Add Schemathesis

src/content/code/tools/schemathesis.md

@@ -0,0 +1,37 @@
+---
+name: Schemathesis
+description: A modern API testing tool for web applications built with Open API and GraphQL specifications.
+url: https://github.com/schemathesis/schemathesis
+github: schemathesis/schemathesis
+---
+
+Install Schemathesis via `pip`:
+
+```bash
+pip install schemathesis
+```
+
+Then, create a file `test_api.py` with the content below and replace the `URL` value with your own GraphQL endpoint URL:
+
+```python
+from hypothesis import settings
+import schemathesis
+
+URL = "https://your.app.com/graphql"
+schema = schemathesis.graphql.from_url(URL)
+
+@schema.parametrize()
+@settings(deadline=None)
+def test_api(case):
+    response = case.call()
+    case.validate_response(response)
+```
+
+Then run `pytest test_api.py`. Note that you can write your app in any programming language; the tool will communicate with it over HTTP.
+
+Schemathesis will generate valid queries automatically based on the schema and will minimize failing cases.
+For example, running the code above against `https://bahnql.herokuapp.com/graphql` uncovers that running the `{ search(searchTerm: "") { stations { name } } }` query leads to a server error:
+
+```
+{"errors":[{"message":"Cannot read property \'city\' of undefined","locations":[{"line":1,"column":28}],"path":["search","stations"]}],"data":null}
+```