chore: incrementally erase cache on text change (#8961)

src/common/QueryHandler.ts

@@ -276,55 +276,12 @@ const xpathHandler = createPuppeteerQueryHandler({
 });
 
 const textQueryHandler = createPuppeteerQueryHandler({
-  queryOne: (element, selector, {createTextContent}) => {
-    const search = (root: Node): Node | null => {
-      for (const node of root.childNodes) {
-        if (node instanceof Element) {
-          let matchedNode: Node | null;
-          if (node.shadowRoot) {
-            matchedNode = search(node.shadowRoot);
-          } else {
-            matchedNode = search(node);
-          }
-          if (matchedNode) {
-            return matchedNode;
-          }
-        }
-      }
-      const textContent = createTextContent(root);
-      if (textContent.full.includes(selector)) {
-        return root;
-      }
-      return null;
-    };
-    return search(element);
+  queryOne: (element, selector, {textQuerySelector}) => {
+    return textQuerySelector(selector, element);
   },
 
-  queryAll: (element, selector, {createTextContent}) => {
-    const search = (root: Node): Node[] => {
-      let results: Node[] = [];
-      for (const node of root.childNodes) {
-        if (node instanceof Element) {
-          let matchedNodes: Node[];
-          if (node.shadowRoot) {
-            matchedNodes = search(node.shadowRoot);
-          } else {
-            matchedNodes = search(node);
-          }
-          results = results.concat(matchedNodes);
-        }
-      }
-      if (results.length > 0) {
-        return results;
-      }
-
-      const textContent = createTextContent(root);
-      if (textContent.full.includes(selector)) {
-        return [root];
-      }
-      return [];
-    };
-    return search(element);
+  queryAll: (element, selector, {textQuerySelectorAll}) => {
+    return textQuerySelectorAll(selector, element);
   },
 });
 

