by voitta-ai
Capture the exact outbound request body a single-page app sends, and stop it before it reaches the server. Use when: (1) you need the real JSON payload of an action (export, purchase, submit) to compare against an expected fix, (2) triggering the action for real would cost money, credits, or create a record you cannot undo, (3) a fetch-only interceptor "did not fire" and the request went out anyway, (4) you must prove which of two endpoints an action actually posts to, (5) you are verifying a frontend fix by observing behaviour rather than reading the bundle, (6) the harness is installed but captures nothing on an Angular/zone.js app — prototype patches are bypassed and you need the constructor-level swap plus a pre-flight proof before any risky click, (7) you must prove a submission actually created something, not just that a request left the browser. Covers patching window.fetch AND XMLHttpRequest together (the XHR half is the one usually missed), the constructor swap for zone.js apps, the pre-flight gate, matcher scope (block the commit call, never the dialog's own reads), recording responses, blocking cleanly, and disarming afterwards — including why a hash-route navigation does not remove the patch.
Claude Code