Fix dialyzer errors

[drozzy]

Currently (July 27, 2021) there are these dialyzer errors. I'm sure some are not important, but I'm placing them here just as a reference.

src/chumak_command.erl
Line 295 Column 1: Function decode_hello_message/2 has no local return
Line 320 Column 1: Function decode_welcome_message/2 has no local return
Line 353 Column 1: Function decode_initiate_message/2 has no local return
Line 408 Column 1: Function decode_curve_ready_message/2 has no local return
Line 430 Column 1: Function decode_curve_message/2 has no local return

src/chumak_curve.erl
Line 141 Column 1: Function receive_command/1 will never be called
Line 191 Column 1: Function send_hello_step/2 will never be called
Line 220 Column 1: Function send_welcome_step/2 will never be called
Line 230 Column 1: Function send_initiate_step/3 will never be called
Line 240 Column 1: Function send_ready_step/3 will never be called
Line 251 Column 1: Function validate_client_curve_data/1 has no local return
Line 261 Column 1: Function validate_server_curve_data/1 has no local return

src/chumak_curve_if.erl
Line 40 Column 1: Function randombytes/1 has no local return
Line 44 Column 9: The variable _ can never match since previous clauses completely covered the type 'none'
Line 50 Column 1: Function box_keypair/0 has no local return
Line 54 Column 9: The pattern 'nacl' can never match the type 'none'
Line 57 Column 9: The variable _ can never match since previous clauses completely covered the type 'none'
Line 71 Column 1: Function box/4 has no local return
Line 75 Column 9: The pattern 'nacl' can never match the type 'none'
Line 78 Column 9: The variable _ can never match since previous clauses completely covered the type 'none'
Line 92 Column 1: Function box_open/4 has no local return
Line 96 Column 9: The pattern 'nacl' can never match the type 'none'
Line 99 Column 9: The variable _ can never match since previous clauses completely covered the type 'none'

src/chumak_dealer.erl
Line 100 Column 13: The pattern {'error', Info} can never match the type 'empty' | {'out',[any()]}