src/injected/CSSSelector.ts

@@ -0,0 +1,198 @@
+import {SelectorPart} from './PathPart.js';
+
+const getCSSNodeName = (node: Node): string => {
+  // If node is not an element, it's case sensitive
+  if (!(node instanceof Element)) {
+    return node.nodeName;
+  }
+
+  // If the names are different lengths, there is a prefix and it's case sensitive
+  if (node.localName.length !== node.nodeName.length) {
+    return node.nodeName;
+  }
+
+  // Return the local name, which will be case insensitive if its an html node
+  return node.localName;
+};
+
+const getPrefixedClassNames = (node: Element): Set<string> => {
+  const classAttribute = node.getAttribute('class');
+  if (!classAttribute) {
+    return new Set();
+  }
+
+  return new Set(
+    classAttribute
+      .split(/\s+/g)
+      .filter(Boolean)
+      .map(name => {
+        // The prefix is required to store "__proto__" in a object-based map.
+        return `$${name}`;
+      })
+  );
+};
+
+const idSelector = (id: string): string => {
+  return `#${CSS.escape(id)}`;
+};
+
+const attributeSelector = (name: string, value: string): string => {
+  return `[${name}=${CSS.escape(value)}]`;
+};
+
+const getSelectorPart = (
+  node: Node,
+  optimized: boolean,
+  isTargetNode: boolean,
+  attributes: string[] = []
+): SelectorPart | undefined => {
+  if (!(node instanceof Element)) {
+    return;
+  }
+
+  const id = node.id;
+  if (optimized) {
+    for (const attribute of attributes) {
+      const value = node.getAttribute(attribute);
+      if (value) {
+        return new SelectorPart(attributeSelector(attribute, value), true);
+      }
+    }
+    if (id) {
+      return new SelectorPart(idSelector(id), true);
+    }
+    switch (node.nodeName) {
+      case 'BODY':
+      case 'HEAD':
+      case 'HTML':
+        return new SelectorPart(getCSSNodeName(node), true);
+    }
+  }
+  const nodeName = getCSSNodeName(node);
+
+  if (id) {
+    return new SelectorPart(`${nodeName}${idSelector(id)}`, true);
+  }
+  const parent = node.parentNode;
+  if (!parent) {
+    return new SelectorPart(nodeName, true);
+  }
+
+  const classNames = getPrefixedClassNames(node);
+  let needsClassNames = false;
+  let needsNthChild = false;
+  let nodeIndex = -1;
+  const children = parent.children;
+
+  // If there are no class names, we will use the `nth-child` selector.
+  if (!classNames.size) {
+    needsNthChild = true;
+  }
+
+  for (
+    let i = 0;
+    (nodeIndex < 0 || !needsNthChild) && i < children.length;
+    ++i
+  ) {
+    const child = children[i]!;
+    if (child === node) {
+      nodeIndex = i;
+      continue;
+    }
+    if (needsNthChild) {
+      continue;
+    }
+    if (getCSSNodeName(child) !== nodeName) {
+      continue;
+    }
+
+    // Remove class names that are from children to keep things unique.
+    needsClassNames = true;
+    for (const childClassName of getPrefixedClassNames(child)) {
+      if (!classNames.has(childClassName)) {
+        continue;
+      }
+      classNames.delete(childClassName);
+      // If we run out of unique class names, we circle back to the `nth-child` selector.
+      if (!classNames.size) {
+        needsNthChild = true;
+        break;
+      }
+    }
+  }
+
+  let selector = nodeName;
+  if (
+    isTargetNode &&
+    nodeName.toLowerCase() === 'input' &&
+    node.getAttribute('type') &&
+    !node.getAttribute('id') &&
+    !node.getAttribute('class')
+  ) {
+    selector += '[type=' + CSS.escape(node.getAttribute('type') || '') + ']';
+  }
+
+  if (needsNthChild) {
+    selector += ':nth-child(' + (nodeIndex + 1) + ')';
+  } else if (needsClassNames) {
+    for (const prefixedName of classNames) {
+      selector += '.' + CSS.escape(prefixedName.slice(1));
+    }
+  }
+
+  return new SelectorPart(selector, false);
+};
+
+/**
+ * Computes the CSS selector for a node.
+ *
+ * @param node - The node to compute.
+ * @param optimized - Whether to optimize the CSS selector for the node. Does
+ * not imply the selector is shorter; implies the selector will be highly-scoped
+ * to the node.
+ * @returns The computed CSS selector.
+ *
+ * @internal
+ */
+export const computeCSSSelector = (
+  node: Node | null,
+  optimized?: boolean,
+  attributes?: string[]
+): {root: Node | null; selector: string} => {
+  const parts = [];
+  let contextNode: Node | null = node;
+  while (contextNode) {
+    const part = getSelectorPart(
+      contextNode,
+      !!optimized,
+      contextNode === node,
+      attributes
+    );
+    if (!part) {
+      break;
+    } // Error - bail out early.
+    parts.push(part);
+    if (part.optimized) {
+      break;
+    }
+    contextNode = contextNode.parentNode;
+  }
+
+  parts.reverse();
+
+  contextNode = node;
+  while (contextNode) {
+    if (contextNode instanceof ShadowRoot) {
+      return {
+        selector: parts.join(' > '),
+        root: contextNode,
+      };
+    }
+    contextNode = contextNode.parentNode;
+  }
+
+  return {
+    selector: parts.join(' > '),
+    root: null,
+  };
+};

src/injected/PathPart.ts

@@ -0,0 +1,15 @@
+/**
+ * @internal
+ */
+export class SelectorPart {
+  value: string;
+  optimized: boolean;
+  constructor(value: string, optimized: boolean) {
+    this.value = value;
+    this.optimized = optimized || false;
+  }
+
+  toString(): string {
+    return this.value;
+  }
+}

src/injected/Poller.ts

@@ -37,7 +37,6 @@ export class MutationPoller<T> implements Poller<T> {
     }
 
     this.#observer = new MutationObserver(async () => {
-      console.log(1);
       const result = await this.#fn();
       if (!result) {
         return;

src/injected/TextContent.ts

@@ -27,8 +27,10 @@ const UNSUITABLE_NODE_NAMES = new Set(['SCRIPT', 'STYLE']);
 
