Writing CodeceptJS 4 Tests

A test that was never executed during authoring is unreliable. Drive the real browser via the CodeceptJS MCP server, verify every locator against the live page, commit only steps that passed.

Two modes, picked by how much of the flow you already know:

• Mode A — incremental run_code: send one or two I.* lines per call, read response, repeat. For extending existing tests, known flows, porting manual plans.
• Mode B — scaffold-and-pause (recommended for greenfield / unknown flows): write a stub Scenario containing I.amOnPage('/...'); pause();, run via MCP run_test. The browser opens and yields control at pause() — drive the live page via run_code, then replace pause() with the verified sequence.

Both share the same discovery / locator / commit steps; the difference is where the in-flight exploration happens.

Workflow