fix(complex-numbers): use runner's Catch2 version (#996)

The test runner uses Catch2 v3.4.0, while locally we still had v2.13.6. The
recent changes to the complex-numbers test work with v2.13.6, while they don't
work with v3.4.0, causing compilation to always fail in the test runner. This
commit changes the test to be compatible with v3.4.0 and updates the local
Catch2 copy.

Author: ahans

.pre-commit-config.yaml

@@ -1,4 +1,4 @@
-exclude: 'test/(catch.hpp|tests-main.cpp)'
+exclude: 'test/(catch(_amalgamated)?.[ch]pp|tests-main.cpp)'
 
 repos:
 -   repo: https://github.com/pre-commit/mirrors-clang-format

exercises/practice/complex-numbers/CMakeLists.txt

@@ -17,11 +17,7 @@ else()
     set(exercise_cpp "")
 endif()
 
-# Use the common Catch library?
-if(EXERCISM_COMMON_CATCH)
-    # For Exercism track development only
-    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h $<TARGET_OBJECTS:catchlib>)
-elseif(EXERCISM_TEST_SUITE)
+if(EXERCISM_TEST_SUITE)
     # The Exercism test suite is being run, the Docker image already
     # includes a pre-built version of Catch.
     find_package(Catch2 REQUIRED)
@@ -32,7 +28,11 @@ elseif(EXERCISM_TEST_SUITE)
     target_compile_definitions(${exercise} PRIVATE EXERCISM_TEST_SUITE)
 else()
     # Build executable from sources and headers
-    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h test/tests-main.cpp)
+    # Other exercises have a third case where we use a local Catch2 copy from `test/`,
+    # which then only needs to be built once and not individually for each exercise.
+    # However, for complex-numbers we currently use a different version of Catch2 and
+    # therefore always build the version local to the exercise.
+    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h test/catch_amalgamated.cpp test/tests-main.cpp)
 endif()
 
 set_target_properties(${exercise} PROPERTIES

exercises/practice/complex-numbers/complex_numbers_test.cpp

@@ -6,7 +6,7 @@
 #ifdef EXERCISM_TEST_SUITE
 #include <catch2/catch.hpp>
 #else
-#include "test/catch.hpp"
+#include "test/catch_amalgamated.hpp"
 #endif
 
 // Complex Numbers exercise test case data version 1.3.0
@@ -26,7 +26,7 @@ using complex_numbers::Complex;
 static constexpr double eps = 0.005;
 
 // Custom Catch2 matcher for approximate equality of Complex numbers
-class ComplexApproxMatcher : public Catch::MatcherBase<Complex> {
+class ComplexApproxMatcher : public Catch::Matchers::MatcherBase<Complex> {
    public:
     ComplexApproxMatcher(const Complex& expected, double epsilon)
         : expected{expected}, epsilon{epsilon} {}