Mollie PHP client: revoking a mandate fails with Non-existent query parameter testmode

Calling the mandate revoke method in mollie-api-php 2.12.1 failed with Non-existent query parameter "testmode" for this API call. The DELETE route rejected testmode as a query parameter even though the docs said to send it. A maintainer confirmed it was a bug in the revoke method: the parameter was appended to the URL instead of being handled for the DELETE request. The maintainer's suggested workaround was to use $customer->revokeMandate($mandate->id) instead, which the reporter confirmed worked. Mollie then fixed it on their side by accepting testmode on those URLs.

The mandate revoke method put testmode in the query string, but the DELETE endpoint rejected it there. Fix: call $customer->revokeMandate($mandate->id) instead of the mandate resource's revoke method. This was the maintainer's suggested workaround and the reporter confirmed it worked. Mollie later fixed the API to accept testmode on these URLs, so newer API behavior handles it too. Source: https://github.com/mollie/mollie-api-php/issues/437

Source: https://github.com/mollie/mollie-api-php/issues/437