 /**
  * Determines whether a given node is suitable for text matching.
+ *
+ * @internal
  */
-const isSuitableNodeForTextMatching = (node: Node): boolean => {
+export const isSuitableNodeForTextMatching = (node: Node): boolean => {
   return (
     !UNSUITABLE_NODE_NAMES.has(node.nodeName) && !document.head?.contains(node)
   );
@@ -47,7 +49,27 @@ export type TextContent = {
 /**
  * Maps {@link Node}s to their computed {@link TextContent}.
  */
-const textContentCache = new Map<Node, TextContent>();
+const textContentCache = new WeakMap<Node, TextContent>();
+const eraseFromCache = (node: Node | null) => {
+  while (node) {
+    textContentCache.delete(node);
+    if (node instanceof ShadowRoot) {
+      node = node.host;
+    } else {
+      node = node.parentNode;
+    }
+  }
+};
+
+/**
+ * Erases the cache when the tree has mutated text.
+ */
+const observedNodes = new WeakSet<Node>();
+const textChangeObserver = new MutationObserver(mutations => {
+  for (const mutation of mutations) {
+    eraseFromCache(mutation.target);
+  }
+});
 
 /**
  * Builds the text content of a node using some custom logic.
@@ -67,10 +89,19 @@ export const createTextContent = (root: Node): TextContent => {
   if (!isSuitableNodeForTextMatching(root)) {
     return value;
   }
+
   let currentImmediate = '';
   if (isNonTrivialValueNode(root)) {
     value.full = root.value;
     value.immediate.push(root.value);
+
+    root.addEventListener(
+      'input',
+      event => {
+        eraseFromCache(event.target as HTMLInputElement);
+      },
+      {once: true, capture: true}
+    );
   } else {
     for (let child = root.firstChild; child; child = child.nextSibling) {
       if (child.nodeType === Node.TEXT_NODE) {
@@ -92,6 +123,14 @@ export const createTextContent = (root: Node): TextContent => {
     if (root instanceof Element && root.shadowRoot) {
       value.full += createTextContent(root.shadowRoot).full;
     }
+
+    if (!observedNodes.has(root)) {
+      textChangeObserver.observe(root, {
+        childList: true,
+        characterData: true,
+      });
+      observedNodes.add(root);
+    }
   }
   textContentCache.set(root, value);
   return value;

src/injected/TextSelector.ts

@@ -0,0 +1,98 @@
+import {
+  createTextContent,
+  isSuitableNodeForTextMatching,
+} from './TextContent.js';
+
+/**
+ * Queries the given node for a node matching the given text selector.
+ *
+ * @internal
+ */
+export const textQuerySelector = (
+  selector: string,
+  root: Node
+): Element | null => {
+  for (const node of root.childNodes) {
+    if (node instanceof Element && isSuitableNodeForTextMatching(node)) {
+      let matchedNode: Element | null;
+      if (node.shadowRoot) {
+        matchedNode = textQuerySelector(selector, node.shadowRoot);
+      } else {
+        matchedNode = textQuerySelector(selector, node);
+      }
+      if (matchedNode) {
+        return matchedNode;
+      }
+    }
+  }
+
+  if (root instanceof Element) {
+    const textContent = createTextContent(root);
+    if (textContent.full.includes(selector)) {
+      return root;
+    }
+  }
+  return null;
+};
+
+/**
+ * Queries the given node for all nodes matching the given text selector.
+ *
+ * @internal
+ */
+export const textQuerySelectorAll = (
+  selector: string,
+  root: Node
+): Element[] => {
+  let results: Element[] = [];
+  for (const node of root.childNodes) {
+    if (node instanceof Element) {
+      let matchedNodes: Element[];
+      if (node.shadowRoot) {
+        matchedNodes = textQuerySelectorAll(selector, node.shadowRoot);
+      } else {
+        matchedNodes = textQuerySelectorAll(selector, node);
+      }
+      results = results.concat(matchedNodes);
+    }
+  }
+  if (results.length > 0) {
+    return results;
+  }
+
+  if (root instanceof Element) {
+    const textContent = createTextContent(root);
+    if (textContent.full.includes(selector)) {
+      return [root];
+    }
+  }
+  return [];
+};
+
+/**
+ * Computes the text selector for a node.
+ *
+ * @param node - The node to compute.
+ * @returns The computed text selector.
+ *
+ * @internal
+ */
+export const computeTextSelector = (node: Node): string => {
+  const content = createTextContent(node).full;
+
+  // We do a binary search for the optimal length.
+  let i = 0;
+  let j = content.length;
+  while (i <= j) {
+    const k = i + ((j - i) >> 2);
+    // Centering the slice.
+    const left = (content.length - k) >> 2;
+    const right = k + left;
+    if (textQuerySelector(content.slice(left, right), document) !== node) {
+      i = k + 1;
+    } else {
+      j = k - 1;
+    }
+  }
+  return content.slice(0, i);
+};

