Skip to content

Latest commit

 

History

History

README.md

Cucumber logo
Cucumber Tag Expressions

Readable boolean expressions to select features and scenarios marked with tags in Gherkin

npm build backers sponsors build

# -- SIMPLE TAG-EXPRESSION EXAMPLES:
@a and @b
@a or @b
not @a

# -- MORE TAG-EXPRESSION EXAMPLES:
@a and not @b
(@a or @b) and not @c

Getting Started

Cucumber Tag Expressions is available as cucumber-tag-expressions on PyPI.

pip install cucumber-tag-expressions

Parse tag expressions and evaluate them against a set of tags.

>>> from cucumber_tag_expressions import parse

# Tagged with @fast
>>> fast = parse("@fast")
>>> fast({"@fast", "@wip"})
True
>>> fast({"@performance", "@slow"})
False

# Tagged with @wip and not @slow
>>> wip_not_slow = parse("@wip and not @slow")
>>> wip_not_slow({"@wip", "@home"})
True
>>> wip_not_slow({"wet", "warm", "raining"})
False

# Tagged with both `@fast` and `@integration`
>>> fast_integration = parse("@integration and @fast")
>>> fast_integration({"@integration", "@fast", "@other"})
True
>>> fast_integration({"@system", "@fast"})
False

# Tagged with either @login or @registration
>>> auth_pages = parse("@login or @registration")
>>> auth_pages({"@account", "@login"})
True
>>> auth_pages({"@admin", "@account"})
False

Test Runner Usage

A gherkin test runner (such as behave) uses tag expressions to select scenarios to run.

# -- TAG-EXPRESSION: @one and @two
# EXPECTED: Selects and runs scenario "Three".
$ my_cucumber_test_runner --tags="@one and @two" features/example.feature
...

# -- TAG-EXPRESSION: @one or @two
# EXPECTED: Selects and runs scenarios "One", "Two" and "Three".
$ my_cucumber_test_runner --tags="@one or @two" features/example.feature
...

Such as using the following feature file.

# -- FILE: features/example.feature
Feature: Tag expressions example

  @one
  Scenario: One
    Given a step passes

  @two
  Scenario: Two
    Given another step passes

  @one @two
  Scenario: Three
    Given some step passes

  Scenario: Four
    Given another step passes