Test internals of LinExpr

Author: hedtke

include/scippp/lin_expr.hpp

@@ -5,6 +5,10 @@
 
 #include "scippp/var.hpp"
 
+// just for tests, see test_linexpr.cpp
+namespace LinExpression { // NOLINT(readability-identifier-naming)
+struct CheckInternalsUsingFriendStruct;
+}
 namespace scippp {
 
 /**
@@ -13,6 +17,7 @@ namespace scippp {
  */
 class LinExpr {
     friend class Model;
+    friend struct LinExpression::CheckInternalsUsingFriendStruct; // just for tests, see test_linexpr.cpp
     //! Constant term.
     double m_constant { 0.0 };
     //! Variables in the linear combination.

test/test_linexpr.cpp

@@ -1,5 +1,7 @@
 #include <boost/test/unit_test.hpp>
 
+#include <algorithm>
+
 #include "scippp/model.hpp"
 #include "scippp/solving_statistics.hpp"
 
@@ -98,4 +100,28 @@ BOOST_AUTO_TEST_CASE(AddInitializerList)
     BOOST_TEST(model.getSolvingStatistic(statistics::PRIMALBOUND) == 1);
 }
 
+BOOST_AUTO_TEST_CASE(CheckInternalsUsingFriendStruct)
+{
+    const double VAL { 2.0 };
+    for (size_t num { 1 }; num < 4; ++num) {
+        Model m("m");
+        const auto VARS = m.addVars("x", num);
+
+        LinExpr lDef(VARS);
+        BOOST_TEST(lDef.getConstant() == 0);
+        BOOST_TEST(lDef.m_constant == 0);
+        BOOST_TEST(lDef.m_vars.size() == num);
+        BOOST_TEST(lDef.m_coeffs.size() == num);
+        BOOST_TEST(all_of(lDef.m_coeffs.begin(), lDef.m_coeffs.end(), [](double d) { return d == 1; }));
+
+        const vector COEFF(num, VAL);
+        LinExpr lCoeff(VARS, COEFF);
+        BOOST_TEST(lCoeff.getConstant() == 0);
+        BOOST_TEST(lCoeff.m_constant == 0);
+        BOOST_TEST(lCoeff.m_vars.size() == num);
+        BOOST_TEST(lCoeff.m_coeffs.size() == num);
+        BOOST_TEST(all_of(lCoeff.m_coeffs.begin(), lCoeff.m_coeffs.end(), [&VAL](double d) { return d == VAL; }));
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()