src/chumak_peer.erl
Line 343 Column 9: The pattern {'ok', NewState} can never match the type {'error',{'error',{'invalid_command_before_ready',_}} | {'shutdown','invalid_resource' | {'server_error',_}},#state{step::'ready' | 'waiting_peer' | 'waiting_ready',host::'nil' | string(),port::'nil' | number(),conn_side::'client' | 'server',resource::string(),type::'dealer' | 'pair' | 'pub' | 'pull' | 'push' | 'rep' | 'req' | 'router' | 'sub' | 'xpub' | 'xsub',identity::string(),peer_identity::string(),peer_version::{integer(),integer()},socket::'nil' | port() | {'$inet',atom(),_},decoder::{'decoder','command_ready' | 'initial' | 'message_ready' | 'ready' | 'require_size' | 'waiting_as_server' | 'waiting_filler' | 'waiting_mechanism' | 'waiting_minor_version',integer(),'nil' | binary(),'command_ready' | 'initial' | 'message_ready' | 'nil' | 'ready' | 'require_size' | 'waiting_as_server' | 'waiting_filler' | 'waiting_mechanism' | 'waiting_minor_version','nil' | {_,_},'nil' | {_,_},map(),'curve' | 'nil' | 'null',boolean()},parent_pid::pid(),incoming_queue::'nil' | queue:queue(_),msg_buf::[any()],pub_compatible_layer::boolean(),multi_socket_type::boolean(),as_server::boolean(),mechanism::'curve' | 'null',security_data::#{'client_nonce'=>integer(), 'client_public_transient_key'=>binary(), 'client_secret_transient_key'=>binary(), 'cookie_public_key'=>binary(), 'cookie_secret_key'=>binary(), 'curve_publickey'=>binary(), 'curve_secretkey'=>binary(), 'curve_serverkey'=>binary(), 'mechanism'=>'curve', 'role'=>'client' | 'server', 'server_nonce'=>integer(), 'server_public_transient_key'=>binary(), 'server_secret_transient_key'=>binary()}}}
Line 352 Column 2: Invalid type specification for function chumak_peer:handshake/1. The success typing is (#state{step::'ready' | 'waiting_peer' | 'waiting_ready',host::'nil' | string(),port::'nil' | number(),conn_side::'client' | 'server',resource::string(),type::'dealer' | 'pair' | 'pub' | 'pull' | 'push' | 'rep' | 'req' | 'router' | 'sub' | 'xpub' | 'xsub',identity::string(),peer_identity::string(),peer_version::{integer(),integer()},socket::port() | {'$inet',atom(),_},decoder::{'decoder','ready',integer(),binary(),'command_ready' | 'initial' | 'message_ready' | 'nil' | 'ready' | 'require_size' | 'waiting_as_server' | 'waiting_filler' | 'waiting_mechanism' | 'waiting_minor_version',{'some',integer()},{'some',integer()},#{'client_nonce'=>integer(), 'client_public_transient_key'=>binary(), 'client_secret_transient_key'=>binary(), 'cookie_public_key'=>binary(), 'cookie_secret_key'=>binary(), 'curve_publickey'=>binary(), 'curve_secretkey'=>binary(), 'curve_serverkey'=>binary(), 'mechanism'=>'curve', 'role'=>'client' | 'server', 'server_nonce'=>integer(), 'server_public_transient_key'=>binary(), 'server_secret_transient_key'=>binary()},'curve' | 'nil' | 'null',boolean()},parent_pid::pid(),incoming_queue::'nil' | queue:queue(_),msg_buf::[any()],pub_compatible_layer::boolean(),multi_socket_type::boolean(),as_server::boolean(),mechanism::'curve' | 'null',security_data::#{'client_nonce'=>integer(), 'client_public_transient_key'=>binary(), 'client_secret_transient_key'=>binary(), 'cookie_public_key'=>binary(), 'cookie_secret_key'=>binary(), 'curve_publickey'=>binary(), 'curve_secretkey'=>binary(), 'curve_serverkey'=>binary(), 'mechanism'=>'curve', 'role'=>'client' | 'server', 'server_nonce'=>integer(), 'server_public_transient_key'=>binary(), 'server_secret_transient_key'=>binary()}}) -> {'error',{'error',{'invalid_command_before_ready',_}} | {'shutdown','invalid_resource' | {'server_error',_}},#state{step::'ready' | 'waiting_peer' | 'waiting_ready',host::'nil' | string(),port::'nil' | number(),conn_side::'client' | 'server',resource::string(),type::'dealer' | 'pair' | 'pub' | 'pull' | 'push' | 'rep' | 'req' | 'router' | 'sub' | 'xpub' | 'xsub',identity::string(),peer_identity::string(),peer_version::{integer(),integer()},socket::'nil' | port() | {'$inet',atom(),_},decoder::{'decoder','command_ready' | 'initial' | 'message_ready' | 'ready' | 'require_size' | 'waiting_as_server' | 'waiting_filler' | 'waiting_mechanism' | 'waiting_minor_version',integer(),'nil' | binary(),'command_ready' | 'initial' | 'message_ready' | 'nil' | 'ready' | 'require_size' | 'waiting_as_server' | 'waiting_filler' | 'waiting_mechanism' | 'waiting_minor_version','nil' | {_,_},'nil' | {_,_},map(),'curve' | 'nil' | 'null',boolean()},parent_pid::pid(),incoming_queue::'nil' | queue:queue(_),msg_buf::[any()],pub_compatible_layer::boolean(),multi_socket_type::boolean(),as_server::boolean(),mechanism::'curve' | 'null',security_data::#{'client_nonce'=>integer(), 'client_public_transient_key'=>binary(), 'client_secret_transient_key'=>binary(), 'cookie_public_key'=>binary(), 'cookie_secret_key'=>binary(), 'curve_publickey'=>binary(), 'curve_secretkey'=>binary(), 'curve_serverkey'=>binary(), 'mechanism'=>'curve', 'role'=>'client' | 'server', 'server_nonce'=>integer(), 'server_public_transient_key'=>binary(), 'server_secret_transient_key'=>binary()}}}
Line 392 Column 9: The pattern {'ok', ReadyState} can never match the type {'error',{'error',{'invalid_command_before_ready',_}} | {'shutdown','invalid_resource' | {'server_error',_}},#state{step::'ready' | 'waiting_peer' | 'waiting_ready',host::'nil' | string(),port::'nil' | number(),conn_side::'client' | 'server',resource::string(),type::'dealer' | 'pair' | 'pub' | 'pull' | 'push' | 'rep' | 'req' | 'router' | 'sub' | 'xpub' | 'xsub',identity::string(),peer_identity::string(),peer_version::{integer(),integer()},socket::'nil' | port() | {'$inet',atom(),_},decoder::{'decoder','command_ready' | 'initial' | 'message_ready' | 'ready' | 'require_size' | 'waiting_as_server' | 'waiting_filler' | 'waiting_mechanism' | 'waiting_minor_version',integer(),'nil' | binary(),'command_ready' | 'initial' | 'message_ready' | 'nil' | 'ready' | 'require_size' | 'waiting_as_server' | 'waiting_filler' | 'waiting_mechanism' | 'waiting_minor_version','nil' | {'some',integer()},'nil' | {'some',integer()},#{'client_nonce'=>integer(), 'client_public_transient_key'=>binary(), 'client_secret_transient_key'=>binary(), 'cookie_public_key'=>binary(), 'cookie_secret_key'=>binary(), 'curve_publickey'=>binary(), 'curve_secretkey'=>binary(), 'curve_serverkey'=>binary(), 'mechanism'=>'curve', 'role'=>'client' | 'server', 'server_nonce'=>integer(), 'server_public_transient_key'=>binary(), 'server_secret_transient_key'=>binary()},'curve' | 'nil' | 'null',boolean()},parent_pid::pid(),incoming_queue::'nil' | queue:queue(_),msg_buf::[any()],pub_compatible_layer::boolean(),multi_socket_type::boolean(),as_server::boolean(),mechanism::'curve' | 'null',security_data::#{'client_nonce'=>integer(), 'client_public_transient_key'=>binary(), 'client_secret_transient_key'=>binary(), 'cookie_public_key'=>binary(), 'cookie_secret_key'=>binary(), 'curve_publickey'=>binary(), 'curve_secretkey'=>binary(), 'curve_serverkey'=>binary(), 'mechanism'=>'curve', 'role'=>'client' | 'server', 'server_nonce'=>integer(), 'server_public_transient_key'=>binary(), 'server_secret_transient_key'=>binary()}}}
Line 445 Column 1: Function handle_ready_response2/2 has no local return
Line 460 Column 1: Function validate_peer_socket_type/2 has no local return
Line 466 Column 10: The call PatternModule:'valid_peer_type'(PeerSocketType::atom()) requires that PatternModule is of type atom() not {'error','invalid_socket_type'}
Line 587 Column 1: Function send_invalid_socket_type_error/3 will never be called

