feat: add AppHandler methods, get_distribution() and get_version()

src/wuttjamaican/app.py

@@ -152,6 +152,90 @@ class AppHandler:
         return self.config.get(f'{self.appname}.app_title',
                                default=default or self.default_app_title)
 
+    def get_distribution(self, obj=None):
+        """
+        Returns the appropriate Python distribution name.
+
+        If ``obj`` is specified, this will attempt to locate the
+        distribution based on the top-level module which contains the
+        object's type/class.
+
+        If ``obj`` is *not* specified, this behaves a bit differently.
+        It first will look for a :term:`config setting` named
+        ``wutta.app_dist`` (or similar, dpending on :attr:`appname`).
+        If there is such a config value, it is returned.  Otherwise
+        the "auto-locate" logic described above happens, but using
+        ``self`` instead of ``obj``.
+
+        In other words by default this returns the distribution to
+        which the running :term:`app handler` belongs.
+
+        See also :meth:`get_version()`.
+
+        :param obj: Any object which may be used as a clue to locate
+           the appropriate distribution.
+
+        :returns: string, or ``None``
+
+        Also note that a *distribution* name is different from a
+        *package* name.  The distribution name is how things appear on
+        PyPI for instance.
+
+        If you want to override the default distribution name (and
+        skip the auto-locate based on app handler) then you can define
+        it in config:
+
+        .. code-block:: ini
+
+           [wutta]
+           app_dist = My-Poser-Dist
+        """
+        if obj is None:
+            print(self.appname)
+            dist = self.config.get(f'{self.appname}.app_dist')
+            if dist:
+                return dist
+
+        # TODO: do we need a config setting for app_package ?
+        #modpath = self.config.get(f'{self.appname}.app_package')
+        modpath = None
+        if not modpath:
+            modpath = type(obj if obj is not None else self).__module__
+        pkgname = modpath.split('.')[0]
+
+        try:
+            from importlib.metadata import packages_distributions
+        except ImportError:     # python < 3.10
+            from importlib_metadata import packages_distributions
+
+        pkgmap = packages_distributions()
+        if pkgname in pkgmap:
+            dist = pkgmap[pkgname][0]
+            return dist
+
+        # fall back to configured dist, if obj lookup failed
+        if obj is not None:
+            return self.config.get(f'{self.appname}.app_dist')
+
+    def get_version(self, dist=None, obj=None):
+        """
+        Returns the version of a given Python distribution.
+
+        If ``dist`` is not specified, calls :meth:`get_distribution()`
+        to get it.  (It passes ``obj`` along for this).
+
+        So by default this will return the version of whichever
+        distribution owns the running :term:`app handler`.
+
+        :returns: Version as string.
+        """
+        from importlib.metadata import version
+
+        if not dist:
+            dist = self.get_distribution(obj=obj)
+        if dist:
+            return version(dist)
+
     def get_model(self):
         """
         Returns the :term:`app model` module.

tests/test_app.py

@@ -2,6 +2,7 @@
 
 import os
 import shutil
+import sys
 import tempfile
 import warnings
 from unittest import TestCase
@@ -116,6 +117,88 @@ class TestAppHandler(TestCase):
     def test_get_title(self):
         self.assertEqual(self.app.get_title(), 'WuttJamaican')
 
+    def test_get_distribution(self):
+
+        # default should always be WuttJamaican (right..?)
+        dist = self.app.get_distribution()
+        self.assertEqual(dist, 'WuttJamaican')
+
+        # also works with "non-native" objects
+        from config import Configuration
+        config = Configuration({})
+        dist = self.app.get_distribution(config)
+        self.assertEqual(dist, 'python-configuration')
+
+        # can override dist via config
+        self.config.setdefault('wuttatest.app_dist', 'importlib_metadata')
+        dist = self.app.get_distribution()
+        self.assertEqual(dist, 'importlib_metadata')
+
+        # but the provided object takes precedence
+        dist = self.app.get_distribution(config)
+        self.assertEqual(dist, 'python-configuration')
+
+    def test_get_distribution_pre_python_3_10(self):
+
+        # the goal here is to get coverage for code which would only
+        # run on python 3,9 and older, but we only need that coverage
+        # if we are currently testing python 3.10+
+        if sys.version_info.major == 3 and sys.version_info.minor < 10:
+            pytest.skip("this test is not relevant before python 3.10")
+
+        importlib_metadata = MagicMock()
+        importlib_metadata.packages_distributions = MagicMock(
+            return_value={
+                'wuttjamaican': ['WuttJamaican'],
+                'config': ['python-configuration'],
+            })
+
+        orig_import = __import__
+
+        def mock_import(name, *args, **kwargs):
+            if name == 'importlib.metadata':
+                raise ImportError
+            if name == 'importlib_metadata':
+                return importlib_metadata
+            return orig_import(name, *args, **kwargs)
+
+        with patch('builtins.__import__', side_effect=mock_import):
+
+            # default should always be WuttJamaican (right..?)
+            dist = self.app.get_distribution()
+            self.assertEqual(dist, 'WuttJamaican')
+
+            # also works with "non-native" objects
+            from config import Configuration
+            config = Configuration({})
+            dist = self.app.get_distribution(config)
+            self.assertEqual(dist, 'python-configuration')
+
+            # hacky sort of test, just in case we can't deduce the
+            # package dist based on the obj - easy enough since we
+            # have limited the packages_distributions() above
+            dist = self.app.get_distribution(42)
+            self.assertIsNone(dist)
+
+            # can override dist via config
+            self.config.setdefault('wuttatest.app_dist', 'importlib_metadata')
+            dist = self.app.get_distribution()
+            self.assertEqual(dist, 'importlib_metadata')
+
+            # but the provided object takes precedence
+            dist = self.app.get_distribution(config)
+            self.assertEqual(dist, 'python-configuration')
+
+            # hacky test again, this time config override should win
+            dist = self.app.get_distribution(42)
+            self.assertEqual(dist, 'importlib_metadata')
+
+    def test_get_version(self):
+        from importlib.metadata import version
+
+        # default should always be for WuttJamaican (right..?)
+        self.assertEqual(self.app.get_version(), version('WuttJamaican'))
+
     def test_make_title(self):
         text = self.app.make_title('foo_bar')
         self.assertEqual(text, "Foo Bar")