Don't store extra copy of all TestCaseInfo* in TestRegistry

We used to store a full vector of "views" of the registered test infos,
so that it can be retrieved externally. However, the only user of that
interface left was `Session`, specifically `Session::applyFilenameAsTags`.

By moving the adding of the filename tags into the `ITestCaseRegistry`
interface, we avoid storing the vector and make the initial test registration
faster.

The new code is ugly and shows a design/layering issue, but no worse than
the previous approach did.

src/catch2/catch_registry_hub.cpp

@@ -72,6 +72,10 @@ namespace Catch {
 #endif
             }
 
+            ITestCaseRegistry& getMutableTestCaseRegistry() override {
+                return m_testCaseRegistry;
+            }
+
         private:
             TestRegistry m_testCaseRegistry;
             ReporterRegistry m_reporterRegistry;

src/catch2/catch_session.cpp

@@ -140,9 +140,7 @@ namespace Catch {
         };
 
         void applyFilenamesAsTags() {
-            for (auto const& testInfo : getRegistryHub().getTestCaseRegistry().getAllInfos()) {
-                testInfo->addFilenameTag();
-            }
+            getMutableRegistryHub().getMutableTestCaseRegistry().enableFilenameTags();
         }
 
         // Creates empty file at path. The path must be writable, we do not

src/catch2/interfaces/catch_interfaces_registry_hub.hpp

@@ -53,6 +53,8 @@ namespace Catch {
         virtual void registerTranslator( Detail::unique_ptr<IExceptionTranslator>&& translator ) = 0;
         virtual void registerTagAlias( std::string const& alias, std::string const& tag, SourceLineInfo const& lineInfo ) = 0;
         virtual void registerStartupException() noexcept = 0;
+
+        virtual ITestCaseRegistry& getMutableTestCaseRegistry() = 0;
     };
 
     IRegistryHub const& getRegistryHub();

src/catch2/interfaces/catch_interfaces_testcase.hpp

@@ -19,8 +19,7 @@ namespace Catch {
     class ITestCaseRegistry {
     public:
         virtual ~ITestCaseRegistry(); // = default
-        // TODO: this exists only for adding filenames to test cases -- let's expose this in a saner way later
-        virtual std::vector<TestCaseInfo* > const& getAllInfos() const = 0;
+        virtual void enableFilenameTags() = 0;
         virtual std::vector<TestCaseHandle> const& getAllTests() const = 0;
         virtual std::vector<TestCaseHandle> const& getAllTestsSorted( IConfig const& config ) const = 0;
     };

src/catch2/internal/catch_test_case_registry_impl.cpp

@@ -131,21 +131,21 @@ namespace Catch {
         // We pre-reserve some reasonable number of tests to avoid the
         // initial geometric growth churning during test registration.
         m_handles.reserve( kInitialTestCount );
-        m_viewed_test_infos.reserve( kInitialTestCount );
-        m_owned_test_infos.reserve( kInitialTestCount );
+        m_test_infos.reserve( kInitialTestCount );
         m_invokers.reserve( kInitialTestCount );
     }
     TestRegistry::~TestRegistry() = default;
 
     void TestRegistry::registerTest(Detail::unique_ptr<TestCaseInfo> testInfo, Detail::unique_ptr<ITestInvoker> testInvoker) {
         m_handles.emplace_back(testInfo.get(), testInvoker.get());
-        m_viewed_test_infos.push_back(testInfo.get());
-        m_owned_test_infos.push_back(CATCH_MOVE(testInfo));
+        m_test_infos.push_back(CATCH_MOVE(testInfo));
         m_invokers.push_back(CATCH_MOVE(testInvoker));
     }
 
-    std::vector<TestCaseInfo*> const& TestRegistry::getAllInfos() const {
-        return m_viewed_test_infos;
+    void TestRegistry::enableFilenameTags() {
+        for (auto& info : m_test_infos) {
+            info->addFilenameTag();
+        }
     }
 
     std::vector<TestCaseHandle> const& TestRegistry::getAllTests() const {

src/catch2/internal/catch_test_case_registry_impl.hpp

@@ -31,8 +31,8 @@ namespace Catch {
     class TestRegistry final : public ITestCaseRegistry {
     public:
         void registerTest( Detail::unique_ptr<TestCaseInfo> testInfo, Detail::unique_ptr<ITestInvoker> testInvoker );
+        void enableFilenameTags() override;
 
-        std::vector<TestCaseInfo*> const& getAllInfos() const override;
         std::vector<TestCaseHandle> const& getAllTests() const override;
         std::vector<TestCaseHandle> const& getAllTestsSorted( IConfig const& config ) const override;
 
@@ -40,12 +40,11 @@ namespace Catch {
         ~TestRegistry() override; // = default
 
     private:
-        std::vector<Detail::unique_ptr<TestCaseInfo>> m_owned_test_infos;
-        // Keeps a materialized vector for `getAllInfos`.
-        // We should get rid of that eventually (see interface note)
-        std::vector<TestCaseInfo*> m_viewed_test_infos;
-
+        // Owns the test infos for handles
+        std::vector<Detail::unique_ptr<TestCaseInfo>> m_test_infos;
+        // Owns the test invokers for handles
         std::vector<Detail::unique_ptr<ITestInvoker>> m_invokers;
+
         std::vector<TestCaseHandle> m_handles;
         mutable TestRunOrder m_currentSortOrder = TestRunOrder::Declared;
         mutable std::vector<TestCaseHandle> m_sortedFunctions;