refactor: Add util_CheckValue test

Test GetSetting and GetArg type coercion, negation, and default value handling.
Test is expanded later to cover other flags besides ALLOW_ANY when they are
implemented in bitcoin#16545

This commit does not change behavior.

src/test/util_tests.cpp

@@ -5,6 +5,7 @@
 #include <util/system.h>
 
 #include <clientversion.h>
+#include <optional.h>
 #include <sync.h>
 #include <test/util/setup_common.h>
 #include <test/util.h>
@@ -189,12 +190,119 @@ struct TestArgsManager : public ArgsManager
             AddArg(arg.first, "", arg.second, OptionsCategory::OPTIONS);
         }
     }
+    using ArgsManager::GetSetting;
+    using ArgsManager::GetSettingsList;
     using ArgsManager::ReadConfigStream;
     using ArgsManager::cs_args;
     using ArgsManager::m_network;
     using ArgsManager::m_settings;
 };
 
+//! Test GetSetting and GetArg type coercion, negation, and default value handling.
+class CheckValueTest : public TestChain100Setup
+{
+public:
+    struct Expect {
+        util::SettingsValue setting;
+        bool default_string = false;
+        bool default_int = false;
+        bool default_bool = false;
+        const char* string_value = nullptr;
+        Optional<int64_t> int_value;
+        Optional<bool> bool_value;
+        Optional<std::vector<std::string>> list_value;
+        const char* error = nullptr;
+
+        Expect(util::SettingsValue s) : setting(std::move(s)) {}
+        Expect& DefaultString() { default_string = true; return *this; }
+        Expect& DefaultInt() { default_int = true; return *this; }
+        Expect& DefaultBool() { default_bool = true; return *this; }
+        Expect& String(const char* s) { string_value = s; return *this; }
+        Expect& Int(int64_t i) { int_value = i; return *this; }
+        Expect& Bool(bool b) { bool_value = b; return *this; }
+        Expect& List(std::vector<std::string> m) { list_value = std::move(m); return *this; }
+        Expect& Error(const char* e) { error = e; return *this; }
+    };
+
+    void CheckValue(unsigned int flags, const char* arg, const Expect& expect)
+    {
+        TestArgsManager test;
+        test.SetupArgs({{"-value", flags}});
+        const char* argv[] = {"ignored", arg};
+        std::string error;
+        bool success = test.ParseParameters(arg ? 2 : 1, (char**)argv, error);
+
+        BOOST_CHECK_EQUAL(test.GetSetting("-value").write(), expect.setting.write());
+        auto settings_list = test.GetSettingsList("-value");
+        if (expect.setting.isNull() || expect.setting.isFalse()) {
+            BOOST_CHECK_EQUAL(settings_list.size(), 0);
+        } else {
+            BOOST_CHECK_EQUAL(settings_list.size(), 1);
+            BOOST_CHECK_EQUAL(settings_list[0].write(), expect.setting.write());
+        }
+
+        if (expect.error) {
+            BOOST_CHECK(!success);
+            BOOST_CHECK_NE(error.find(expect.error), std::string::npos);
+        } else {
+            BOOST_CHECK(success);
+            BOOST_CHECK_EQUAL(error, "");
+        }
+
+        if (expect.default_string) {
+            BOOST_CHECK_EQUAL(test.GetArg("-value", "zzzzz"), "zzzzz");
+        } else if (expect.string_value) {
+            BOOST_CHECK_EQUAL(test.GetArg("-value", "zzzzz"), expect.string_value);
+        } else {
+            BOOST_CHECK(!success);
+        }
+
+        if (expect.default_int) {
+            BOOST_CHECK_EQUAL(test.GetArg("-value", 99999), 99999);
+        } else if (expect.int_value) {
+            BOOST_CHECK_EQUAL(test.GetArg("-value", 99999), *expect.int_value);
+        } else {
+            BOOST_CHECK(!success);
+        }
+
+        if (expect.default_bool) {
+            BOOST_CHECK_EQUAL(test.GetBoolArg("-value", false), false);
+            BOOST_CHECK_EQUAL(test.GetBoolArg("-value", true), true);
+        } else if (expect.bool_value) {
+            BOOST_CHECK_EQUAL(test.GetBoolArg("-value", false), *expect.bool_value);
+            BOOST_CHECK_EQUAL(test.GetBoolArg("-value", true), *expect.bool_value);
+        } else {
+            BOOST_CHECK(!success);
+        }
+
+        if (expect.list_value) {
+            auto l = test.GetArgs("-value");
+            BOOST_CHECK_EQUAL_COLLECTIONS(l.begin(), l.end(), expect.list_value->begin(), expect.list_value->end());
+        } else {
+            BOOST_CHECK(!success);
+        }
+    }
+};
+
+BOOST_FIXTURE_TEST_CASE(util_CheckValue, CheckValueTest)
+{
+    using M = ArgsManager;
+
+    CheckValue(M::ALLOW_ANY, nullptr, Expect{{}}.DefaultString().DefaultInt().DefaultBool().List({}));
+    CheckValue(M::ALLOW_ANY, "-novalue", Expect{false}.String("0").Int(0).Bool(false).List({}));
+    CheckValue(M::ALLOW_ANY, "-novalue=", Expect{false}.String("0").Int(0).Bool(false).List({}));
+    CheckValue(M::ALLOW_ANY, "-novalue=0", Expect{true}.String("1").Int(1).Bool(true).List({"1"}));
+    CheckValue(M::ALLOW_ANY, "-novalue=1", Expect{false}.String("0").Int(0).Bool(false).List({}));
+    CheckValue(M::ALLOW_ANY, "-novalue=2", Expect{false}.String("0").Int(0).Bool(false).List({}));
+    CheckValue(M::ALLOW_ANY, "-novalue=abc", Expect{true}.String("1").Int(1).Bool(true).List({"1"}));
+    CheckValue(M::ALLOW_ANY, "-value", Expect{""}.String("").Int(0).Bool(true).List({""}));
+    CheckValue(M::ALLOW_ANY, "-value=", Expect{""}.String("").Int(0).Bool(true).List({""}));
+    CheckValue(M::ALLOW_ANY, "-value=0", Expect{"0"}.String("0").Int(0).Bool(false).List({"0"}));
+    CheckValue(M::ALLOW_ANY, "-value=1", Expect{"1"}.String("1").Int(1).Bool(true).List({"1"}));
+    CheckValue(M::ALLOW_ANY, "-value=2", Expect{"2"}.String("2").Int(2).Bool(true).List({"2"}));
+    CheckValue(M::ALLOW_ANY, "-value=abc", Expect{"abc"}.String("abc").Int(0).Bool(false).List({"abc"}));
+}
+
 BOOST_AUTO_TEST_CASE(util_ParseParameters)
 {
     TestArgsManager testArgs;