Implement simple code generation command. Closes #32

CHANGES.rst

@@ -5,6 +5,7 @@ Unreleased
 ----------
 
 - Better reporting of a not found scenario (bubenkoff)
+- Simple test code generation implemented (bubenkoff)
 
 
 2.4.0

MANIFEST.in

@@ -3,3 +3,4 @@ include README.rst
 include requirements-testing.txt
 include setup.py
 include LICENSE
+include pytest_bdd/templates/*.mak

README.rst

@@ -731,6 +731,25 @@ To have an output in json format:
     py.test --cucumberjson=<path to json report>
 
 
+Test code generation helper
+---------------------------
+
+For newcomers it's sometimes hard to write all needed test code without being frustrated.
+To simplify their life, simple code generator was implemented. It allows to create fully functional
+but of course empty tests and step definitions for given a feature file.
+It's done as a separate console script provided by pytest-bdd package:
+
+::
+
+    pytest-bdd generate <feature file name> .. <feature file nameN>
+
+It will print the generated code to the standard output so you can easily redirect it to the file:
+
+::
+
+    pytest-bdd generate features/some.feature > tests/functional/test_some.py
+
+
 Migration of your tests from versions 0.x.x-1.x.x
 -------------------------------------------------
 
@@ -743,15 +762,12 @@ decorator. Reasons for that:
   decorator more or not, so to support it along with functional approach there needed to be special parameter
   for that, which is also a backwards-incompartible change.
 
-To help users migrate to newer version, there's migration console script provided with **migrate** extra:
+To help users migrate to newer version, there's migration subcommand of the `pytest-bdd` console script:
 
 ::
 
-    # install extra for migration
-    pip install pytest-bdd[migrate]
-
     # run migration script
-    pytestbdd_migrate_tests <your test folder>
+    pytest-bdd migrate <your test folder>
 
 Under the hood the script does the replacement from this:
 

pytest_bdd/scripts.py

@@ -1,20 +1,33 @@
 """pytest-bdd scripts."""
-
-import glob2
+import argparse
+import itertools
 import os.path
 import re
-import sys
 
+import glob2
+from mako.lookup import TemplateLookup
+
+import pytest_bdd
+from pytest_bdd.feature import Feature
+
+template_lookup = TemplateLookup(directories=[os.path.join(os.path.dirname(pytest_bdd.__file__), 'templates')])
 
 MIGRATE_REGEX = re.compile(r'\s?(\w+)\s\=\sscenario\((.+)\)', flags=re.MULTILINE)
 
+PYTHON_REPLACE_REGEX = re.compile('\W')
 
-def migrate_tests():
+ALPHA_REGEX = re.compile('^\d+_*')
+
+
+def make_python_name(string):
+    """Make python attribute name out of a given string."""
+    string = re.sub(PYTHON_REPLACE_REGEX, '', string.replace(' ', '_'))
+    return re.sub(ALPHA_REGEX, '', string)
+
+
+def migrate_tests(args):
     """Migrate outdated tests to the most recent form."""
-    if len(sys.argv) != 2:
-        print('Usage: pytestbdd_migrate_tests <path>')
-        sys.exit(1)
-    path = sys.argv[1]
+    path = args.path
     for file_path in glob2.iglob(os.path.join(os.path.abspath(path), '**', '*.py')):
         migrate_tests_in_file(file_path)
 
@@ -33,3 +46,61 @@ def migrate_tests_in_file(file_path):
                 print('skipped: {0}'.format(file_path))
     except IOError:
         pass
+
+
+def check_existense(file_name):
+    """Check filename for existense."""
+    if not os.path.isfile(file_name):
+        raise argparse.ArgumentTypeError('{0} is an invalid file name'.format(file_name))
+    return file_name
+
+
+def generate_code(args):
+    """Generate test code for the given filename."""
+    features = []
+    scenarios = []
+    seen_names = set()
+    for file_name in args.files:
+        if file_name in seen_names:
+            continue
+        seen_names.add(file_name)
+        base, name = os.path.split(file_name)
+        feature = Feature.get_feature(base, name)
+        features.append(feature)
+        scenarios.extend(feature.scenarios.values())
+
+    steps = itertools.chain.from_iterable(
+        scenario.steps for scenario in scenarios)
+    steps = sorted(steps, key=lambda step: step.type)
+    seen_steps = set()
+    grouped_steps = []
+    for step in (itertools.chain.from_iterable(
+            sorted(group, key=lambda step: step.name)
+            for _, group in itertools.groupby(steps, lambda step: step.type))):
+        if step.name not in seen_steps:
+            grouped_steps.append(step)
+            seen_steps.add(step.name)
+
+    print(template_lookup.get_template('test.py.mak').render(
+        feature=features[0], scenarios=scenarios, steps=grouped_steps, make_python_name=make_python_name))
+
+
+def main():
+    """Main entry point."""
+    parser = argparse.ArgumentParser(prog='pytest-bdd')
+    subparsers = parser.add_subparsers(help='sub-command help')
+
+    parser_generate = subparsers.add_parser('generate', help='generate help')
+    parser_generate.add_argument(
+        'files', metavar='FEATURE_FILE', type=check_existense, nargs='+',
+        help='Feature files to generate test code with')
+    parser_generate.set_defaults(func=generate_code)
+
+    parser_migrate = subparsers.add_parser('migrate', help='migrate help')
+    parser_migrate.add_argument(
+        'path', metavar='PATH',
+        help='Migrate outdated tests to the most recent form')
+    parser_migrate.set_defaults(func=migrate_tests)
+
+    args = parser.parse_args()
+    args.func(args)

