behave-kit

The Swiss-army knife for Behave — soft assertions, typed context, conditional skip, environment management, fixtures and more.

Why behave-kit?

Behave is great for BDD, but real test suites need more than Given/When/Then. You need to:

• Collect multiple assertion failures without stopping at the first one
• Skip steps based on environment, OS, or missing dependencies
• Read environment variables with type conversion and validation
• Load test data from CSV, JSON, YAML, or Excel files
• Manage fixtures with automatic setup/teardown by tag
• Get IDE autocompletion for context attributes
• Debug failures with automatic context dumps
• Poll for conditions with configurable timeout and interval
• Assert expected exceptions as part of soft assertion collections
• Run data-driven steps from CSV, JSON, YAML, or Excel files
• Isolate environment variables with snapshot/restore context managers
• Navigate nested dicts with dot notation
• Assert execution time with assert_under and @timed
• Create temp directories for filesystem-isolated tests
• Continue after failed steps for comprehensive test reporting
• Execute sub-steps with outline substitution and state isolation
• Class-based steps — define Given/When/Then as methods on a class with self.context, lifecycle hooks, and per-step matchers
• Per-scenario timeout — @timeout:N tags override a default, platform-aware (SIGALRM on Unix, threading.Timer on Windows)

behave-kit provides all of these as independent, opt-in utilities — no monkey-patching, no breaking changes.

Installation

pip install behave-kit

With optional extras:

pip install "behave-kit[yaml,excel,dotenv]"

Quickstart

Level 1 — Automatic wiring

Add two lines to your environment.py and every feature is wired automatically:

from behave_kit import setup, teardown


def before_all(context):
    setup(context, env="staging")


def after_scenario(context, scenario):
    teardown(context)

Level 2 — Cherry-pick

Import only what you need:

from behave_kit import assert_soft, env, load_data


@then("the response should be valid")
def step(context):
    assert_soft(context.response.status_code == 200)
    api_key = env("API_KEY", required=True)
    users = load_data("tests/data/users.csv")

Level 3 — Namespace

import behave_kit as bk


@then("the response should be valid")
def step(context):
    bk.assert_soft(context.response.status_code == 200)

Features

Soft assertions

Collect multiple failures and report them all at once:

from behave_kit import assert_soft

assert_soft(response.status_code == 200)
assert_soft(response.body["count"] > 0)
assert_soft("error" not in response.body)
# All failures reported together at teardown

TypedContext

Schema-validated proxy with IDE autocompletion and mypy support:

from behave_kit import TypedContext


class MySchema:
    driver: str
    base_url: str


ctx = TypedContext(context, MySchema)
ctx.setup(driver="chrome", base_url="https://test.com")
print(ctx.driver)  # IDE autocompletion works

Conditional skip

Skip steps by environment, OS, or missing dependency:

from behave_kit import skip_if_env, skip_if_no_browser, skip_on_os, skip_if_missing


@skip_if_env("production")
@when("I run the staging-only step")
def step(context): ...


@skip_if_no_browser
@when("I open the browser")
def step(context): ...


@skip_on_os("windows")
@when("I run the unix-only step")
def step(context): ...


@skip_if_missing("selenium")
@when("I use selenium")
def step(context): ...

Environment variables

Typed reads with defaults, validation, and config file fallback:

from behave_kit import env

api_key = env("API_KEY", required=True)  # str
timeout = env("TIMEOUT", var_type=int, default=30)  # int
debug = env("DEBUG", var_type=bool, default=False)  # bool

Data loading

Single API for CSV, JSON, YAML, and Excel:

from behave_kit import load_data

users = load_data("tests/data/users.csv")  # list[dict]
config = load_data("tests/data/config.json")  # dict
sheet = load_data("tests/data/sheet.xlsx")  # list[dict] (requires [excel])

Fixtures

Tag-based setup/teardown with dependency resolution:

from behave_kit import fixture


@fixture("browser")
def browser_fixture(context):
    def setup(ctx):
        ctx.browser = start_browser()

    def teardown(ctx):
        ctx.browser.quit()

    return (setup, teardown)


@fixture("database", requires="browser")
def database_fixture(context): ...

Context dump

Automatic context snapshot on scenario failure for easier debugging:

from behave_kit import dump_context_on_failure
# Wired automatically by setup(), or call manually

Step suggestions

"Did you mean?" hints for undefined steps:

from behave_kit import setup_suggestions
# Wired automatically by setup()

Scoped attributes

Automatic cleanup of context attributes per scenario:

from behave_kit import scoped


@scoped("driver")
@when("I start the driver")
def step(context):
    context.driver = start_driver()


# "driver" is automatically deleted after the scenario

Conditional steps

Run a step only when a condition holds:

from behave_kit import when_if


@when_if(lambda ctx: ctx.config.env == "staging")
@when("I run the staging-only step")
def step(context): ...

