Storing network requests

For debugging purposes, it can be useful to store all requests generated by Schemathesis and all responses from the app into a separate file. Schemathesis allows you to do this with -store-network-log command-line option:

$ schemathesis run --store-network-log=cassette.yaml

This command will create a new YAML file that will network interactions in VCR format. It might look like this:

command: 'schemathesis run --store-network-log=cassette.yaml'
recorded_with: 'Schemathesis 1.2.0'
- id: '0'
  status: 'FAILURE'
  seed: '1'
  elapsed: '0.00123'
  recorded_at: '2020-04-22T17:52:51.275318'
    uri: ''
    method: 'GET'
      encoding: 'utf-8'
      base64_string: ''
      code: '500'
      message: 'Internal Server Error'
      encoding: 'utf-8'
      base64_string: 'NTAwOiBJbnRlcm5hbCBTZXJ2ZXIgRXJyb3I='
    http_version: '1.1'

Schemathesis provides the following extra fields:

  • command. Full CLI command used to run Schemathesis.
  • A numeric interaction ID within the current cassette.
  • http_interactions.status. Type of test outcome, is one of SUCCESS, FAILURE, ERROR.
  • http_interactions.seed. Hypothesis seed used in that particular case could be used as an argument to --hypothesis-seed CLI option to reproduce this request.
  • http_interactions.elapsed. Time in seconds that a request took.

To work with the cassette you could use yq or any similar tool. Show response body content of first failed interaction:

$ yq r foo.yaml 'http_interactions.(status==FAILURE).response.body.base64_string' | head -n 1 | base64 -d
500: Internal Server Error

Check payload in requests to /api/upload_file:

$ yq r foo.yaml 'http_interactions.(request.uri==' | base64 -d
Content-Disposition: form-data; name="data"; filename="data"


Replaying interactions

Saved cassettes can be replayed with schemathesis replay command. Additionally, you may filter what interactions to replay by these parameters:

  • id. Specific, unique ID;
  • status. Replay only interactions with this status (SUCCESS, FAILURE or ERROR);
  • uri. A regular expression for request URI;
  • method. A regular expression for request method;

During replaying Schemathesis will output interactions being replayed together with the response codes from the initial and current execution:

$ schemathesis replay foo.yaml --status=FAILURE
Replaying cassette: foo.yaml
Total interactions: 4005

  ID              : 0
  URI             :
  Old status code : 500
  New status code : 500

  ID              : 1
  URI             :
  Old status code : 500
  New status code : 500

Export CLI test results to JUnit.xml

It is possible to export test results to format, acceptable by such tools as Jenkins.

$ schemathesis run --junit-xml=/path/junit.xml

This command will create an XML at given path as in example below.

<?xml version="1.0" ?>
<testsuites disabled="0" errors="1" failures="1" tests="3" time="0.10743043999536894">
    <testsuite disabled="0" errors="1" failures="1" name="schemathesis" skipped="0" tests="3" time="0.10743043999536894" hostname="bespin">
        <testcase name="GET /api/failure" time="0.089057">
            <failure type="failure" message="2. Received a response with 5xx status code: 500"/>
        <testcase name="GET /api/malformed_json" time="0.011977">
            <error type="error" message="json.decoder.JSONDecodeError: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)
">Traceback (most recent call last):
  File &quot;/home/user/work/schemathesis/src/schemathesis/runner/impl/;, line 87, in run_test
    test(checks, targets, result, **kwargs)
  File &quot;/home/user/work/schemathesis/src/schemathesis/runner/impl/;, line 150, in network_test
    case: Case,
  File &quot;/home/user/.pyenv/versions/3.8.0/envs/schemathesis/lib/python3.8/site-packages/hypothesis/;, line 1095, in wrapped_test
    raise the_error_hypothesis_found
  File &quot;/home/user/work/schemathesis/src/schemathesis/runner/impl/;, line 165, in network_test
    run_checks(case, checks, result, response)
  File &quot;/home/user/work/schemathesis/src/schemathesis/runner/impl/;, line 133, in run_checks
    check(response, case)
  File &quot;/home/user/work/schemathesis/src/schemathesis/;, line 87, in response_schema_conformance
    data = response.json()
  File &quot;/home/user/.pyenv/versions/3.8.0/envs/schemathesis/lib/python3.8/site-packages/requests/;, line 889, in json
    return complexjson.loads(
  File &quot;/home/user/.pyenv/versions/3.8.0/lib/python3.8/json/;, line 357, in loads
    return _default_decoder.decode(s)
  File &quot;/home/user/.pyenv/versions/3.8.0/lib/python3.8/json/;, line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File &quot;/home/user/.pyenv/versions/3.8.0/lib/python3.8/json/;, line 353, in raw_decode
    obj, end = self.scan_once(s, idx)
json.decoder.JSONDecodeError: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)
        <testcase name="GET /api/success" time="0.006397"/>

Base URL configuration

If your Open API schema defines servers (or basePath in Open API 2.0), then these values will be used to construct full endpoint URL during testing. In case of Open API 3.0 the first value from servers will be used.

However, you may want to run tests against a different base URL. To do this you need to pass --base-url option in CLI or provide base_url argument to a loader / runner if you use Schemathesis in your code:

schemathesis run --base-url=

And if your schema defines servers like this

  - url:{basePath}
        default: v1

Then the tests will be executed against /api/v2 base path.