LibTest: Change #define-d constants into constexpr and a runtime flag

MAX_GENERATED_VALUES_PER_TEST is now the --randomized_runs flag:
$ ./Build/lagom/bin/TestGenerator --randomized_runs 1000

It's sometimes useful to try larger numbers for it instead of the
default of 100.

MAX_GEN_ATTEMPTS_PER_VALUE is now a constexpr. It's not usually needed
to tweak this value; we can recompile with a different value on the rare
occasion.

Userland/Libraries/LibTest/Macros.h

@@ -30,6 +30,8 @@ void set_randomness_source(Randomized::RandomnessSource);
 bool is_reporting_enabled();
 void enable_reporting();
 void disable_reporting();
+
+u64 randomized_runs();
 }
 
 #define EXPECT_EQ(a, b)                                                                                       \

Userland/Libraries/LibTest/TestCase.h

@@ -7,22 +7,13 @@
 
 #pragma once
 
-#include <LibTest/Macros.h> // intentionally first -- we redefine VERIFY and friends in here
-#include <LibTest/Randomized/RandomnessSource.h>
-#include <LibTest/Randomized/Shrink.h>
-
 #include <AK/DeprecatedString.h>
 #include <AK/Function.h>
 #include <AK/NonnullRefPtr.h>
 #include <AK/RefCounted.h>
-
-#ifndef MAX_GENERATED_VALUES_PER_TEST
-#    define MAX_GENERATED_VALUES_PER_TEST 100
-#endif
-
-#ifndef MAX_GEN_ATTEMPTS_PER_VALUE
-#    define MAX_GEN_ATTEMPTS_PER_VALUE 15
-#endif
+#include <LibTest/Macros.h>
+#include <LibTest/Randomized/RandomnessSource.h>
+#include <LibTest/Randomized/Shrink.h>
 
 namespace Test {
 
@@ -54,8 +45,12 @@ public:
     static NonnullRefPtr<TestCase> randomized(DeprecatedString const& name, TestFunction&& test_function)
     {
         using namespace Randomized;
+
+        constexpr u8 MAX_GEN_ATTEMPTS_PER_VALUE = 15;
+
         TestFunction test_case_function = [test_function = move(test_function)]() {
-            for (u32 i = 0; i < MAX_GENERATED_VALUES_PER_TEST; ++i) {
+            u64 max_randomized_runs = randomized_runs();
+            for (u64 i = 0; i < max_randomized_runs; ++i) {
                 bool generated_successfully = false;
                 u8 gen_attempt;
                 for (gen_attempt = 0; gen_attempt < MAX_GEN_ATTEMPTS_PER_VALUE && !generated_successfully; ++gen_attempt) {
@@ -100,7 +95,7 @@ public:
                     return;
                 }
             }
-            // MAX_GENERATED_VALUES_PER_TEST values generated, all passed the test.
+            // All randomized_runs() values generated + passed the test.
         };
         return make_ref_counted<TestCase>(name, move(test_case_function), false);
     }

Userland/Libraries/LibTest/TestSuite.cpp

@@ -5,10 +5,9 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <LibTest/Macros.h> // intentionally first -- we redefine VERIFY and friends in here
-
 #include <AK/Function.h>
 #include <LibCore/ArgsParser.h>
+#include <LibTest/Macros.h>
 #include <LibTest/TestResult.h>
 #include <LibTest/TestSuite.h>
 #include <math.h>
@@ -64,6 +63,12 @@ Randomized::RandomnessSource& randomness_source()
     return TestSuite::the().randomness_source();
 }
 
+// Declared in Macros.h
+u64 randomized_runs()
+{
+    return TestSuite::the().randomized_runs();
+}
+
 // Declared in TestCase.h
 void add_test_case_to_suite(NonnullRefPtr<TestCase> const& test_case)
 {
@@ -126,6 +131,7 @@ int TestSuite::main(DeprecatedString const& suite_name, Span<StringView> argumen
     args_parser.add_option(do_tests_only, "Only run tests.", "tests", 0);
     args_parser.add_option(do_benchmarks_only, "Only run benchmarks.", "bench", 0);
     args_parser.add_option(m_benchmark_repetitions, "Number of times to repeat each benchmark (default 1)", "benchmark_repetitions", 0, "N");
+    args_parser.add_option(m_randomized_runs, "Number of times to run each RANDOMIZED_TEST_CASE (default 100)", "randomized_runs", 0, "RUNS");
     args_parser.add_option(do_list_cases, "List available test cases.", "list", 0);
     args_parser.add_positional_argument(search_string, "Only run matching cases.", "pattern", Core::ArgsParser::Required::No);
     args_parser.parse(arguments);

Userland/Libraries/LibTest/TestSuite.h

@@ -7,11 +7,10 @@
 
 #pragma once
 
-#include <LibTest/Macros.h> // intentionally first -- we redefine VERIFY and friends in here
-
 #include <AK/DeprecatedString.h>
 #include <AK/Function.h>
 #include <AK/Vector.h>
+#include <LibTest/Macros.h>
 #include <LibTest/Randomized/RandomnessSource.h>
 #include <LibTest/TestCase.h>
 #include <LibTest/TestResult.h>
@@ -61,6 +60,8 @@ public:
     void enable_reporting() { m_reporting_enabled = true; }
     void disable_reporting() { m_reporting_enabled = false; }
 
+    u64 randomized_runs() { return m_randomized_runs; }
+
 private:
     static TestSuite* s_global;
     Vector<NonnullRefPtr<TestCase>> m_cases;
@@ -68,6 +69,7 @@ private:
     u64 m_benchtime = 0;
     DeprecatedString m_suite_name;
     u64 m_benchmark_repetitions = 1;
+    u64 m_randomized_runs = 100;
     Function<void()> m_setup;
     TestResult m_current_test_result = TestResult::NotRun;
     Randomized::RandomnessSource m_randomness_source = Randomized::RandomnessSource::live();