src/chumak_protocol.erl
Line 158 Column 1: Function build_hello_frame/1 has no local return
Line 224 Column 1: Function build_welcome_frame/1 has no local return
Line 319 Column 1: Function build_initiate_frame/2 has no local return
Line 395 Column 1: Function build_ready_frame/2 has no local return
Line 673 Column 2: Invalid type specification for function chumak_protocol:encode_more_message/3. The success typing is (binary(),_,_) -> {nonempty_binary(),_}
Line 685 Column 2: Invalid type specification for function chumak_protocol:encode_last_message/3. The success typing is (binary(),_,_) -> {nonempty_binary(),_}

src/chumak_pub.erl
Line 128 Column 9: The pattern {'error', Info} can never match the type 'empty' | {'out',[any()]}

src/chumak_pull.erl
Line 120 Column 9: The pattern {'error', Info} can never match the type 'empty' | {'out',[any()]}

src/chumak_rep.erl
Line 141 Column 9: The pattern {'error', Info} can never match the type 'empty' | {'out',[any()]}

src/chumak_router.erl
Line 108 Column 9: The pattern {'error', Info} can never match the type 'empty' | {'out',[any()]}
Line 125 Column 1: Function terminate_lbs/1 will never be called
Line 131 Column 1: Function terminate_lb/1 will never be called

src/chumak_socket.erl
Line 43 Column 9: The variable ModuleName can never match since previous clauses completely covered the type {'error','invalid_socket_type'}

src/chumak_sub.erl
Line 130 Column 9: The pattern {'error', Info} can never match the type 'empty' | {'out',[any()]}
===> Warnings written to _build/default/24.0.4.dialyzer_warnings
===> Warnings occurred running dialyzer: 45

[filmor]

A few observations:

• The has no local return errors come from building without having a NaCl library set.
• There are quite a few "generic" map() specs instead of specific ones

The PR fixes all issues outside of chumak_curve, I'll have another look at that one.