Bump rebar3_lint to 3.2.3 and either heed or skip its warnings

elvis.config

@@ -13,7 +13,12 @@
                                        locus_util]
                      }},
                      {elvis_style, macro_names, disable},
-                     {elvis_style, no_if_expression, disable}] },
+                     {elvis_style, no_if_expression, disable},
+                     {elvis_style, no_throw, #{
+                            ignore => [locus_custom_fetcher,
+                                       locus_mmdb_data_codec,
+                                       locus_shared_bitarray]
+                     }} ]},
         #{ dirs => ["test/**"],
            filter => "*.erl",
            ruleset => erl_files,

rebar.config

@@ -28,7 +28,7 @@
     {rebar3_ex_doc, "0.2.22"},
     {rebar3_hank, "1.4.0"}, % excluded on OTP 22 (see rebar.config.script)
     {rebar3_hex, "7.0.7"},
-    {rebar3_lint, "1.0.2"}
+    {rebar3_lint, "3.2.3"}
 ]}.
 
 %% == Dialyzer ==

src/locus_cli.erl

@@ -75,10 +75,8 @@ prepare_database(DatabaseURL, LoadTimeout, SuccessHandler) ->
         end,
 
     stderr_println("Loading database from \"~ts\"...", [DatabaseURL]),
-    case locus:start_loader(DatabaseId, DatabaseURL, BaseOpts ++ ExtraOpts) of
-        ok ->
-            wait_for_database_load(DatabaseId, LoadTimeout, SuccessHandler)
-    end.
+    ok = locus:start_loader(DatabaseId, DatabaseURL, BaseOpts ++ ExtraOpts),
+    wait_for_database_load(DatabaseId, LoadTimeout, SuccessHandler).
 
 wait_for_database_load(DatabaseId, LoadTimeout, SuccessHandler) ->
     receive

src/locus_custom_fetcher.erl

@@ -25,6 +25,8 @@
 -module(locus_custom_fetcher).
 -behaviour(gen_server).
 
+-include_lib("stdlib/include/assert.hrl").
+
 %% ------------------------------------------------------------------
 %% Callback Declarations
 %% ------------------------------------------------------------------
@@ -112,7 +114,7 @@
 -type event_load_attempt_dismissed() :: {load_attempt_dismissed, source()}.
 -export_type([event_load_attempt_dismissed/0]).
 
--type source() :: {local|remote, {custom, term()}}.
+-type source() :: {local | remote, {custom, term()}}.
 -export_type([source/0]).
 
 %% ------------------------------------------------------------------
@@ -133,7 +135,8 @@
           args :: term(),
           previous_fetch_metadata :: successful_fetch_metadata() | undefined
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
 
 %% ------------------------------------------------------------------
 %% "Private" API Function Definitions
@@ -153,13 +156,13 @@ source(Module, Args) ->
 -spec description(module(), term()) -> description().
 %% @private
 description(Module, Args) ->
-    case Module:description(Args) of
-        #{database_is_stored_remotely := IsRemote,
-          database_is_fetched_from := _
-         } = Description
-          when is_boolean(IsRemote) ->
-            Description
-    end.
+    #{
+      database_is_stored_remotely := IsRemote,
+      database_is_fetched_from := _
+     } = Description = Module:description(Args),
+
+    ?assertMatch(_ when is_boolean(IsRemote), IsRemote),
+    Description.
 
 -spec start_link(source(), module(), term(), successful_fetch_metadata() | undefined)
         -> {ok, pid()}.

src/locus_database.erl

@@ -127,7 +127,9 @@
           subscribers :: [atom() | pid()],
           subscriber_mons :: #{monitor() => pid()}
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
+
 -type monitor() :: reference().
 
 -record(shared_state, {

src/locus_database_sup.erl

@@ -57,7 +57,7 @@ start_child(Args) ->
     try supervisor:start_child(?SERVER, Args) of
         Result -> Result
     catch
-        exit:{Reason, {gen_server, call, [?SERVER|_]}}
+        exit:{Reason, {gen_server, call, [?SERVER | _]}}
           when Reason =:= noproc;
                Reason =:= normal;
                Reason =:= shutdown;

src/locus_filesystem_load.erl

@@ -75,7 +75,7 @@
 -type event_load_attempt_dismissed() :: {load_attempt_dismissed, source()}.
 -export_type([event_load_attempt_dismissed/0]).
 
