Specialize ConfigOption for bool to accept "truthy" / "falsy" values

llarp/config/definition.cpp

@@ -16,6 +16,18 @@ namespace llarp
   {
   }
 
+  template <>
+  bool
+  OptionDefinition<bool>::fromString(const std::string& input)
+  {
+    if (input == "false" || input == "off" || input == "0" || input == "no")
+      return false;
+    else if (input == "true" || input == "on" || input == "1" || input == "yes")
+      return true;
+    else
+      throw std::invalid_argument(stringify(input, " is not a valid bool"));
+  }
+
   ConfigDefinition&
   ConfigDefinition::defineOption(OptionDefinition_ptr def)
   {

llarp/config/definition.hpp

@@ -168,17 +168,19 @@ namespace llarp
             stringify("duplicate value for ", name, ", previous value: ", parsedValues[0]));
       }
 
+      parsedValues.emplace_back(fromString(input));
+    }
+
+    T
+    fromString(const std::string& input)
+    {
       std::istringstream iss(input);
       T t;
       iss >> t;
       if (iss.fail())
-      {
         throw std::invalid_argument(stringify(input, " is not a valid ", typeid(T).name()));
-      }
       else
-      {
-        parsedValues.emplace_back(std::move(t));
-      }
+        return t;
     }
 
     std::string
@@ -239,6 +241,12 @@ namespace llarp
     std::function<void(T)> acceptor;
   };
 
+  /// Specialization for bool types. We don't want to use stringstream parsing in this
+  /// case because we want to accept "truthy" and "falsy" string values (e.g. "off" == false)
+  template <>
+  bool
+  OptionDefinition<bool>::fromString(const std::string& input);
+
   using UndeclaredValueHandler =
       std::function<void(string_view section, string_view name, string_view value)>;
 

test/config/test_llarp_config_definition.cpp

@@ -387,3 +387,19 @@ TEST_CASE("ConfigDefinition [bind]iface regression", "[config regression]")
   CHECK(undeclaredName == "enp35s0");
   CHECK(undeclaredValue == "1091");
 }
+
+TEST_CASE("ConfigDefinition truthy bool values", "[config]")
+{
+  llarp::OptionDefinition<bool> def("foo", "bar", false, true);
+
+  // defaults to true
+  auto maybe = def.getValue();
+  CHECK(maybe.has_value());
+  CHECK(maybe.value() == true);
+
+  // "off" should result in false
+  CHECK_NOTHROW(def.parseValue("off"));
+  maybe = def.getValue();
+  CHECK(maybe.has_value());
+  CHECK(maybe.value() == false);
+}