DOM TreeWalker polyfill

JavaScript implementation of W3 DOM4 TreeWalker interface for browsers supporting ECMAScript 3 or higher.

Specification

TreeWalker:

• https://dom.spec.whatwg.org/#interface-treewalker
• http://www.w3.org/TR/dom/#interface-treewalker
• http://www.w3.org/TR/DOM-Level-2-Traversal-Range/traversal.html#Traversal-TreeWalker

document.createTreeWalker:

• https://dom.spec.whatwg.org/#dom-document-createtreewalker
• http://www.w3.org/TR/dom/#dom-document-createtreewalker
• http://www.w3.org/TR/DOM-Level-2-Traversal-Range/traversal.html#NodeIteratorFactory-createTreeWalker

During the development of this polyfill, I noticed a [https://www.w3.org/Bugs/Public/show_bug.cgi?id=20445 defect] in the WHATWG DOM specification (patch 1, patch 2)). The finding is acknowledged at https://dom.spec.whatwg.org/#acks.

Tests

By default the tests run against the code in src/. Any native TreeWalker implementation is disabled as part of the test set up.

• To test the native implementation, run UNIT_USE_NATIVE=true npm test.
• To test the minified version, run UNIT_USE_MIN=true npm test.
• Both, run UNIT_USE_MIN=true UNIT_USE_NATIVE=true npm test.
• To debug tests in your browser (instead of Headless), use npm run karma-debug. Then press the "Debug" button in the browser window to start the tests.