--type source() :: {cache|filesystem, path()}.
+-type source() :: {cache | filesystem, path()}.
 -export_type([source/0]).
 
 -type success() ::
@@ -92,7 +92,8 @@
           source :: source(),
           previously_modified_on :: calendar:datetime() | unknown
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
 
 %% ------------------------------------------------------------------
 %% API Function Definitions

src/locus_filesystem_store.erl

@@ -70,7 +70,8 @@
           content :: iodata(),
           modified_on :: calendar:datetime()
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
 
 %% ------------------------------------------------------------------
 %% API Function Definitions

src/locus_http_download.erl

@@ -168,7 +168,8 @@
           response_headers :: headers() | undefined,
           response_body :: iodata() | undefined
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
 
 %% ------------------------------------------------------------------
 %% API Function Definitions
@@ -291,7 +292,7 @@ code_change(_OldVsn, #state{} = State, _Extra) ->
 -spec maybe_censor_url(url(), [opt()]) -> url().
 maybe_censor_url(URL, Opts) ->
     case proplists:get_value(censor_query, Opts, []) of
-        [_|_] = CensoredKeys ->
+        [_ | _] = CensoredKeys ->
             CensoredStringKeys = [atom_to_list(Key) || Key <- CensoredKeys],
             locus_util:censor_url_query(URL, CensoredStringKeys);
         [] ->
@@ -443,7 +444,7 @@ stream_start_redirect_for_location(Permanence, NewLocation, State) ->
     end.
 
 handle_successful_download_conclusion(Headers, Body, State) ->
-    ActualContentLength = integer_to_list( byte_size(Body) ),
+    ActualContentLength = integer_to_list(byte_size(Body)),
 
     case lists:keyfind("content-length", 1, Headers) of
         {_, DeclaredContentLength} when DeclaredContentLength =/= ActualContentLength ->
@@ -505,7 +506,7 @@ cancel_timeout(OptName, State) ->
     end.
 
 cancel_or_flush_timer(Timer, TimeoutMsg) ->
-    is_integer( erlang:cancel_timer(Timer) )
+    is_integer(erlang:cancel_timer(Timer))
     orelse receive
                TimeoutMsg -> true
            after

src/locus_loader.erl

@@ -144,7 +144,8 @@
           cacher_path :: locus_filesystem_store:path() | undefined,
           cacher_source :: source() | undefined
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
 
 -record(settings, {
           update_period :: pos_integer(),
@@ -504,7 +505,7 @@ cached_database_path_for_maxmind_edition_name(Edition, MaybeDate) ->
                 io_lib:format("~ts.~4..0B-~2..0B-~2..0B.mmdb.gz",
                               [BaseFilename, Year, Month, Day])
         end,
-    Filename = [_|_] = unicode:characters_to_list(FilenameChardata),
+    Filename = [_ | _] = unicode:characters_to_list(FilenameChardata),
     filename:join(DirectoryPath, Filename).
 
 -spec cached_database_path_for_url(string()) -> nonempty_string().
@@ -524,7 +525,7 @@ cached_database_path_for_custom_fetcher(Module, FetchedFrom) ->
     SafeModuleName = locus_util:filesystem_safe_name(ModuleName),
     Hash = erlang:phash2(FetchedFrom, 1 bsl 32),
     FilenameChardata = io_lib:format("custom.~ts.~.36..b.mmdb.gz", [SafeModuleName, Hash]),
-    Filename = [_|_] = unicode:characters_to_list(FilenameChardata),
+    Filename = [_ | _] = unicode:characters_to_list(FilenameChardata),
     filename:join(DirectoryPath, Filename).
 
 -spec cache_directory_path() -> nonempty_string().
@@ -967,9 +968,8 @@ fetched_database_modification_datetime({filesystem, _}, #{modified_on := Modific
 
 %-spec make_cached_database_blob(nonempty_string(), binary()) -> binary().
 make_cached_database_blob(CachedTarballPath, EncodedDatabase) ->
-    case filename_extension_parts(CachedTarballPath) of
-        ["gz", "mmdb" | _] -> zlib:gzip(EncodedDatabase)
-    end.
+    ?assertMatch(["gz", "mmdb" | _], filename_extension_parts(CachedTarballPath)),
+    zlib:gzip(EncodedDatabase).
 
