Make TraitsUI, Pyface and configobj optional dependencies (#351)

Apptools contains several disparate packages with different needs. While
it's somewhat reasonable to regard Traits as a core dependency, not all
subpackages need a GUI, and only the preferences package makes use of
configobj.

This PR:

* makes all three of TraitsUI, Pyface and configobj optional
dependencies
* adds a "gui" entry for `extras_require` in `setup.py`
* adds a test workflow that runs the test suite with only the core
dependencies (i.e., Traits), to make sure that other tests are skipped
appropriately rather than failing

Closes #70 

Makes #86 obsolete.

.github/workflows/test-minimal-dependencies.yml

@@ -0,0 +1,29 @@
+name: Test with minimal dependencies
+
+on:
+- pull_request
+- workflow_dispatch
+
+jobs:
+  tests:
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+    - name: Get apptools source
+      uses: actions/checkout@v4
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install local package
+      run: python -m pip install ".[test]"
+    - name: Run tests
+      run: |
+        mkdir testdir
+        cd testdir
+        python -m unittest discover -v apptools

.github/workflows/test-with-pip.yml

@@ -21,10 +21,10 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies and local packages (not macOS)
-      run: python -m pip install .[h5,preferences]
+      run: python -m pip install .[gui,h5,preferences]
       if: matrix.os != 'macos-latest'
     - name: Install dependencies and local packages (macOS)
-      run: python -m pip install .[preferences]
+      run: python -m pip install .[gui,preferences]
       # PyTables currently won't build on Apple Silicon, so exclude the h5 deps
       # xref: enthought/apptools/issues/344
       if: matrix.os == 'macos-latest'

apptools/_testing/optional_dependencies.py

@@ -45,3 +45,14 @@ def optional_import(name):
 
 tables = optional_import("tables")
 requires_tables = unittest.skipIf(tables is None, "PyTables not available")
+
+configobj = optional_import("configobj")
+requires_configobj = unittest.skipIf(
+    configobj is None, "configobj not available"
+)
+
+pyface = optional_import("pyface")
+requires_pyface = unittest.skipIf(pyface is None, "Pyface not available")
+
+traitsui = optional_import("traitsui")
+requires_traitsui = unittest.skipIf(traitsui is None, "TraitsUI not available")

apptools/logger/plugin/tests/test_logger_service.py

@@ -11,9 +11,13 @@
 import unittest
 from unittest import mock
 
-from apptools.logger.plugin.logger_service import LoggerService
+from apptools._testing.optional_dependencies import pyface, requires_pyface
 
+if pyface is not None:
+    from apptools.logger.plugin.logger_service import LoggerService
 
+
+@requires_pyface
 class LoggerServiceTestCase(unittest.TestCase):
     def test_create_email_message(self):
         logger_service = LoggerService()

apptools/preferences/tests/test_preference_binding.py

@@ -26,6 +26,8 @@
 from apptools.preferences.api import Preferences
 from apptools.preferences.api import bind_preference
 from apptools.preferences.api import set_default_preferences
+from apptools._testing.optional_dependencies import requires_configobj
+
 from traits.api import Bool, HasTraits, Int, Float, Str, TraitError
 from traits.observation.api import match
 
@@ -43,6 +45,7 @@ def listener(event):
     listener.new = event.new
 
 
+@requires_configobj
 class PreferenceBindingTestCase(unittest.TestCase):
     """ Tests for preference bindings. """
 

apptools/preferences/tests/test_preferences.py

@@ -23,13 +23,15 @@
     from importlib_resources import files
 
 # Enthought library imports.
+from apptools._testing.optional_dependencies import requires_configobj
 from apptools.preferences.api import Preferences
 
 
 # This module's package.
 PKG = "apptools.preferences.tests"
 
 
+@requires_configobj
 class PreferencesTestCase(unittest.TestCase):
     """ Tests for preferences nodes. """
 

apptools/preferences/tests/test_preferences_helper.py

@@ -26,6 +26,8 @@
 from apptools.preferences.api import Preferences, PreferencesHelper
 from apptools.preferences.api import ScopedPreferences
 from apptools.preferences.api import set_default_preferences
+from apptools._testing.optional_dependencies import requires_configobj
+
 from traits.api import (
     Any, Bool, HasTraits, Int, Float, List, Str, TraitError,
     push_exception_handler, pop_exception_handler,
@@ -53,6 +55,7 @@ def bgcolor_listener(event):
 PKG = "apptools.preferences.tests"
 
 
+@requires_configobj
 class PreferencesHelperTestCase(unittest.TestCase):
     """ Tests for the preferences helper. """
 

apptools/preferences/ui/tests/test_preferences_page.py

@@ -16,12 +16,16 @@
     pop_exception_handler,
     push_exception_handler,
 )
-from traitsui.api import Group, Item, View
 
 from apptools.preferences.api import Preferences
-from apptools.preferences.ui.api import PreferencesPage
+from apptools._testing.optional_dependencies import requires_traitsui, traitsui
 
+if traitsui is not None:
+    from traitsui.api import Group, Item, View
+    from apptools.preferences.ui.api import PreferencesPage
 
+
+@requires_traitsui
 class TestPreferencesPage(unittest.TestCase):
     """ Non-GUI Tests for PreferencesPage."""
 

docs/releases/upcoming/351.build.rst

@@ -0,0 +1,3 @@
+TraitsUI, Pyface and configobj are now optional dependencies. TraitsUI
+and Pyface will be installed with ``pip install apptools[gui]``. configobj
+will be installed with ``pip install apptools[preferences]``. (#351)

setup.py

@@ -302,16 +302,16 @@ def get_long_description():
                 'preferences/tests/*.ini'
             ]
         },
-        install_requires=[
-            'configobj',
-            'traits>=6.2.0',
-            'traitsui',
-        ],
+        install_requires=['traits>=6.2.0'],
         extras_require={
             "docs": ["enthought-sphinx-theme", "sphinx"],
             "test": [
                 "importlib-resources>=1.1.0; python_version<'3.9'",
             ],
+            "gui": [
+                "pyface",
+                "traitsui",
+            ],
             "h5": [
                 # PyTables is currently incompatible with NumPy 2.0
                 # xref: enthought/apptools#345