minimal emulation of Catch2 test listing

This is the minimal emulation of the list-tests command line option that
CLion needs to discover and list tests. CLion calls the test binary with
the command line `--list-tests --order lex ~[.]` before running tests.
It doesn't seem to mind that the tests aren't actually ordered, but it
does break it's parsing if:
  - there is no leading "Matching test cases:"
  - tags aren't listed with an indent
  - tests are listed without tags

src/snitch_reporter_console.cpp

@@ -171,14 +171,19 @@ struct default_reporter_functor {
         print_message(r, e.data);
     }
 
-    void operator()(const snitch::event::list_test_run_started&) const noexcept {}
+    void operator()(const snitch::event::list_test_run_started&) const noexcept {
+        r.print("Matching test cases:\n");
+    }
 
     void operator()(const snitch::event::list_test_run_ended&) const noexcept {}
 
     void operator()(const snitch::event::test_case_listed& e) {
         small_string<max_test_name_length> full_name;
         make_full_name(full_name, e.id);
-        r.print(full_name, "\n");
+        r.print("  ", full_name, "\n");
+        if (!e.id.tags.empty()) {
+            r.print("      ", e.id.tags, "\n");
+        }
     }
 };
 } // namespace

tests/approval_tests/data/expected/reporter_console_list_tests

@@ -1,42 +1,55 @@
-test pass
-test fail
-test mayfail good pass
-test mayfail bad pass
-test shouldfail good fail
-test shouldfail bad pass
-test no tags pass
-test no tags fail
-typed test no tags pass <int>
-typed test no tags pass <float>
-typed test no tags fail <int>
-typed test no tags fail <float>
-typed test with tags pass <int>
-typed test with tags pass <float>
-typed test with tags fail <int>
-typed test with tags fail <float>
-test fixture pass
-test fixture fail
-test SUCCEED pass
-test FAIL fail
-test expression pass
-test expression fail
-test long expression pass
-test long expression fail
-test too long expression pass
-test too long expression fail
-test too long message pass
-test too long message fail
-test NOTHROW pass
-test NOTHROW fail
-test THROW pass
-test THROW fail
-test unexpected throw fail
-test unexpected throw in section fail
-test unexpected throw in check fail
-test unexpected throw in check & section fail
-test SKIP
-test INFO
-test multiple INFO
-test SECTION
-test multiple SECTION
-test SECTION & INFO
+Matching test cases:
+  test pass
+      [tag2][tag1]
+  test fail
+      [tag2][tag1]
+  test mayfail good pass
+      [tag2][tag1][!mayfail]
+  test mayfail bad pass
+      [tag2][tag1][!mayfail]
+  test shouldfail good fail
+      [tag2][tag1][!shouldfail]
+  test shouldfail bad pass
+      [tag2][tag1][!shouldfail]
+  test no tags pass
+  test no tags fail
+  typed test no tags pass <int>
+  typed test no tags pass <float>
+  typed test no tags fail <int>
+  typed test no tags fail <float>
+  typed test with tags pass <int>
+      [tag1]
+  typed test with tags pass <float>
+      [tag1]
+  typed test with tags fail <int>
+      [tag1]
+  typed test with tags fail <float>
+      [tag1]
+  test fixture pass
+      [tag with space]
+  test fixture fail
+      [tag with space]
+  test SUCCEED pass
+  test FAIL fail
+  test expression pass
+  test expression fail
+  test long expression pass
+  test long expression fail
+  test too long expression pass
+  test too long expression fail
+  test too long message pass
+  test too long message fail
+  test NOTHROW pass
+  test NOTHROW fail
+  test THROW pass
+  test THROW fail
+  test unexpected throw fail
+  test unexpected throw in section fail
+  test unexpected throw in check fail
+  test unexpected throw in check & section fail
+  test SKIP
+  test INFO
+  test multiple INFO
+  test SECTION
+  test multiple SECTION
+  test SECTION & INFO

tests/runtime_tests/registry.cpp

@@ -583,7 +583,10 @@ TEST_CASE("list tests", "[registry]") {
             CAPTURE(tag);
             console.messages.clear();
 
+            const auto header = "Matching test cases:\n"sv;
+
             framework.registry.list_tests_with_tag(tag);
+            CHECK(console.messages == contains_substring(header));
             if (tag == "[tag]"sv) {
                 CHECK(console.messages == contains_substring("how are you"));
                 CHECK(console.messages == contains_substring("how many lights"));
@@ -618,7 +621,7 @@ TEST_CASE("list tests", "[registry]") {
                 CHECK(console.messages == contains_substring("how many templated lights"));
                 CHECK(console.messages == contains_substring("hidden test 1"));
             } else if (tag == "[wrong_tag]"sv || tag == "[.hidden]"sv) {
-                CHECK(console.messages.empty());
+                CHECK(console.messages == header);
             }
         }
     }