1 files changed, 146 insertions, 0 deletions
diff --git a/remote/test/puppeteer/packages/puppeteer-core/src/injected/TextContent.ts b/remote/test/puppeteer/packages/puppeteer-core/src/injected/TextContent.ts
new file mode 100644
index 0000000000..ffe8980d5e
--- /dev/null
+++ b/remote/test/puppeteer/packages/puppeteer-core/src/injected/TextContent.ts
@@ -0,0 +1,146 @@
+/**
+ * @license
+ * Copyright 2022 Google Inc.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+interface NonTrivialValueNode extends Node {
+  value: string;
+}
+
+const TRIVIAL_VALUE_INPUT_TYPES = new Set(['checkbox', 'image', 'radio']);
+
+/**
+ * Determines if the node has a non-trivial value property.
+ *
+ * @internal
+ */
+const isNonTrivialValueNode = (node: Node): node is NonTrivialValueNode => {
+  if (node instanceof HTMLSelectElement) {
+    return true;
+  }
+  if (node instanceof HTMLTextAreaElement) {
+    return true;
+  }
+  if (
+    node instanceof HTMLInputElement &&
+    !TRIVIAL_VALUE_INPUT_TYPES.has(node.type)
+  ) {
+    return true;
+  }
+  return false;
+};
+
+const UNSUITABLE_NODE_NAMES = new Set(['SCRIPT', 'STYLE']);
+
+/**
+ * Determines whether a given node is suitable for text matching.
+ *
+ * @internal
+ */
+export const isSuitableNodeForTextMatching = (node: Node): boolean => {
+  return (
+    !UNSUITABLE_NODE_NAMES.has(node.nodeName) && !document.head?.contains(node)
+  );
+};
+
+/**
+ * @internal
+ */
+export interface TextContent {
+  // Contains the full text of the node.
+  full: string;
+  // Contains the text immediately beneath the node.
+  immediate: string[];
+}
+
+/**
+ * Maps {@link Node}s to their computed {@link 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.
+ *
+ * @remarks
+ * The primary reason this function exists is due to {@link ShadowRoot}s not having
+ * text content.
+ *
+ * @internal
+ */
+export const createTextContent = (root: Node): TextContent => {
+  let value = textContentCache.get(root);
+  if (value) {
+    return value;
+  }
+  value = {full: '', immediate: []};
+  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) {
+        value.full += child.nodeValue ?? '';
+        currentImmediate += child.nodeValue ?? '';
+        continue;
+      }
+      if (currentImmediate) {
+        value.immediate.push(currentImmediate);
+      }
+      currentImmediate = '';
+      if (child.nodeType === Node.ELEMENT_NODE) {
+        value.full += createTextContent(child).full;
+      }
+    }
+    if (currentImmediate) {
+      value.immediate.push(currentImmediate);
+    }
+    if (root instanceof Element && root.shadowRoot) {
+      value.full += createTextContent(root.shadowRoot).full;
+    }
+
+    if (!observedNodes.has(root)) {
+      textChangeObserver.observe(root, {
+        childList: true,
+        characterData: true,
+        subtree: true,
+      });
+      observedNodes.add(root);
+    }
+  }
+  textContentCache.set(root, value);
+  return value;
+};