Add unit tests for getting MFEM coefficients for functions

src/problem/MFEMProblem.C

@@ -293,9 +293,9 @@ MFEMProblem::addFunction(const std::string & type,
   }
   else
   {
-    mooseWarning("Could not identify whether function time ",
+    mooseWarning("Could not identify whether function ",
                  type,
-                 "is scalar or vector; no MFEM coefficient object created.");
+                 " is scalar or vector; no MFEM coefficient object created.");
   }
 }
 

unit/src/FunctionTest.C

@@ -0,0 +1,78 @@
+#include "MFEMObjectUnitTest.h"
+
+class FunctionTest : public MFEMObjectUnitTest
+{
+public:
+  mfem::IsoparametricTransformation fe_transform;
+  mfem::IntegrationPoint point;
+  FunctionTest() : MFEMObjectUnitTest("PlatypusApp")
+  {
+    point.Init(3);
+    point.Set3(0., 0., 0.);
+    fe_transform.SetIdentityTransformation(mfem::Geometry::CUBE);
+  }
+};
+
+/**
+ * Test MFEMProblem::getScalarFunctionCoefficient works as it should.
+ */
+TEST_F(FunctionTest, GetScalarFunctionCoefficient)
+{
+  // Build required kernel inputs
+  InputParameters func_params1 = _factory.getValidParams("ParsedFunction");
+  func_params1.set<std::string>("expression") = "1.";
+  _mfem_problem->addFunction("ParsedFunction", "coef1", func_params1);
+  _mfem_problem->getFunction("coef1").initialSetup();
+  std::shared_ptr<mfem::Coefficient> coef = _mfem_problem->getScalarFunctionCoefficient("coef1");
+  EXPECT_EQ(coef->Eval(fe_transform, point), 1);
+
+  EXPECT_THROW(_mfem_problem->getVectorFunctionCoefficient("coef1"), std::runtime_error);
+  EXPECT_THROW(_mfem_problem->getScalarFunctionCoefficient("coef2"), std::runtime_error);
+}
+
+/**
+ * Test MFEMProblem::getVectorFunctionCoefficient works as it should.
+ */
+TEST_F(FunctionTest, GetVectorFunctionCoefficient)
+{
+  // Build required kernel inputs
+  InputParameters func_params1 = _factory.getValidParams("ParsedVectorFunction");
+  func_params1.set<std::string>("expression_x") = "1.";
+  func_params1.set<std::string>("expression_y") = "2.";
+  func_params1.set<std::string>("expression_z") = "3.";
+  _mfem_problem->addFunction("ParsedVectorFunction", "vec_coef1", func_params1);
+  _mfem_problem->getFunction("vec_coef1").initialSetup();
+  std::shared_ptr<mfem::VectorCoefficient> coef =
+      _mfem_problem->getVectorFunctionCoefficient("vec_coef1");
+  mfem::Vector vec;
+  coef->Eval(vec, fe_transform, point);
+  EXPECT_EQ(vec[0], 1.);
+  EXPECT_EQ(vec[1], 2.);
+  EXPECT_EQ(vec[2], 3.);
+
+  EXPECT_THROW(_mfem_problem->getVectorFunctionCoefficient("vec_coef2"), std::runtime_error);
+  EXPECT_THROW(_mfem_problem->getScalarFunctionCoefficient("vec_coef1"), std::runtime_error);
+}
+
+/**
+ * Test MFEMProblem::addFunction when unkown function type is used.
+ */
+TEST_F(FunctionTest, AddUnknownFunction)
+{
+  InputParameters func_params1 = _factory.getValidParams("ParsedFunction");
+  func_params1.set<std::string>("expression") = "1.";
+  _mfem_problem->addFunction("ParsedFunction", "coef1", func_params1);
+  InputParameters func_params2 = _factory.getValidParams("ParsedFunction");
+  func_params2.set<std::string>("expression") = "x*y";
+  _mfem_problem->addFunction("ParsedFunction", "coef2", func_params2);
+  InputParameters func_params3 = _factory.getValidParams("LinearCombinationFunction");
+  func_params3.set<std::vector<FunctionName>>("functions") = {"coef1", "coef2"};
+  func_params3.set<std::vector<double>>("w") = {1., 2.};
+  _mfem_problem->addFunction("LinearCombinationFunction", "coef3", func_params3);
+  _mfem_problem->getFunction("coef1").initialSetup();
+  _mfem_problem->getFunction("coef2").initialSetup();
+  _mfem_problem->getFunction("coef3").initialSetup();
+
+  EXPECT_THROW(_mfem_problem->getScalarFunctionCoefficient("coef3"), std::runtime_error);
+  EXPECT_THROW(_mfem_problem->getVectorFunctionCoefficient("coef3"), std::runtime_error);
+}