Fix assertionStarting events being sent after the expr is evaluated

Closes #2678

tests/ExtraTests/CMakeLists.txt

@@ -468,6 +468,17 @@ set_tests_properties(
 )
 
 
+add_executable(AssertionStartingEventGoesBeforeAssertionIsEvaluated
+  X20-AssertionStartingEventGoesBeforeAssertionIsEvaluated.cpp
+)
+target_link_libraries(AssertionStartingEventGoesBeforeAssertionIsEvaluated
+  PRIVATE Catch2::Catch2WithMain
+)
+add_test(
+  NAME ReporterEvents::AssertionStartingHappensBeforeAssertionIsEvaluated
+  COMMAND $<TARGET_FILE:AssertionStartingEventGoesBeforeAssertionIsEvaluated>
+)
+
 #add_executable(DebugBreakMacros ${TESTS_DIR}/X12-CustomDebugBreakMacro.cpp)
 #target_link_libraries(DebugBreakMacros Catch2)
 #add_test(NAME DebugBreakMacros COMMAND DebugBreakMacros --break)

tests/ExtraTests/X20-AssertionStartingEventGoesBeforeAssertionIsEvaluated.cpp

@@ -0,0 +1,81 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+/**\file
+ * TODO: FIXES Registers custom reporter that reports testCase* events
+ *
+ * The resulting executable can then be used by an external Python script
+ * to verify that testCase{Starting,Ended} and testCasePartial{Starting,Ended}
+ * events are properly nested.
+ */
+
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/reporters/catch_reporter_event_listener.hpp>
+#include <catch2/reporters/catch_reporter_registrars.hpp>
+#include <catch2/matchers/catch_matchers_predicate.hpp>
+
+namespace {
+
+    static size_t assertion_starting_events_seen = 0;
+
+    // TODO: custom matcher to check that "assertion_starting_events_seen" has
+    // the right number of checks
+
+    class AssertionStartingListener : public Catch::EventListenerBase {
+    public:
+        AssertionStartingListener( Catch::IConfig const* config ):
+            EventListenerBase( config ) {}
+
+        void assertionStarting( Catch::AssertionInfo const& ) override {
+            ++assertion_starting_events_seen;
+        }
+    };
+
+    static bool f1() {
+        return assertion_starting_events_seen == 1;
+    }
+
+    static void f2() {
+        if ( assertion_starting_events_seen != 2 ) { throw 1; }
+    }
+
+    static void f3() {
+        if ( assertion_starting_events_seen == 3 ) { throw 1; }
+    }
+
+    static bool f4() { return assertion_starting_events_seen == 4; }
+
+    static void f5() { throw assertion_starting_events_seen; }
+
+} // anonymous namespace
+
+CATCH_REGISTER_LISTENER( AssertionStartingListener )
+
+TEST_CASE() {
+    // **IMPORTANT**
+    // The order of assertions below matters.
+    REQUIRE( f1() );
+    REQUIRE_NOTHROW( f2() );
+    REQUIRE_THROWS( f3() );
+    REQUIRE_THAT( f4(),
+                  Catch::Matchers::Predicate<bool>( []( bool b ) { return b; } ) );
+    REQUIRE_THROWS_MATCHES(
+        f5(), size_t, Catch::Matchers::Predicate<size_t>( []( size_t i ) {
+            return i == 5;
+        } ) );
+
+    CAPTURE( assertion_starting_events_seen ); // **not** an assertion
+    INFO( "some info msg" );                   // **not** an assertion
+    WARN( "warning! warning!" );               // assertion-like message
+    SUCCEED();                                 // assertion-like message
+
+    // We skip FAIL/SKIP and so on, which fail the test.
+
+    // This require will also increment the count once
+    REQUIRE( assertion_starting_events_seen == 8 );
+}