Heroku has many public API endpoints. Each of these endpoints needs to be tested so that we know how they work, and documented so that our customers (and other API consumers) know how they work. Follow along, and we’ll learn how Heroku uses JSON Schema to test and document our Platform API – and how it helped us uncover an unexpected bug, rooted in the way the Oj gem parses Big Decimals.
JSON Schema files are like blueprints that define the structure and semantics of other JSON documents. When a JSON Schema file is applied to a JSON document, you can determine whether the document is valid (conforms to the schema) or is invalid (does not conform to the schema).
So how do we at Heroku use...