From 24cec51e85fff17dc3f8460f05645bb50e798028 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Mon, 12 Oct 2020 06:17:16 -0400
Subject: [PATCH] add tests for using python invoke and python style variables

---
 unittest/python/CMakeLists.txt          |  2 +
 unittest/python/func.py                 | 18 ++++++++
 unittest/python/test_python_package.cpp | 56 +++++++++++++++++++++++--
 3 files changed, 73 insertions(+), 3 deletions(-)
 create mode 100644 unittest/python/func.py

diff --git a/unittest/python/CMakeLists.txt b/unittest/python/CMakeLists.txt
index 0c3b0e9418..47fdbbfb2d 100644
--- a/unittest/python/CMakeLists.txt
+++ b/unittest/python/CMakeLists.txt
@@ -3,8 +3,10 @@
 # from the executable, so the shared library is not needed. The
 # availability of the PYTHON package is tested for inside the tester.
 
+set(TEST_INPUT_FOLDER ${CMAKE_CURRENT_SOURCE_DIR})
 add_executable(test_python_package test_python_package.cpp)
 target_link_libraries(test_python_package PRIVATE lammps GTest::GMock GTest::GTest)
+target_compile_definitions(test_python_package PRIVATE -DTEST_INPUT_FOLDER=${TEST_INPUT_FOLDER})
 add_test(NAME PythonPackage COMMAND test_python_package WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 set_tests_properties(PythonPackage PROPERTIES ENVIRONMENT "LAMMPS_POTENTIALS=${LAMMPS_POTENTIALS_DIR};PYTHONPATH=${CMAKE_CURRENT_BINARY_DIR}:${LAMMPS_PYTHON_DIR}:$ENV{PYTHONPATH}")
 
diff --git a/unittest/python/func.py b/unittest/python/func.py
new file mode 100644
index 0000000000..27704660a6
--- /dev/null
+++ b/unittest/python/func.py
@@ -0,0 +1,18 @@
+
+from __future__ import print_function
+
+def square(val):
+    return val*val
+
+def printnum():
+    print("2.25")
+
+def printtxt():
+    print("sometext")
+
+def getidxvar(lmpptr):
+    from lammps import lammps, LMP_VAR_EQUAL
+    lmp = lammps(ptr=lmpptr)
+
+    val = lmp.extract_variable("idx",None,LMP_VAR_EQUAL)
+    print(val)
diff --git a/unittest/python/test_python_package.cpp b/unittest/python/test_python_package.cpp
index dfbb8086c5..db8320aa91 100644
--- a/unittest/python/test_python_package.cpp
+++ b/unittest/python/test_python_package.cpp
@@ -20,14 +20,19 @@
 #include <cstring>
 #include <vector>
 
+// location of '*.py' files required by tests
+#define STRINGIFY(val) XSTR(val)
+#define XSTR(val) #val
+std::string INPUT_FOLDER = STRINGIFY(TEST_INPUT_FOLDER);
+
 // whether to print verbose output (i.e. not capturing LAMMPS screen output).
 bool verbose = false;
 
 using LAMMPS_NS::utils::split_words;
 
 namespace LAMMPS_NS {
-using ::testing::Eq;
-
+using ::testing::StrEq;
+using ::testing::MatchesRegex;
 
 class PythonPackageTest : public ::testing::Test {
 protected:
@@ -52,6 +57,7 @@ protected:
         lmp->input->one("pair_style zero 2.0");
         lmp->input->one("pair_coeff * *");
         lmp->input->one("mass * 1.0");
+        lmp->input->one("variable input_dir index " + INPUT_FOLDER);
         if (!verbose) ::testing::internal::GetCapturedStdout();
     }
 
@@ -65,8 +71,52 @@ protected:
 
 TEST_F(PythonPackageTest, python_invoke)
 {
+    // execute python function from file
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("python printnum file ${input_dir}/func.py");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ::testing::internal::CaptureStdout();
+    lmp->input->one("python printnum invoke");
+    std::string output = ::testing::internal::GetCapturedStdout();
+    if (verbose) std::cout << output;
+    ASSERT_THAT(output, MatchesRegex("python.*2.25.*"));
+
+    // execute another python function from same file
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("python printtxt exists");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ::testing::internal::CaptureStdout();
+    lmp->input->one("python printtxt invoke");
+    output = ::testing::internal::GetCapturedStdout();
+    if (verbose) std::cout << output;
+    ASSERT_THAT(output, MatchesRegex("python.*sometext.*"));
+
+    // execute python function that uses the LAMMPS python module
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("variable idx equal 2.25");
+    lmp->input->one("python getidxvar input 1 SELF format p exists");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ::testing::internal::CaptureStdout();
+    lmp->input->one("python getidxvar invoke");
+    output = ::testing::internal::GetCapturedStdout();
+    if (verbose) std::cout << output;
+    ASSERT_THAT(output, MatchesRegex("python.*2.25.*"));
 }
-    
+
+    TEST_F(PythonPackageTest, python_variable)
+{
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("variable sq python square");
+    lmp->input->one("variable val index 1.5");
+    lmp->input->one("python square input 1 v_val return v_sq format ff file ${input_dir}/func.py");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ::testing::internal::CaptureStdout();
+    lmp->input->one("print \"${sq}\"");
+    std::string output = ::testing::internal::GetCapturedStdout();
+    if (verbose) std::cout << output;
+    ASSERT_THAT(output, MatchesRegex("print.*2.25.*"));
+}
+
 } // namespace LAMMPS_NS
 
 int main(int argc, char **argv)