AST-1046 Mimic python install dir at build time

pythondp3/CMakeLists.txt

 # Copyright (C) 2020 ASTRON (Netherlands Institute for Radio Astronomy)
 # SPDX-License-Identifier: GPL-3.0-or-later
 
+# Create a pseudo install directory 'dp3' in the build directory that
+# mimics the ${PYTHON_INSTALL_DIR}$ such that 'import dp3' can be used
+# in the build environment
+file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/dp3")
+configure_file("${CMAKE_CURRENT_SOURCE_DIR}/__init__.py"
+               "${CMAKE_CURRENT_BINARY_DIR}/dp3/__init__.py" COPYONLY)
+
 pybind11_add_module(pydp3 MODULE pydp3.cc)
 target_link_libraries(pydp3 PRIVATE LIBDP3)
+# Output the library/module in the pseudo install directory 'dp3'
+set_target_properties(pydp3 PROPERTIES LIBRARY_OUTPUT_DIRECTORY dp3)
 
 pybind11_add_module(parameterset MODULE parameterset.cc)
 target_link_libraries(parameterset PRIVATE LIBDP3)
+# Output the library/module in the pseudo install directory 'dp3'
+set_target_properties(parameterset PROPERTIES LIBRARY_OUTPUT_DIRECTORY dp3)
 
 install(TARGETS pydp3 parameterset DESTINATION "${PYTHON_INSTALL_DIR}/dp3")
 install(FILES __init__.py DESTINATION "${PYTHON_INSTALL_DIR}/dp3")

pythondp3/test/integration/tImportDP3.py

@@ -20,10 +20,10 @@ Script can be invoked in two ways:
 """
 
 
-def test_import_pydp3():
+def test_import_dp3():
     """
-    Test import of pydp3 module
+    Test import of dp3 module
     One reason this might fail is when the linkage of this module, a shared library,
     is incomplete. In that case, the run-time linker will report unresolved symbols.
     """
-    import pydp3
+    import dp3

steps/test/integration/testInit.sh.in

@@ -4,6 +4,9 @@
 # A test script should source this file at its start.
 # If this file is test_common.sh, CMake generated it from test_common.sh.in.
 
+import sys
+import os
+
 # Set common environment for scripts. CMake configures these variables.
 srcdir=@CMAKE_CURRENT_SOURCE_DIR@
 bindir=@CMAKE_BINARY_DIR@
@@ -12,6 +15,9 @@ dp3exe=@CMAKE_BINARY_DIR@/DP3
 makesourcedbexe=@CMAKE_BINARY_DIR@/makesourcedb
 taqlexe=@TAQL_EXECUTABLE@
 
+# Prepend the search path with the python build dir, which contains the pseudo install directory 'dp3'.
+sys.path.insert(0, os.path.join(bindir, "pythondp3"))
+
 # Create and initialize temp directory
 # FIXME: can be removed once all integration tests are converted
 # to pytest

steps/test/unit/mock/mockpystep.py

@@ -4,8 +4,8 @@
 # MockPyStep.py: simple python step, where the MockPyStep inherits from
 # the (py)dp3.DPStep class.
 
-import parameterset
-from pydp3 import Step
+from dp3 import parameterset
+from dp3 import Step
 import numpy as np