src/injected/XPath.ts

@@ -0,0 +1,128 @@
+import {assert} from '../util/assert.js';
+import {SelectorPart} from './PathPart.js';
+
+const getSelectorPart = (node: Node, optimized?: boolean): SelectorPart => {
+  let value;
+  switch (node.nodeType) {
+    case Node.ELEMENT_NODE:
+      assert(node instanceof Element);
+      if (optimized && node.getAttribute('id')) {
+        return new SelectorPart(`//*[@id="${node.getAttribute('id')}"]`, true);
+      }
+      value = node.localName;
+      break;
+    case Node.ATTRIBUTE_NODE:
+      value = '@' + node.nodeName;
+      break;
+    case Node.TEXT_NODE:
+    case Node.CDATA_SECTION_NODE:
+      value = 'text()';
+      break;
+    case Node.PROCESSING_INSTRUCTION_NODE:
+      value = 'processing-instruction()';
+      break;
+    case Node.COMMENT_NODE:
+      value = 'comment()';
+      break;
+    case Node.DOCUMENT_NODE:
+      value = '';
+      break;
+    default:
+      value = '';
+      break;
+  }
+
+  const index = getXPathIndexInParent(node);
+  if (index > 0) {
+    value += `[${index}]`;
+  }
+
+  return new SelectorPart(value, node.nodeType === Node.DOCUMENT_NODE);
+};
+
+const getXPathIndexInParent = (node: Node): number => {
+  /**
+   * @returns -1 in case of error, 0 if no siblings matching the same expression,
+   * XPath index among the same expression-matching sibling nodes otherwise.
+   */
+  function areNodesSimilar(left: Node, right: Node): boolean {
+    if (left === right) {
+      return true;
+    }
+
+    if (left instanceof Element && right instanceof Element) {
+      return left.localName === right.localName;
+    }
+
+    if (left.nodeType === right.nodeType) {
+      return true;
+    }
+
+    // XPath treats CDATA as text nodes.
+    const leftType =
+      left.nodeType === Node.CDATA_SECTION_NODE
+        ? Node.TEXT_NODE
+        : left.nodeType;
+    const rightType =
+      right.nodeType === Node.CDATA_SECTION_NODE
+        ? Node.TEXT_NODE
+        : right.nodeType;
+    return leftType === rightType;
+  }
+
+  const children = node.parentNode ? node.parentNode.children : null;
+  if (!children) {
+    return 0;
+  }
+  let hasSameNamedElements;
+  for (let i = 0; i < children.length; ++i) {
+    if (areNodesSimilar(node, children[i]!) && children[i] !== node) {
+      hasSameNamedElements = true;
+      break;
+    }
+  }
+  if (!hasSameNamedElements) {
+    return 0;
+  }
+  let ownIndex = 1; // XPath indices start with 1.
+  for (let i = 0; i < children.length; ++i) {
+    if (areNodesSimilar(node, children[i]!)) {
+      if (children[i] === node) {
+        return ownIndex;
+      }
+      ++ownIndex;
+    }
+  }
+
+  assert(false, 'This is impossible; a child must be the child of the parent');
+};
+
+/**
+ * Computes the XPath for a node.
+ *
+ * @param node - The node to compute.
+ * @param optimized - Whether to optimize the XPath for the node. Does not imply
+ * the XPath is shorter; implies the XPath will be highly-scoped to the node.
+ * @returns The computed XPath.
+ *
+ * @internal
+ */
+export const computeXPath = (node: Node, optimized?: boolean): string => {
+  if (node.nodeType === Node.DOCUMENT_NODE) {
+    return '/';
+  }
+
+  const parts = [];
+  let contextNode: Node | null = node;
+  while (contextNode) {
+    const part = getSelectorPart(contextNode, optimized);
+    parts.push(part);
+    if (part.optimized) {
+      break;
+    }
+    contextNode = contextNode.parentNode;
+  }
+
+  parts.reverse();
+  return (parts.length && parts[0]!.optimized ? '' : '/') + parts.join('/');
+};

src/injected/injected.ts

@@ -2,11 +2,13 @@ import {createDeferredPromise} from '../util/DeferredPromise.js';
 import * as util from './util.js';
 import * as Poller from './Poller.js';
 import * as TextContent from './TextContent.js';
+import * as TextSelector from './TextSelector.js';
 
