* Implemented a wrapper module around the standard argparse package, exposing the same interface with some extras on top, including a new builder type with expressive DSL for constructing complex argument parsers.
* Fixed imports in build_swift/argparse/__init__.py to make flake8 happy.
* More re-formmating to meet the exacting standards of the python_lint script.
* Added doc-strings to all the modules in the build_swift argparse overlay.
* Implemented a new BoolType for the argparse module which handles boolean-like values and replaces the hard-coded boolean values in the _ToggleAction class.
* Fixed the mess of imports in the tests sub-package to favor relative imports, so now the unit-tests will actually run as expected. The README has also been updated with a better command for executing the unit-test suite.
* Updated the add_positional method on the ArgumentParser builder class to only take a single action or default to the store action.
* Cleaned up the set_defaults method.
* Added validation test to run the build_swift unit-tests.
* Updated validation-test for the build_swift unit-test suite to use %utils.
* Fixed hard-coded default values in the expected_options module used for generating argument parser tests.
* Updated the comment in the Python validation test to run the build_swift unit-tests.
* Moved argument-defaults logic that should be determined outside the actual parser back into the build-script. This logic will be relocated again at a later date to a more suitable module with testing.
* Moved test-paths argument default logic into build-script until it can find a better home in the future.
* Removed old default value for stdlib_deployment_targets from the expected options.
* Updated the argument-parsing test suite to use a more declarative set of Option classes and included a new test for exhaustiveness which should assure that we are always testing every possible option available in the parser.
* Added a new test to check that all the expected options have default values.
* Converted default values to use the defaults module where appropriate to make the test suite more portable since the original hard-coded values were gathered from my development machine.
Sometimes it's useful to be able to run tests located in specific
directories and/or files, let's enable this in `utils/build-script`
using `--test-paths` option which accepts a list of viable test locations.
Resolves: rdar://problem/32004487
* Added new OptionalTrueAction and OptionalFalseAction classes to the arguments module.
* Fixed missing return statement in help-test generator.
* Renamed all the `skip_build_*` names to the more simple and affirmative `build_*`.
* Renamed all the `skip_test_*` names to the more simple and affirmative `test_*`.
* Added documentation to the OptionalTrueAction and OptionalFalseAction classes.
* Implemented a (mostly) comprehensive test suite for the argument parser (ab)using metaclasses to dynamically generate unit-tests for each valid argument and preset.
* Fixed failing defaults test for build_ninja.
* Added new HelpOption and IgnoreOption classes for generating tests.
* Converted default value test into individual generated tests which should give better output in case the default tests fail.
