test: Add tests for GetArg methods / settings.json type coercion

Just add tests. No changes to application behavior. Tests will be
updated in the next commit changing & improving current behavior.

Include a Qt test for GUI startup crash reported by Rspigler in
https://github.com/bitcoin/bitcoin/issues/24457 caused by GetArg
behavior that happens if settings.json contains an integer value for any
of the configuration options which GUI settings can currently clash with
(-dbcache, -par, -spendzeroconfchange, -signer, -upnp, -natpmp, -listen,
-server, -proxy, -proxy, -onion, -onion, -lang, and -prune).

1 files changed, 112 insertions, 0 deletions

diff --git a/src/test/getarg_tests.cpp b/src/test/getarg_tests.cpp
index 76a65ec528..4dc12ec7d7 100644
--- a/src/test/getarg_tests.cpp
+++ b/src/test/getarg_tests.cpp
@@ -3,6 +3,8 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <test/util/setup_common.h>
+#include <univalue.h>
+#include <util/settings.h>
 #include <util/strencodings.h>
 #include <util/system.h>
 
@@ -41,6 +43,116 @@ void SetupArgs(ArgsManager& local_args, const std::vector<std::pair<std::string,
     }
 }
 
+// Test behavior of GetArg functions when string, integer, and boolean types
+// are specified in the settings.json file. GetArg functions are convenience
+// functions. The GetSetting method can always be used instead of GetArg
+// methods to retrieve original values, and there's not always an objective
+// answer to what GetArg behavior is best in every case. This test makes sure
+// there's test coverage for whatever the current behavior is, so it's not
+// broken or changed unintentionally.
+BOOST_AUTO_TEST_CASE(setting_args)
+{
+    ArgsManager args;
+    SetupArgs(args, {{"-foo", ArgsManager::ALLOW_ANY}});
+
+    auto set_foo = [&](const util::SettingsValue& value) {
+      args.LockSettings([&](util::Settings& settings) {
+        settings.rw_settings["foo"] = value;
+      });
+    };
+
+    set_foo("str");
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "\"str\"");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "str");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 0);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), false);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), false);
+
+    set_foo("99");
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "\"99\"");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "99");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 99);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), true);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), true);
+
+    set_foo("3.25");
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "\"3.25\"");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "3.25");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 3);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), true);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), true);
+
+    set_foo("0");
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "\"0\"");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "0");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 0);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), false);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), false);
+
+    set_foo("");
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "\"\"");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 0);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), true);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), true);
+
+    set_foo(99);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "99");
+    BOOST_CHECK_THROW(args.GetArg("foo", "default"), std::runtime_error);
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 99);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", true), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", false), std::runtime_error);
+
+    set_foo(3.25);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "3.25");
+    BOOST_CHECK_THROW(args.GetArg("foo", "default"), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetIntArg("foo", 100), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", true), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", false), std::runtime_error);
+
+    set_foo(0);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "0");
+    BOOST_CHECK_THROW(args.GetArg("foo", "default"), std::runtime_error);
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 0);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", true), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", false), std::runtime_error);
+
+    set_foo(true);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "true");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "1");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 1);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), true);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), true);
+
+    set_foo(false);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "false");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "0");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 0);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), false);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), false);
+
+    set_foo(UniValue::VOBJ);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "{}");
+    BOOST_CHECK_THROW(args.GetArg("foo", "default"), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetIntArg("foo", 100), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", true), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", false), std::runtime_error);
+
+    set_foo(UniValue::VARR);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "[]");
+    BOOST_CHECK_THROW(args.GetArg("foo", "default"), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetIntArg("foo", 100), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", true), std::runtime_error);
+    BOOST_CHECK_THROW(args.GetBoolArg("foo", false), std::runtime_error);
+
+    set_foo(UniValue::VNULL);
+    BOOST_CHECK_EQUAL(args.GetSetting("foo").write(), "null");
+    BOOST_CHECK_EQUAL(args.GetArg("foo", "default"), "default");
+    BOOST_CHECK_EQUAL(args.GetIntArg("foo", 100), 100);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", true), true);
+    BOOST_CHECK_EQUAL(args.GetBoolArg("foo", false), false);
+}
+
 BOOST_AUTO_TEST_CASE(boolarg)
 {
     ArgsManager local_args;