 const PuppeteerUtil = Object.freeze({
   ...util,
   ...Poller,
   ...TextContent,
+  ...TextSelector,
   createDeferredPromise,
 });
 

test/src/computeselectors.spec.ts

@@ -0,0 +1,61 @@
+/**
+ * Copyright 2022 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 expect from 'expect';
+import {MAIN_WORLD} from '../../lib/cjs/puppeteer/common/IsolatedWorld.js';
+import {
+  getTestState,
+  setupTestBrowserHooks,
+  setupTestPageAndContextHooks,
+} from './mocha-utils.js';
+
+describe('Selector computation tests', function () {
+  setupTestBrowserHooks();
+  setupTestPageAndContextHooks();
+
+  describe('for text selectors', () => {
+    it('should compute text selectors correctly.', async () => {
+      const {page} = getTestState();
+
+      // Each element is a list of `a`s. Since `computeTextSelector` performs
+      // binary search only on the front slice, the selector should be the
+      // smallest number of `a`s that that make the selector unique.
+      await page.setContent(
+        `<div>${'a'.repeat(7)}</div><div>${'a'.repeat(
+          9
+        )}</div><div id="to-be-computed">${'a'.repeat(5)}<div>${'a'.repeat(
+          10
+        )}</div>${'a'.repeat(4)}</div>`
+      );
+
+      const selector = await page.evaluate(({computeTextSelector}) => {
+        return computeTextSelector(document.getElementById('to-be-computed')!);
+      }, await page.mainFrame().worlds[MAIN_WORLD].puppeteerUtil);
+
+      // Since to-be-computed has the most amount of `a`s, it just needs to have
+      // one more than every other element which computes to 11.
+      expect(selector).toBe('a'.repeat(11));
+
+      // Make sure the inverse operation works!
+      const element = await page.$(`text/${selector}`);
+      await expect(
+        element?.evaluate(e => {
+          return e.id;
+        })
+      ).resolves.toBe('to-be-computed');
+    });
+  });
+});

test/src/queryhandler.spec.ts

@@ -197,6 +197,73 @@ describe('Query handler tests', function () {
           })
         ).toBe('a b');
       });
+      it('should clear caches', async () => {
+        const {page} = getTestState();
+
+        await page.setContent(
+          '<div id=target1>text</div><input id=target2 value=text><div id=target3>text</div>'
+        );
+        const div = (await page.$('#target1')) as ElementHandle<HTMLDivElement>;
+        const input = (await page.$(
+          '#target2'
+        )) as ElementHandle<HTMLInputElement>;
+
+        await div.evaluate(div => {
+          div.textContent = 'text';
+        });
+        expect(
+          await page.$eval(`text/text`, e => {
+            return e.id;
+          })
+        ).toBe('target1');
+        await div.evaluate(div => {
+          div.textContent = 'foo';
+        });
+        expect(
+          await page.$eval(`text/text`, e => {
+            return e.id;
+          })
+        ).toBe('target2');
+        await input.evaluate(input => {
+          input.value = '';
+        });
+        await input.type('foo');
+        expect(
+          await page.$eval(`text/text`, e => {
+            return e.id;
+          })
+        ).toBe('target3');
+
+        await div.evaluate(div => {
+          div.textContent = 'text';
+        });
+        await input.evaluate(input => {
+          input.value = '';
+        });
+        await input.type('text');
+        expect(
+          await page.$$eval(`text/text`, es => {
+            return es.length;
+          })
+        ).toBe(3);
+        await div.evaluate(div => {
+          div.textContent = 'foo';
+        });
+        expect(
+          await page.$$eval(`text/text`, es => {
+            return es.length;
+          })
+        ).toBe(2);
+        await input.evaluate(input => {
+          input.value = '';
+        });
+        await input.type('foo');
+        expect(
+          await page.$$eval(`text/text`, es => {
+            return es.length;
+          })
+        ).toBe(1);
+      });
     });
     describe('in ElementHandles', function () {
       it('should query existing element', async () => {

utils/generate_sources.ts

@@ -36,7 +36,7 @@ const INCLUDED_FOLDERS = ['common', 'node', 'generated', 'util', 'api'];
       outdir: tmp,
       format: 'cjs',
       platform: 'browser',
-      target: 'ES2019',
+      target: 'ES2022',
     });
     const baseName = path.basename(input);
     const content = await readFile(