ENH: Add SlicerStartupModuleTest.py and helper files

This adds a new python test which tries to (1) modify `sys.path` on module
load and (2) verify preservation of the changes after slicer startup.

Author: RafaelPalomar

Applications/SlicerApp/Testing/Python/CMakeLists.txt

@@ -434,6 +434,14 @@ add_test(
     ${Slicer_LAUNCHER_EXECUTABLE}
   )
 
+# Check that modules can configure environment on load
+add_test(
+  NAME py_module_configuration_startup
+  COMMAND ${PYTHON_EXECUTABLE}
+    ${CMAKE_CURRENT_SOURCE_DIR}/SlicerStartupModuleTest.py
+    ${Slicer_LAUNCHER_EXECUTABLE}
+  )
+
 # Check that stand-alone Python interpreter, without PythonQt support, can `import slicer` safely (#945)
 add_test(
   NAME py_standalonepython_import_slicer

Applications/SlicerApp/Testing/Python/SlicerStartupModuleTest.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+
+#
+#  Program: 3D Slicer
+#
+#  Copyright (c) Kitware Inc.
+#
+#  See COPYRIGHT.txt
+#  or http://www.slicer.org/copyright/copyright.txt for details.
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+#  This file was originally developed by Jean-Christophe Fillion-Robin, Kitware Inc.
+#  and was partially funded by NIH grant 1U24CA194354-01
+#
+
+import os
+import sys
+import tempfile
+
+from SlicerAppTesting import *
+
+"""
+This test verifies that a python module can add/modify python variables
+which will be preserved after Slicer startup is completed.
+
+This test was based on SlicerStartupCompletedTest.py and it relies on
+SlicerStartupModuleTestHelperModule.py and the SlicerStartupModuleTestHelperPackage
+python package
+
+It uses an output file for communication because on Windows,
+standard output is not always enabled.
+
+Usage:
+    SlicerStartupModuleTest.py /path/to/Slicer
+"""
+
+if __name__ == "__main__":
+    debug = False
+    # Set to True to:
+    #  * display the path of the expected test output file
+    #  * avoid deleting the created temporary directory
+
+    if len(sys.argv) != 2:
+        print(os.path.basename(sys.argv[0]) + " /path/to/Slicer")
+        exit(EXIT_FAILURE)
+
+    temporaryModuleDirPath = tempfile.mkdtemp().replace("\\", "/")
+    os.makedirs(temporaryModuleDirPath + "/SlicerStartupModuleTestHelperScript", exist_ok=True)
+    try:
+        # Copy helper module that creates a file when startup completed event is received
+        currentDirPath = os.path.dirname(__file__).replace("\\", "/")
+        from shutil import copyfile,copytree
+        copyfile(currentDirPath + "/SlicerStartupModuleTestHelperModule.py",
+                 temporaryModuleDirPath + "/SlicerStartupModuleTestHelperModule.py")
+        copytree(currentDirPath + "/SlicerStartupModuleTestHelperPackage",
+                 temporaryModuleDirPath + "/SlicerStartupModuleTestHelperPackage" )
+        copyfile(currentDirPath + "/SlicerStartupModuleTestHelperScript.py",
+                 temporaryModuleDirPath + "/SlicerStartupModuleTestHelperScript/SlicerStartupModuleTestHelperScript.py")
+
+        slicer_executable = os.path.expanduser(sys.argv[1])
+        common_args = [
+            "--testing",
+            "--disable-builtin-cli-modules",
+            "--disable-builtin-loadable-modules",
+            "--disable-builtin-scripted-loadable-modules",
+            "--additional-module-path", temporaryModuleDirPath,
+            "--python-script", temporaryModuleDirPath + "/SlicerStartupModuleTestHelperScript/SlicerStartupModuleTestHelperScript.py",
+        ]
+
+        test_output_file = temporaryModuleDirPath + "/StartupModuleTest.out"
+        os.environ["SLICER_STARTUP_MODULE_TEST_OUTPUT"] = test_output_file
+        if debug:
+            print("SLICER_STARTUP_MODULE_TEST_OUTPUT=%s" % test_output_file)
+
+        # Test startupCompleted with main window
+        args = list(common_args)
+        (returnCode, stdout, stderr) = runSlicer(slicer_executable, args)
+        assert returnCode == EXIT_SUCCESS
+        assert os.path.isfile(test_output_file)
+        os.remove(test_output_file)
+        print("Test startupCompleted with main window - passed\n")
+
+        # Test startupCompleted without main window
+        args = list(common_args)
+        args.extend(["--no-main-window"])
+        (returnCode, stdout, stderr) = runSlicer(slicer_executable, args)
+        assert os.path.isfile(test_output_file)
+        assert returnCode == EXIT_SUCCESS
+        print("Test startupCompleted without main window - passed\n")
+
+    finally:
+        if not debug:
+            import shutil
+            shutil.rmtree(temporaryModuleDirPath)

Applications/SlicerApp/Testing/Python/SlicerStartupModuleTestHelperModule.py

@@ -0,0 +1,23 @@
+import os
+import sys
+
+from slicer.ScriptedLoadableModule import *
+
+this_dir = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, this_dir)
+
+from SlicerStartupModuleTestHelperPackage import *
+
+class SlicerStartupModuleTestHelperModule(ScriptedLoadableModule):
+    def __init__(self, parent):
+        ScriptedLoadableModule.__init__(self, parent)
+        self.parent.title = "SlicerStartupModuleTest"
+        self.parent.categories = ["Testing.TestCases"]
+        self.parent.contributors = ["Rafael Palomar (Oslo University Hospital), Jean-Christophe Fillion-Robin (Kitware), Andras Lasso (PerkLab)"]
+        self.parent.widgetRepresentationCreationEnabled = False
+
+        self.testOutputFileName = os.environ["SLICER_STARTUP_MODULE_TEST_OUTPUT"]
+        if os.path.isfile(self.testOutputFileName):
+            os.remove(self.testOutputFileName)
+
+        print("SlicerStartupModuleTestHelperModule initialized")

Applications/SlicerApp/Testing/Python/SlicerStartupModuleTestHelperPackage/__init__.py

@@ -0,0 +1,3 @@
+import sys
+
+sys.path.insert(0, "/test/directory")

Applications/SlicerApp/Testing/Python/SlicerStartupModuleTestHelperScript.py

@@ -0,0 +1,13 @@
+import sys
+import os
+
+testOutputFileName = os.environ["SLICER_STARTUP_MODULE_TEST_OUTPUT"]
+
+if "/test/directory" not in sys.path:
+    raise RuntimeError("/test/directory not in sys.path as expected")
+
+with open(testOutputFileName, "w") as file:
+    file.write("SlicerSTartypModuleTestHelperScript.py generated this file")
+    file.write("/test/directory found in sys.path")
+
+exit(EXIT_SUCCESS)