pytest_bdd/templates/test.py.mak

@@ -0,0 +1,24 @@
+"""${ feature.name or feature.rel_filename } feature tests."""
+from functools import partial
+
+from pytest_bdd import (given, when, then, scenario)
+
+scenario = partial(scenario, feature.filename)
+
+
+% for scenario in sorted(scenarios, key=lambda scenario: scenario.name):
+@scenario('${scenario.name}')
+def test_${ make_python_name(scenario.name)}():
+    """${scenario.name}."""
+
+
+% endfor
+% for step in steps:
+@${step.type}('${step.name}')
+def ${ make_python_name(step.name)}():
+    """${step.name}."""
+% if not loop.last:
+
+
+% endif
+% endfor

setup.py

@@ -57,6 +57,8 @@ setup(
     cmdclass={'test': Tox},
     install_requires=[
         'pytest>=2.6.0',
+        'glob2',
+        'Mako',
     ],
     # the following makes a plugin available to py.test
     entry_points={
@@ -65,12 +67,10 @@ setup(
             'pytest-bdd-cucumber-json = pytest_bdd.cucumber_json',
         ],
         'console_scripts': [
-            'pytestbdd_migrate_tests = pytest_bdd.scripts:migrate_tests [migrate]'
+            'pytest-bdd = pytest_bdd.scripts:main'
         ]
     },
     tests_require=['detox'],
-    extras_require={
-        'migrate': ['glob2']
-    },
     packages=['pytest_bdd'],
+    include_package_data=True,
 )

tests/scripts/generate.feature

@@ -0,0 +1,9 @@
+Feature: Code generation
+
+    Scenario: Given and when using the same fixture should not evaluate it twice
+        Given I have an empty list
+        And 1 have a fixture (appends 1 to a list) in reuse syntax
+
+        When I use this fixture
+
+        Then my list should be [1]

tests/scripts/test_generate.py

@@ -0,0 +1,49 @@
+"""Test code generation command."""
+import os
+import sys
+import textwrap
+
+from pytest_bdd.scripts import main
+
+PATH = os.path.dirname(__file__)
+
+
+def test_generate(monkeypatch, capsys):
+    """Test if the code is generated by a given feature."""
+    monkeypatch.setattr(sys, 'argv', ['', 'generate', os.path.join(PATH, 'generate.feature')])
+    main()
+    out, err = capsys.readouterr()
+    assert out == textwrap.dedent('''
+    """Code generation feature tests."""
+    from functools import partial
+
+    from pytest_bdd import (given, when, then, scenario)
+
+    scenario = partial(scenario, feature.filename)
+
+
+    @scenario('Given and when using the same fixture should not evaluate it twice')
+    def test_Given_and_when_using_the_same_fixture_should_not_evaluate_it_twice():
+        """Given and when using the same fixture should not evaluate it twice."""
+
+
+    @given('1 have a fixture (appends 1 to a list) in reuse syntax')
+    def have_a_fixture_appends_1_to_a_list_in_reuse_syntax():
+        """1 have a fixture (appends 1 to a list) in reuse syntax."""
+
+
+    @given('I have an empty list')
+    def I_have_an_empty_list():
+        """I have an empty list."""
+
+
+    @then('my list should be [1]')
+    def my_list_should_be_1():
+        """my list should be [1]."""
+
+
+    @when('I use this fixture')
+    def I_use_this_fixture():
+        """I use this fixture."""
+
+    '''[1:].replace(u"'", u"'"))

tox.ini

@@ -22,12 +22,6 @@ deps =
     hg+https://bitbucket.org/hpk42/py#egg=py
     hg+https://bitbucket.org/hpk42/pytest#egg=pytest
 
-[testenv:py27-pytest-2.4.2]
-basepython=python2.7
-deps =
-    {[testenv]deps}
-    pytest==2.4.2
-
 [pytest]
 pep8maxlinelength=120
 addopts=-vvl