Add support for multiversion testing with tox (#21)

Also full coverage for all supported Pythons.

Author: warsaw

.gitignore

@@ -99,3 +99,4 @@ ENV/
 
 # mypy
 .mypy_cache/
+/diffcov.html

coverage.ini

@@ -0,0 +1,26 @@
+[run]
+branch = true
+parallel = true
+omit =
+     setup*
+    .tox/*/lib/python3.*/site-packages/*
+    .tox/*/lib/python3.*/site-packages/*
+    */tests/*.py
+    /tmp/*
+    /private/var/folders/*
+    */testing/*.py
+
+[report]
+exclude_lines =
+    pragma: nocover
+    pragma: missed
+    pragma: ge${GEVER}
+    pragma: le${LEVER}
+    raise NotImplementedError
+    raise AssertionError
+    assert\s
+
+[paths]
+source =
+    importlib_resources
+    .tox/*/lib/python*/site-packages/importlib_resources

importlib_resources/__init__.py

@@ -20,15 +20,16 @@
 
 Package = Union[types.ModuleType, str]
 if sys.version_info >= (3, 6):
-    FileName = Union[str, os.PathLike]
+    FileName = Union[str, os.PathLike]              # pragma: ge36
 else:
-    FileName = str
+    FileName = str                                  # pragma: le35
 
 
 def _get_package(package) -> types.ModuleType:
     if hasattr(package, '__spec__'):
         if package.__spec__.submodule_search_locations is None:
-            raise TypeError("{!r} is not a package".format(package.__spec__.name))
+            raise TypeError("{!r} is not a package".format(
+                package.__spec__.name))
         else:
             return package
     else:
@@ -69,13 +70,13 @@ def open(package: Package, file_name: FileName) -> BinaryIO:
             # importlib.machinery loaders are and an AttributeError for
             # get_data() will make it clear what is needed from the loader.
             loader = typing.cast(importlib.abc.ResourceLoader,
-                                package.__spec__.loader)
+                                 package.__spec__.loader)
             try:
                 data = loader.get_data(full_path)
             except IOError:
                 package_name = package.__spec__.name
-                message = '{!r} resource not found in {!r}'.format(file_name,
-                                                                   package_name)
+                message = '{!r} resource not found in {!r}'.format(
+                    file_name, package_name)
                 raise FileNotFoundError(message)
             else:
                 return io.BytesIO(data)
@@ -92,8 +93,8 @@ def read(package: Package, file_name: FileName, encoding: str = 'utf-8',
     package = _get_package(package)
     # Note this is **not** builtins.open()!
     with open(package, file_name) as binary_file:
-        # Decoding from io.TextIOWrapper() instead of str.decode() in hopes that
-        # the former will be smarter about memory usage.
+        # Decoding from io.TextIOWrapper() instead of str.decode() in hopes
+        # that the former will be smarter about memory usage.
         text_file = io.TextIOWrapper(binary_file, encoding=encoding,
                                      errors=errors)
         return text_file.read()
@@ -119,8 +120,8 @@ def path(package: Package, file_name: FileName) -> Iterator[pathlib.Path]:
             return
         except FileNotFoundError:
             pass
-    # Fall-through for both the lack of resource_path() *and* if resource_path()
-    # raises FileNotFoundError.
+    # Fall-through for both the lack of resource_path() *and* if
+    # resource_path() raises FileNotFoundError.
     package_directory = pathlib.Path(package.__spec__.origin).parent
     file_path = package_directory / file_name
     if file_path.exists():

importlib_resources/abc.py

@@ -1,25 +1,32 @@
 import abc
+
 from typing.io import BinaryIO
 
 
 class ResourceReader(abc.ABC):
-
     """Abstract base class for loaders to provide resource reading support."""
 
     @abc.abstractmethod
     def open_resource(self, path: str) -> BinaryIO:
-        """Return an opened, file-like object for binary reading of the resource.
+        """Return an opened, file-like object for binary reading.
 
         The 'path' argument is expected to represent only a file name.
         If the resource cannot be found, FileNotFoundError is raised.
         """
-        raise FileNotFoundError
+        # This deliberately raises FileNotFoundError instead of
+        # NotImplementedError so that if this method is accidentally called,
+        # it'll still do the right thing.
+        raise FileNotFoundError                     # pragma: nocover
 
+    @abc.abstractmethod
     def resource_path(self, path: str) -> str:
         """Return the file system path to the specified resource.
 
