Duplicate symbol WASM compilation error when using header/hpp for contract

Question

I'm looking to use a hpp file as an interface for multiple contracts. I've created a test contract and receiving a WASM compilation error. I based the test contract on the format used by eosio.token.cpp/hpp.

/usr/opt/eosio.cdt/1.6.1/bin/wasm-ld: error: duplicate symbol: testcts::test::testact(eosio::name)

defined in /tmp/test.cpp.o

defined in /tmp/test.cpp.o

test.hpp

#pragma once

#include <eosiolib/eosio.hpp>

using namespace eosio;

namespace testcts {
    class [[eosio::contract("testct")]] test : public contract {
        public:
            test(name receiver, name code, datastream<const char*> ds) : contract(receiver, code, ds) { }

            ACTION testact( name user );
    };
}

test.cpp

#include "test.hpp"

namespace testcts {
    void test::testact( name user ) {
        require_auth( user );
    }
}

Answer 1

For me the error disappears when I use the -o flag to explicitly specify output file:

eosio-cpp -o test.wasm test.cpp