Autocomplete
// Definition
A UI pattern that suggests completions as the user types, typically backed by a search or lookup endpoint. Testing concerns include: suggestions appearing for partial input, debouncing (requests should not fire on every keystroke), keyboard navigation through suggestions, screen-reader accessibility, and what happens when the backend is slow or returns no results. Also verify that selecting a suggestion correctly populates the target field and that the suggestion list closes on blur or Escape.
// Related terms
Full-Text Search
A search mechanism that matches query terms against the full content of indexed documents, not just field-level equality. Testing concerns include: relevance ranking (are the most relevant results first?), partial-word and stemming behaviour, special-character handling, empty query results, very long queries, and search across multiple fields. Also verify performance under load — full-text search is computationally heavier than simple filtering — and that results are consistent when the same search is repeated.
DOM
The Document Object Model — a tree-shaped, in-memory representation of an HTML (or XML) document that the browser builds after parsing the page source. Each element becomes a node, and JavaScript (and test tools like Playwright and Selenium) interact with the page by traversing and manipulating this tree. Understanding the DOM is essential for writing stable locators: a query like `#submit-btn` targets the DOM node, not the raw HTML string.