         The 'path' argument is expected to represent only a file name.
         If the resource does not exist on the file system, raise
         FileNotFoundError.
         """
-        raise FileNotFoundError
+        # This deliberately raises FileNotFoundError instead of
+        # NotImplementedError so that if this method is accidentally called,
+        # it'll still do the right thing.
+        raise FileNotFoundError                     # pragma: nocover

importlib_resources/tests/test_open.py

@@ -1,7 +1,4 @@
 import io
-import os.path
-import pathlib
-import sys
 import unittest
 
 import importlib_resources as resources
@@ -33,7 +30,7 @@ def test_wrap_for_text(self):
 
     def test_FileNotFoundError(self):
         with self.assertRaises(FileNotFoundError):
-            with resources.open(self.data, 'does-not-exist') as file:
+            with resources.open(self.data, 'does-not-exist'):
                 pass
 
 

importlib_resources/tests/test_path.py

@@ -1,7 +1,3 @@
-import io
-import os.path
-import pathlib
-import sys
 import unittest
 
 import importlib_resources as resources
@@ -35,7 +31,11 @@ class PathDiskTests(PathTests, unittest.TestCase):
 
 
 class PathZipTests(PathTests, util.ZipSetup, unittest.TestCase):
-    pass
+    def test_remove_in_context_manager(self):
+        # It is not an error if the file that was temporarily stashed on the
+        # file system is removed inside the `with` stanza.
+        with resources.path(self.data, 'utf-8.file') as path:
+            path.unlink()
 
 
 if __name__ == '__main__':

importlib_resources/tests/test_read.py

@@ -1,7 +1,3 @@
-import io
-import os.path
-import pathlib
-import sys
 import unittest
 
 import importlib_resources as resources
@@ -27,8 +23,8 @@ def test_encoding(self):
 
     def test_errors(self):
         # Raises UnicodeError without the 'errors' argument.
-        result = resources.read(self.data, 'utf-16.file', encoding='utf-8',
-                                errors='ignore')
+        resources.read(
+            self.data, 'utf-16.file', encoding='utf-8', errors='ignore')
 
 
 class ReadDiskTests(ReadTests, unittest.TestCase):

importlib_resources/tests/util.py

@@ -11,7 +11,7 @@
 from . import data
 
 
-def create_package(*, file, path):
+def create_package(*, file, path, is_package=True):
     class Reader(resources_abc.ResourceReader):
         def open_resource(self, path):
             self._path = path
@@ -28,9 +28,10 @@ def resource_path(self, path_):
                 return path
 
     name = 'testingpackage'
-    spec = importlib.machinery.ModuleSpec(name, Reader(),
-                                          origin='does-not-exist',
-                                          is_package=True)
+    spec = importlib.machinery.ModuleSpec(
+        name, Reader(),
+        origin='does-not-exist',
+        is_package=is_package)
     # Unforunately importlib.util.module_from_spec() was not introduced until
     # Python 3.5.
     module = types.ModuleType(name)
@@ -80,11 +81,17 @@ def test_importing_module_as_side_effect(self):
         del sys.modules[data.__name__]
         self.execute(data.__name__, 'utf-8.file')
 
-    def test_non_package(self):
+    def test_non_package_by_name(self):
         # The anchor package cannot be a module.
         with self.assertRaises(TypeError):
             self.execute(__spec__.name, 'utf-8.file')
 
+    def test_non_package_by_package(self):
+        # The anchor package cannot be a module.
+        with self.assertRaises(TypeError):
+            module = sys.modules['importlib_resources.tests.util']
+            self.execute(module, 'utf-8.file')
+
     def test_resource_opener(self):
         data = io.BytesIO(b'Hello, world!')
         package = create_package(file=data, path=FileNotFoundError())

setup.py

@@ -0,0 +1,14 @@
+import sys
+
+from setuptools import setup
+
+
+requirements = []
+if sys.version_info < (3,):
+    requirements.append('pathlib2')
+
+
+setup(
+    name='importlib_resources',
+    install_requires=requirements,
+    )

tox.ini

@@ -0,0 +1,61 @@
+[tox]
+envlist = {py34,py35,py36,py37}-{nocov,cov,diffcov},qa
+skip_missing_interpreters = True
+
+
+[testenv]
+commands =
+    nocov: python -m unittest discover
+    cov,diffcov: python -m coverage run {[coverage]rc} -m unittest discover {posargs}
+    cov,diffcov: python -m coverage combine {[coverage]rc}
+    cov: python -m coverage html {[coverage]rc}
+    cov: python -m coverage report -m {[coverage]rc} --fail-under=100
+    diffcov: python -m coverage xml {[coverage]rc}
+    diffcov: diff-cover coverage.xml --html-report diffcov.html
+    diffcov: diff-cover coverage.xml --fail-under=100
+usedevelop = True
+passenv =
+    PYTHON*
+    LANG*
+    LC_*
+deps =
+     cov,diffcov: coverage
+     diffcov: diff_cover
+setenv =
+    cov: COVERAGE_PROCESS_START={[coverage]rcfile}
+    cov: COVERAGE_OPTIONS="-p"
+    cov: COVERAGE_FILE={toxinidir}/.coverage
+    py34: GEVER=35
+    py35: GEVER=36
+    py36: GEVER=37
+    py36: LEVER=35
+
+
+[testenv:qa]
+basepython = python3
+commands =
+    python -m flake8 importlib_resources
+    py34,py35,py36: mypy --ignore-missing-imports importlib_resources
+deps =
+    py34,py35,py36: mypy
+    flake8
+
+
+[testenv:docs]
+basepython = python3
+commands =
+    python setup.py build_sphinx
+deps:
+    sphinx
+    docutils==0.12
+
+
+[coverage]
+rcfile = {toxinidir}/coverage.ini
+rc = --rcfile={[coverage]rcfile}
+
+
+[flake8]
+hang-closing = True
+jobs = 1
+max-line-length = 79