1. A method of testing an electronic document page, the method comprising: causing a change to data accessible via a data model, the data model being usable to create an electronic document page, the page being defined by a page description implemented in a markup language, the page description referring to the data accessible via the data model; creating an intermediate representation of the page based on the page description and the data model, the intermediate representation including at least a portion of the data accessible via the data model that includes the changed data, the intermediate representation being renderable to create a rendered page, the rendered page being displayable on a display device; determining an expected value for a portion of the intermediate representation based on the change to the data accessible via the data model; identifying an actual value for the portion of the intermediate representation; determining whether the actual value matches the expected value; and when the actual value does not match the expected value, storing an indication of an error.