Parameter types

Register custom Behave parameter types:

from behave_kit import parameter_type


@parameter_type("User", r"[\w.]+@[\w.]+\.[a-z]+")
def parse_user(text):
    return User(name=text)

Class-based steps

Define step implementations as methods on a class, with per-scenario instances, lifecycle hooks, and per-step matcher selection:

from behave_kit import step_impl_base

Base = step_impl_base()


class AccountSteps(Base):
    @Base.given("I have a balance of {amount:d}")
    def set_balance(self, amount):
        self.balance = amount

    @Base.when("I deposit {amount:d}")
    def deposit(self, amount):
        self.balance += amount

    @Base.then("the balance should be {expected:d}")
    def check_balance(self, expected):
        assert self.balance == expected

    @property
    def balance(self):
        return getattr(self.context, "balance", 0)

    @balance.setter
    def balance(self, value):
        self.context.balance = value

    def setup(self):
        # Called once when the instance is created for a scenario
        pass

    def teardown(self):
        # Called after the scenario ends (via teardown_steps / teardown)
        pass


AccountSteps.register()

self.context is bound automatically — no context parameter needed. Subclass to extend or override steps; register only the most-derived class. Pass matcher=RegexMatcher to a decorator for per-step matcher selection.

Soft exception assertions

Check that a callable raises an expected exception, collected as a soft failure:

from behave_kit import assert_soft_raises

assert_soft_raises(ValueError, lambda: int("abc"))
assert_soft_raises(KeyError, lambda: {}["missing"])
# Failures are collected and reported together at teardown

Data-driven steps

Run a step once per row of a data file, with column names injected as keyword arguments:

from behave_kit import data_driven


@data_driven("tests/data/users.csv")
@when("I login as {username}")
def step(context, username=None, password=None):
    login(username, password)


# Runs once per row in users.csv

Environment variable snapshot

Save and restore os.environ so tests don't leak environment variable changes:

from behave_kit import env_snapshot

with env_snapshot():
    os.environ["API_KEY"] = "test"
    # ... test ...
# API_KEY restored automatically

Dict navigation with get_path

Extract values from nested dicts using dot notation:

from behave_kit import get_path

city = get_path(response, "user.address.city")  # "Berlin"
name = get_path(response, "users.0.name", default="?")  # "Alice"

Time assertions

Assert that a callable completes within a time limit:

from behave_kit import assert_under, timed

assert_under(2.0, lambda: client.get("/health"))


@timed(1.5)
@when("I fetch the data")
def step(context): ...

Wait until

Poll a condition until it becomes true or a timeout is reached:

from behave_kit import wait_until

wait_until(lambda: context.response.status_code == 200, timeout=10, interval=0.5)

Temp workspace

Create an isolated temporary directory and restore the CWD on exit:

from behave_kit import temp_workspace

with temp_workspace() as tmp:
    config_path = tmp / "config.json"
    config_path.write_text("{}")
# Directory is cleaned up automatically

Continue after failed step

Control whether scenarios keep running remaining steps after a failure:

from behave_kit import continue_after_failed, continue_on_failure

# Enable globally
continue_after_failed(True)

# Or temporarily via context manager
with continue_on_failure():
    # scenarios inside this block continue after failed steps
    ...

Or wire it through setup():

from behave_kit import setup


def before_all(context):
    setup(context, continue_after_failed=True)

Sub-step execution with isolation

Execute Gherkin sub-steps with Scenario Outline variable substitution and guaranteed table/text restoration:

from behave_kit import run_steps


@when("I complete the checkout flow")
def step_impl(context):
    run_steps(
        context,
        """
        Given I have items in my cart
        When I enter shipping info for "<city>"
        Then I should see the order confirmation
    """,
    )


# context.table and context.text are preserved after execution

Per-scenario timeout

Set a default timeout and override it per scenario or feature with @timeout:N tags:

from behave_kit import setup_timeout
from behave_kit.timeout import timeout_before_scenario, timeout_after_scenario


def before_all(context):
    setup_timeout(context, default_timeout=30)


def before_scenario(context, scenario):
    timeout_before_scenario(context, scenario)


def after_scenario(context, scenario):
    timeout_after_scenario(context, scenario)

@timeout:10
Scenario: Fast scenario with tag override
  When I do something quick

@timeout:0
Scenario: Disable timeout for this scenario
  When I do something slow

@timeout:60
Feature: Feature-level timeout inherits to all scenarios

• Unix: uses signal.SIGALRM for immediate interruption.
• Windows: uses threading.Timer fallback (detected after step finishes).
• @timeout:0 disables the timeout for that scenario.
• Feature-level tags inherit to all scenarios; scenario tags override feature tags.

Documentation

Full documentation is available at mathiaspaulenko.github.io/behave-kit.

To build docs locally:

pip install "behave-kit[docs]"
cd docs && sphinx-build -b html . _build/html

Development

See CONTRIBUTING.md for development setup, coding standards, and contribution guidelines.

License

MIT — see LICENSE.