empty selector list`);
return args.some(selector => evaluator.matches(element, selector, context));
},
query(context: QueryContext, args: any[], evaluator: SelectorEvaluator): Element[] {
query(context: QueryContext, args: (string | number | Selector)[], evaluator: SelectorEvaluator): Element[] {
if (args.length === 0)
throw new Error(`"is" engine expects non-empty selector list`);
const elements: Element[] = [];
@ -273,7 +281,7 @@ const isEngine: SelectorEngine = {
};
const hasEngine: SelectorEngine = {
matches(element: Element, args: any[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
matches(element: Element, args: (string | number | Selector)[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
if (args.length === 0)
throw new Error(`"has" engine expects non-empty selector list`);
return evaluator.query({ ...context, scope: element }, args).length > 0;
@ -284,7 +292,7 @@ const hasEngine: SelectorEngine = {
};
const scopeEngine: SelectorEngine = {
matches(element: Element, args: any[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
matches(element: Element, args: (string | number | Selector)[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
if (args.length !== 0)
throw new Error(`"scope" engine expects no arguments`);
if (context.scope.nodeType === 9 /* Node.DOCUMENT_NODE */)
@ -292,7 +300,7 @@ const scopeEngine: SelectorEngine = {
return element === context.scope;
},
query(context: QueryContext, args: any[], evaluator: SelectorEvaluator): Element[] {
query(context: QueryContext, args: (string | number | Selector)[], evaluator: SelectorEvaluator): Element[] {
if (args.length !== 0)
throw new Error(`"scope" engine expects no arguments`);
if (context.scope.nodeType === 9 /* Node.DOCUMENT_NODE */) {
@ -306,13 +314,102 @@ const scopeEngine: SelectorEngine = {
};
const notEngine: SelectorEngine = {
matches(element: Element, args: any[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
matches(element: Element, args: (string | number | Selector)[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
if (args.length === 0)
throw new Error(`"not" engine expects non-empty selector list`);
return !evaluator.matches(element, args, context);
},
};
const textEngine: SelectorEngine = {
matches(element: Element, args: (string | number | Selector)[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
if (args.length === 0 || typeof args[0] !== 'string' || args.length > 2 || (args.length === 2 && typeof args[1] !== 'string'))
throw new Error(`"text" engine expects a string and an optional flags string`);
const text = args[0];
const flags = args.length === 2 ? args[1] : '';
const matcher = textMatcher(text, flags);
return elementMatchesText(element, context, matcher);
},
};
const matchesTextEngine: SelectorEngine = {
matches(element: Element, args: (string | number | Selector)[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
if (args.length === 0 || typeof args[0] !== 'string' || args.length > 2 || (args.length === 2 && typeof args[1] !== 'string'))
throw new Error(`"matches-text" engine expects a regexp body and optional regexp flags`);
const re = new RegExp(args[0], args.length === 2 ? args[1] : undefined);
return elementMatchesText(element, context, s => re.test(s));
},
};
function textMatcher(text: string, flags: string): (s: string) => boolean {
const normalizeSpace = flags.includes('s');
const lowerCase = flags.includes('i');
const substring = flags.includes('g');
if (normalizeSpace)
text = text.trim().replace(/\s+/g, ' ');
if (lowerCase)
text = text.toLowerCase();
return (s: string) => {
if (normalizeSpace)
s = s.trim().replace(/\s+/g, ' ');
if (lowerCase)
s = s.toLowerCase();
return substring ? s.includes(text) : s === text;
};
}
function elementMatchesText(element: Element, context: QueryContext, matcher: (s: string) => boolean) {
if (element.nodeName === 'SCRIPT' || element.nodeName === 'STYLE' || document.head && document.head.contains(element))
return false;
if ((element instanceof HTMLInputElement) && (element.type === 'submit' || element.type === 'button') && matcher(element.value))
return true;
let lastText = '';
for (let child = element.firstChild; child; child = child.nextSibling) {
if (child.nodeType === 3 /* Node.TEXT_NODE */) {
lastText += child.nodeValue;
} else {
if (lastText && matcher(lastText))
return true;
lastText = '';
}
}
return !!lastText && matcher(lastText);
}
const xpathEngine: SelectorEngine = {
query(context: QueryContext, args: (string | number | Selector)[], evaluator: SelectorEvaluator): Element[] {
if (args.length !== 1 || typeof args[0] !== 'string')
throw new Error(`"xpath" engine expects a single string`);
const document = context.scope.nodeType === 9 /* Node.DOCUMENT_NODE */ ? context.scope as Document : context.scope.ownerDocument;
if (!document)
return [];
const result: Element[] = [];
const it = document.evaluate(args[0], context.scope, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE);
for (let node = it.iterateNext(); node; node = it.iterateNext()) {
if (node.nodeType === 1 /* Node.ELEMENT_NODE */)
result.push(node as Element);
}
return result;
},
};
function createAttributeEngine(attr: string): SelectorEngine {
return {
matches(element: Element, args: (string | number | Selector)[], context: QueryContext, evaluator: SelectorEvaluator): boolean {
if (args.length === 0 || typeof args[0] !== 'string')
throw new Error(`"${attr}" engine expects a single string`);
return element.getAttribute(attr) === args[0];
},
query(context: QueryContext, args: (string | number | Selector)[], evaluator: SelectorEvaluator): Element[] {
if (args.length !== 1 || typeof args[0] !== 'string')
throw new Error(`"${attr}" engine expects a single string`);
const css = `[${attr}=${CSS.escape(args[0])}]`;
return (evaluator as SelectorEvaluatorImpl)._queryCSS(context, css);
},
};
}
function parentElementOrShadowHost(element: Element): Element | undefined {
if (element.parentElement)
return element.parentElement;
@ -322,8 +419,18 @@ function parentElementOrShadowHost(element: Element): Element | undefined {
return (element.parentNode as ShadowRoot).host;
}
function parentElementOrShadowHostInScope(element: Element, scope: Element | ShadowRoot | Document): Element | undefined {
return element === scope ? undefined : parentElementOrShadowHost(element);
function parentElementOrShadowHostInContext(element: Element, context: QueryContext): Element | undefined {
if (element === context.scope)
return;
if (!context.pierceShadow)
return element.parentElement || undefined;
return parentElementOrShadowHost(element);
}
function previousSiblingInContext(element: Element, context: QueryContext): Element | undefined {
if (element === context.scope)
return;
return element.previousElementSibling || undefined;
}
function sortInDOMOrder(elements: Element[]): Element[] {