MFTF + tests, which AI generates the best Magento tests?

Claude Code, by a clear margin. The reasons map directly to its strengths:

• MFTF (Magento Functional Test Framework): XML-heavy, needs precise selectors, must match the actual UI of the page. Claude Code reads the layout XML, the phtml templates, and the existing MFTF tests, produces selectors that actually work. Cursor often misses the layout chain; Copilot guesses selectors and fails ~50% of the time.
• PHPUnit (unit + integration tests): Claude Code reads the existing test base classes, finds the right fixture pattern, generates tests that follow project conventions. Cursor does well in workspace; Copilot is hit-or-miss on Magento-specific patterns.
• Cypress / Playwright (E2E): all three are competent here, these frameworks have lots of training data. Pick whichever your team prefers.

Common Magento testing workflow with Claude Code:

1. “Read this controller and generate a PHPUnit test that covers the happy path + 2 error cases.”
2. “Now generate the MFTF test for the storefront flow.”
3. “Run them, fix any failures.”

15 minutes per controller, instead of 1-2 hours by hand. This is where the metered API cost pays for itself fast.