Merge pull request #162 from jmestwa-coder/fix/reject-whitespace-only-numeric-input

Reject whitespace-only input in numeric value parsing

Author: Taywee

args.hxx

@@ -3676,11 +3676,15 @@ namespace args
             if (std::is_unsigned<T>::value)
             {
                 const unsigned long long parsed = std::strtoull(begin, &end, 0);
+                if (end == begin)
+                {
+                    return false;
+                }
                 while (end != nullptr && *end != '\0' && std::isspace(static_cast<unsigned char>(*end)))
                 {
                     ++end;
                 }
-                if (end == begin || *end != '\0' || errno == ERANGE || parsed > static_cast<unsigned long long>(std::numeric_limits<T>::max()))
+                if (*end != '\0' || errno == ERANGE || parsed > static_cast<unsigned long long>(std::numeric_limits<T>::max()))
                 {
                     errno = saved_errno;  // Restore errno on error
                     return false;
@@ -3691,11 +3695,15 @@ namespace args
             else
             {
                 const long long parsed = std::strtoll(begin, &end, 0);
+                if (end == begin)
+                {
+                    return false;
+                }
                 while (end != nullptr && *end != '\0' && std::isspace(static_cast<unsigned char>(*end)))
                 {
                     ++end;
                 }
-                if (end == begin || *end != '\0' || errno == ERANGE ||
+                if (*end != '\0' || errno == ERANGE ||
                     parsed < static_cast<long long>(std::numeric_limits<T>::min()) ||
                     parsed > static_cast<long long>(std::numeric_limits<T>::max()))
                 {

test/whitespace_numeric.cxx

@@ -0,0 +1,63 @@
+#include "test_common.hxx"
+#include <args.hxx>
+#include "test_helpers.hxx"
+
+int main()
+{
+    args::ArgumentParser parser("This is a test program.", "This goes after the options.");
+    args::ValueFlag<int> foo(parser, "FOO", "test flag", {'f', "foo"});
+    args::ValueFlag<unsigned int> uid(parser, "UID", "numeric id", {'u', "uid"});
+
+    // Valid inputs
+    {
+        std::vector<std::string> args{"--foo", "123"};
+        parser.ParseArgs(args);
+        test::require(args::get(foo) == 123);
+    }
+    
+    {
+        std::vector<std::string> args{"--foo", " 123"};
+        parser.ParseArgs(args);
+        test::require(args::get(foo) == 123);
+    }
+    
+    {
+        std::vector<std::string> args{"--foo", "123 "};
+        parser.ParseArgs(args);
+        test::require(args::get(foo) == 123);
+    }
+    
+    {
+        std::vector<std::string> args{"--foo", "+123"};
+        parser.ParseArgs(args);
+        test::require(args::get(foo) == 123);
+    }
+
+    {
+        std::vector<std::string> args{"--uid", "0x10"};
+        parser.ParseArgs(args);
+        test::require(args::get(uid) == 16);
+    }
+
+    {
+        std::vector<std::string> args{"--uid", "010"};
+        parser.ParseArgs(args);
+        test::require(args::get(uid) == 8);
+    }
+
+    // Failing inputs
+    test::require_throws_as<args::ParseError>([&] { 
+        std::vector<std::string> args{"--foo", "   "};
+        parser.ParseArgs(args); 
+    });
+    test::require_throws_as<args::ParseError>([&] { 
+        std::vector<std::string> args{"--foo", ""};
+        parser.ParseArgs(args); 
+    });
+    test::require_throws_as<args::ParseError>([&] { 
+        std::vector<std::string> args{"--uid", "   "};
+        parser.ParseArgs(args); 
+    });
+    
+    return 0;
+}