Third-party plugins

List of third-party plugins for grappa.

Official plugins

  • http - HTTP protocol assertions with domain-specific DSL.
  • server - Server/system assertions with domain-specific DSL.

Community plugins

Did you create your own plugin? Open an issue or send a Pull Request!

Creating your own plugin

Creating operators

from grappa import Operator

class MyEqualOperator(Operator):
    MyOperator implements a custom `grappa` assertion operator.

    Operators should inherit from `grappa.Operator` for convenience
    and implement `match()` method.

    # List of operators keywords (required)
    operators = ('equal', 'same', 'eql')

    # Chain DSL aliases (optional)
    aliases = ('to', 'of', 'type', 'as')

    # Expected custom message template (optional)
    expected_message = Operator.Dsl.Message(
        'expected a value that of type "{type}" that is equal to "{value}"',
        'expected a a value that is not equal to "{value}"',

    def match(self, subject, expected, **kw):
        return subject == expected, ['subject is not equal to {}'.format(expected)]

Alternatively, you can create and self-register simple, small operators via decorator:

import grappa

def my_accessor_operator(ctx, subject, **kw):
  return len(subject) > 3, ['subject length must be higher than 3']
import grappa

def my_matcher_operator(ctx, subject, expected, **kw):
  return subject == expected, ['values are not equal']

Registering the plugin

import grappa

# Explicitly register operators
def my_plugin_register(engine):
    engine.register(MyEqualOperator, MyOtherOperator)


Alternatively, you can self-register your operator classes via register decorator:

import grappa

class MyCustomOeprator(grappa.Operator)