refs #12080 - testrunner: do not create test implementation until it …

…is used (#6691)

Greatly improves the start-up time because it no longer needs to create
all the implementations before it runs any test.

The following times are using a debug build.

Before: `bin/testrunner TestColor 1,16s user 0,07s system 99% cpu 1,235
total`

After: `bin/testrunner TestColor 0,00s user 0,00s system 88% cpu 0,009
total`

test/fixture.cpp

@@ -41,12 +41,12 @@
  **/
 namespace {
     struct CompareFixtures {
-        bool operator()(const TestFixture* lhs, const TestFixture* rhs) const {
+        bool operator()(const TestInstance* lhs, const TestInstance* rhs) const {
             return lhs->classname < rhs->classname;
         }
     };
 }
-using TestSet = std::set<TestFixture*, CompareFixtures>;
+using TestSet = std::set<TestInstance*, CompareFixtures>;
 namespace {
     class TestRegistry {
         TestSet _tests;
@@ -57,7 +57,7 @@ namespace {
             return testreg;
         }
 
-        void addTest(TestFixture *t) {
+        void addTest(TestInstance *t) {
             _tests.insert(t);
         }
 
@@ -67,7 +67,11 @@ namespace {
     };
 }
 
-
+TestInstance::TestInstance(const char * _name)
+    : classname(_name)
+{
+    TestRegistry::theInstance().addTest(this);
+}
 
 
 /**
@@ -83,9 +87,7 @@ std::size_t TestFixture::succeeded_todos_counter = 0;
 
 TestFixture::TestFixture(const char * const _name)
     : classname(_name)
-{
-    TestRegistry::theInstance().addTest(this);
-}
+{}
 
 
 bool TestFixture::prepareTest(const char testname[])
@@ -389,10 +391,11 @@ std::size_t TestFixture::runTests(const options& args)
             classname.erase(classname.find("::"));
         }
 
-        for (TestFixture * test : TestRegistry::theInstance().tests()) {
+        for (TestInstance * test : TestRegistry::theInstance().tests()) {
             if (classname.empty() || test->classname == classname) {
-                test->processOptions(args);
-                test->run(testname);
+                TestFixture* fixture = test->create();
+                fixture->processOptions(args);
+                fixture->run(testname);
             }
         }
     }

test/fixture.h

@@ -283,6 +283,18 @@ class TestFixture : public ErrorLogger {
     static std::size_t runTests(const options& args);
 };
 
+class TestInstance {
+public:
+    explicit TestInstance(const char * _name);
+    virtual ~TestInstance() = default;
+
+    virtual TestFixture* create() = 0;
+
+    const std::string classname;
+protected:
+    std::unique_ptr<TestFixture> impl;
+};
+
 // TODO: most asserts do not actually assert i.e. do not return
 #define TEST_CASE( NAME )  do { if (prepareTest(#NAME)) { setVerbose(false); try { NAME(); teardownTest(); } catch (...) { assertNoThrowFail(__FILE__, __LINE__); } } } while (false)
 #define ASSERT( CONDITION )  if (!assert_(__FILE__, __LINE__, (CONDITION))) return
@@ -306,7 +318,7 @@ class TestFixture : public ErrorLogger {
 #define TODO_ASSERT( CONDITION ) do { const bool condition=(CONDITION); todoAssertEquals(__FILE__, __LINE__, true, false, condition); } while (false)
 #define TODO_ASSERT_EQUALS( WANTED, CURRENT, ACTUAL ) todoAssertEquals(__FILE__, __LINE__, WANTED, CURRENT, ACTUAL)
 #define EXPECT_EQ( EXPECTED, ACTUAL ) assertEquals(__FILE__, __LINE__, EXPECTED, ACTUAL)
-#define REGISTER_TEST( CLASSNAME ) namespace { CLASSNAME instance_ ## CLASSNAME; }
+#define REGISTER_TEST( CLASSNAME ) namespace { class CLASSNAME ## Instance : public TestInstance { public: CLASSNAME ## Instance() : TestInstance(#CLASSNAME) {} TestFixture* create() override { impl.reset(new CLASSNAME); return impl.get(); } }; CLASSNAME ## Instance instance_ ## CLASSNAME; }
 
 #define PLATFORM( P, T ) do { std::string errstr; assertEquals(__FILE__, __LINE__, true, P.set(Platform::toString(T), errstr, {exename}), errstr); } while (false)
 

test/testmemleak.cpp

@@ -27,7 +27,7 @@
 #include <cstddef>
 #include <list>
 
-class TestMemleak : private TestFixture {
+class TestMemleak : public TestFixture {
 public:
     TestMemleak() : TestFixture("TestMemleak") {}