beehave 0.3.0

A thin layer on Hypothesis for Gherkin-style BDD testing with vocabulary enforcement

Keep your living documentation and test code in sync — without the step-definition boilerplate.

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beehave is a simpler alternative to behave and pytest-bdd. Instead of writing step definitions that match Gherkin step text to Python functions with @given/@when/@then decorators, beehave links scenarios to tests by function name alone. It generates pure Hypothesis property-based test stubs from your .feature files and checks that your test code stays consistent with your spec. Your tests never import beehave — they just use hypothesis.

pip install beehave

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How it differs from standard Gherkin tools

Traditional BDD frameworks (behave, pytest-bdd) require step definitions — separate Python functions decorated with @given/@when/@then whose text must match the Gherkin step text exactly. This creates fragile coupling, boilerplate, and framework lock-in. beehave eliminates all of that:

• No step definitions. The function name is the link. Scenario: guard bee inspects visitor → test_guard_bee_inspects_visitor.
• No runtime imports. Your tests import only hypothesis. beehave is a dev-time CLI.
• Property-based by default. Hypothesis @given() strategies are inferred from Examples table types. behave and pytest-bdd are example-only.

To make this work, beehave applies a few constraints beyond standard Gherkin:

Constraint	Why
Titles contain only letters, digits, and spaces	They become Python identifiers (test_...) and file paths
<placeholder> names must be valid Python identifiers, not keywords or builtins	They become function parameters
"quoted strings" and bare numbers in step text are enforced literals	check verifies they appear as Constant nodes in the function body
Scenario titles are globally unique across all features	One function name = one scenario, everywhere

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Usage

Write a feature

# docs/features/hive_activity.feature
Feature: Hive Activity

  Background:
    Given the hive is active

  Scenario Outline: honey production from nectar
    Given the hive has <nectar> grams of nectar
    And the evaporation rate is <rate> percent
    When the bees fan their wings for <hours> hours
    Then the hive produces <honey> grams of honey

    Examples:
      | nectar | rate | hours | honey |
      | 100    | 20   | 8     | 80    |
      | 200    | 25   | 12    | 150   |
      | 50     | 30   | 6     | 35    |

  Rule: Hive defense

    Background:
      Given the entrance has 2 guards

    Scenario: guard bee inspects visitor
      Given a visitor bee with <scent> colony odor
      When the guard inspects the visitor for "floral" scent
      Then the visitor is <outcome>

  Rule: Foraging

    Scenario: forager returns with nectar
      Given a forager bee named <name>
      When the forager returns with <volume> milliliters of nectar
      Then the hive stores <volume> milliliters of nectar

Generate stubs

beehave generate hive_activity

tests/features/hive_activity/
├── default_test.py        # top-level scenarios (honey production outline)
├── hive_defense_test.py   # Rule: Hive defense (guard bee)
└── foraging_test.py       # Rule: Foraging (forager returns)

# tests/features/hive_activity/default_test.py
from hypothesis import given, example, strategies as st

@example(nectar=100, rate=20, hours=8, honey=80)
@example(nectar=200, rate=25, hours=12, honey=150)
@example(nectar=50, rate=30, hours=6, honey=35)
@given(nectar=st.integers(), rate=st.integers(), hours=st.integers(), honey=st.integers())
def test_honey_production_from_nectar(nectar, rate, hours, honey):
    ...

# tests/features/hive_activity/hive_defense_test.py
from hypothesis import given, strategies as st

@given(scent=st.text(), outcome=st.text())
def test_guard_bee_inspects_visitor(scent, outcome):
    ...

Note what beehave extracted automatically:

• <nectar>, <rate> … → @given() parameters. Strategies inferred from Examples table types (all integers → st.integers()).
• 100, 20 … → @example() rows from the Examples table.
• "floral" → enforced literal from step text. check verifies it appears in the function body.
• 2 (from Rule Background 2 guards) → enforced literal, inherited by all scenarios in that Rule.
• <scent>, <outcome> → @given() parameters. No Examples table, so strategy falls back to st.text().

Check consistency

You implement the guard test:

@given(scent=st.text(), outcome=st.text())
def test_guard_bee_inspects_visitor(scent, outcome):
    assert "floral" in known_scents()
    assert 2 == guard_count()
    assert scent in ("floral", "citrus")
    assert outcome in ("admitted", "rejected")

beehave check hive_activity    # check one feature
beehave check                  # check all features

Remove the "floral" assertion and check catches it:

tests/features/hive_activity/hive_defense_test.py:4: missing-literal: literal '"floral"' not found in function body

Remove <scent> from the body but keep it as a @given() parameter? Still caught — beehave checks the body only:

tests/features/hive_activity/hive_defense_test.py:4: missing-placeholder: 'scent' not found in function body

Rename the scenario? Both sides are reported:

docs/features/hive_activity.feature:22: unmapped-scenario: scenario 'guard checks visitor' has no test function
tests/features/hive_activity/hive_defense_test.py:4: unmapped-test: 'test_guard_bee_inspects_visitor' has no matching scenario

Clean up stale functions

beehave clean hive_activity           # remove unmapped stubs only (safe)
beehave clean hive_activity --force   # remove any unmapped function

List features

beehave list          # paths and titles
beehave list -v       # include scenario counts, rules, stub status

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What check enforces

Check	Severity	What it catches
unmapped-scenario	error	Scenario has no matching test function
unmapped-test	error	Test function has no matching scenario
missing-placeholder	error	<placeholder> not referenced in function body
missing-literal	error	"string" or numeric literal not in function body
example-mismatch	error	Examples row has no matching @example() or vice versa
misplaced-test	warning	Function in wrong file (e.g., after Rule removal)

Warnings exit 0. Errors exit 1. Stubs (bodies with only pass or ...) skip body enforcement until you implement them.

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How it maps

• Scenario title → function name: Honey Production From Nectar → test_honey_production_from_nectar. Globally unique across all features.
• Rule → test file: Top-level scenarios go to default_test.py. Scenarios inside a Rule go to <rule>_test.py.
• Feature title → directory: Hive Activity → tests/features/hive_activity/.
• Strategy inference: Examples table column values are typed — all integers → st.integers(), all floats → st.floats(), all booleans → st.booleans(), else → st.text().
• Background merging: Feature Background applies to all scenarios. Rule Background applies to that Rule's scenarios only. Background steps cannot contain <placeholders>.
• Literal extraction: "quoted strings" and numeric tokens in step text are enforced as Constant AST nodes in the function body.

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Configuration

# pyproject.toml
[tool.beehave]
features_dir = "docs/features"
tests_dir = "tests/features"
default_strategy = "text"
background_check_numeric = true
background_check_string = true

Option	Default	Description
features_dir	docs/features	Where .feature files live
tests_dir	tests/features	Where generated tests go
default_strategy	text	Fallback strategy for unknown placeholders
background_check_numeric	true	Enforce numeric literals from Background steps
background_check_string	true	Enforce string literals from Background steps

License

MIT