Add parseUInt utility function

There is an increasing number of places where Catch2 wants to parse
strings into numbers, but being stuck in C++14 world, we do not
have good stdlib facilities to do this (`strtoul` and `stoul`
are both bad).

1 files changed, 38 insertions, 0 deletions

diff --git a/tests/SelfTest/IntrospectiveTests/Parse.tests.cpp b/tests/SelfTest/IntrospectiveTests/Parse.tests.cpp
new file mode 100644
index 00000000..99d977b3
--- /dev/null
+++ b/tests/SelfTest/IntrospectiveTests/Parse.tests.cpp
@@ -0,0 +1,38 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE_1_0.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/catch_test_macros.hpp>
+
+#include <catch2/internal/catch_parse_numbers.hpp>
+
+TEST_CASE("Parse uints", "[parse-numbers]") {
+	using Catch::parseUInt;
+	using Catch::Optional;
+
+	SECTION("proper inputs") {
+        REQUIRE( parseUInt( "0" ) == Optional<unsigned int>{ 0 } );
+        REQUIRE( parseUInt( "100" ) == Optional<unsigned int>{ 100 } );
+        REQUIRE( parseUInt( "4294967295" ) ==
+                 Optional<unsigned int>{ 4294967295 } );
+        REQUIRE( parseUInt( "0xFF", 16 ) == Optional<unsigned int>{ 255 } );
+    }
+    SECTION( "Bad inputs" ) {
+        // empty
+        REQUIRE_FALSE( parseUInt( "" ) );
+        // random noise
+        REQUIRE_FALSE( parseUInt( "!!KJHF*#" ) );
+        // negative
+        REQUIRE_FALSE( parseUInt( "-1" ) );
+        // too large
+        REQUIRE_FALSE( parseUInt( "4294967296" ) );
+        REQUIRE_FALSE( parseUInt( "42949672964294967296429496729642949672964294967296" ) );
+        REQUIRE_FALSE( parseUInt( "2 4" ) );
+        // hex with base 10
+        REQUIRE_FALSE( parseUInt( "0xFF", 10 ) );
+    }
+}