 %% ------------------------------------------------------------------
 %% Internal Function Definitions - Monitoring and Events

src/locus_maxmind_download.erl

@@ -102,7 +102,8 @@
           database_download_success :: undefined | locus_http_download:success(),
           checksum_download_pid :: undefined | pid()
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
 
 %% ------------------------------------------------------------------
 %% API Function Definitions

src/locus_mmdb_check.erl

@@ -24,8 +24,6 @@
 %% @doc API for working with MMDB - wholesomeness check
 -module(locus_mmdb_check).
 
--include_lib("stdlib/include/assert.hrl").
-
 %% ------------------------------------------------------------------
 %% API Function Exports
 %% ------------------------------------------------------------------
@@ -187,15 +185,16 @@ validate_data_indices(BitArray, DataSection, Journal) ->
     VisitedBitArray = locus_shared_bitarray:new(byte_size(DataSection)),
     MapKeysBitArray = locus_shared_bitarray:new(byte_size(DataSection)),
 
-    case run_concurrent_tasks(
-           fun (TaskIndex, Concurrency) ->
-                   BatchSize = Concurrency,
-                   BatchOffset = TaskIndex,
-                   validate_data_indices_batch(BitArray, VisitedBitArray, MapKeysBitArray,
-                                               BatchSize, BatchOffset, DataSection,
-                                               Journal)
-           end)
-    of
+    Result = run_concurrent_tasks(
+               fun (TaskIndex, Concurrency) ->
+                       BatchSize = Concurrency,
+                       BatchOffset = TaskIndex,
+                       validate_data_indices_batch(BitArray, VisitedBitArray, MapKeysBitArray,
+                                                   BatchSize, BatchOffset, DataSection,
+                                                   Journal)
+               end),
+
+    case Result of
         {ok, _} ->
             ok;
         {error, _} = Error ->
@@ -223,7 +222,7 @@ spawn_concurrent_tasks(Concurrency, TaskFun) ->
                    || TaskIndex <- lists:seq(0, Concurrency - 1)],
 
     {PidsList, MonitorsList} = lists:unzip(PidMonitors),
-    maps:from_list( lists:zip(MonitorsList, PidsList) ).
+    maps:from_list(lists:zip(MonitorsList, PidsList)).
 
 spawn_task(Fun, TaskIndex, Concurrency) ->
     spawn_monitor(

src/locus_mmdb_data_codec.erl

@@ -794,10 +794,8 @@ validate_array(Aux, Count, RemainingData, Path) ->
 
 validate_array_recur(Aux, Count, RemainingData, Path)
   when Count > 0 ->
-    case validate_array_value(Aux, RemainingData, Path) of
-        {ok, DataAfterValue} ->
-            validate_array_recur(Aux, Count - 1, DataAfterValue, Path)
-    end;
+    {ok, DataAfterValue} = validate_array_value(Aux, RemainingData, Path),
+    validate_array_recur(Aux, Count - 1, DataAfterValue, Path);
 validate_array_recur(_Aux, Count, RemainingData, _Path)
   when Count =:= 0 ->
     {ok, RemainingData}.

src/locus_mmdb_metadata.erl

@@ -103,7 +103,7 @@
          Reason :: parse_or_validation_error().
 parse_and_validate(EncodedDatabase) ->
     case binary:matches(EncodedDatabase, <<?METADATA_MARKER>>) of
-        [_|_] = PossibleMetadataMarkers ->
+        [_ | _] = PossibleMetadataMarkers ->
             {MetadataStart, _} = lists:last(PossibleMetadataMarkers),
             <<TreeAndDataSection:MetadataStart/bytes,
               ?METADATA_MARKER,

src/locus_mmdb_tree.erl

@@ -97,7 +97,7 @@
           walk_manager :: locus_mmdb_tree_walk_manager:handle(),
           journal :: locus_mmdb_check_journal:t(),
           data :: binary(),
-          max_depth :: 128|32
+          max_depth :: 128 | 32
          }).
 
 %% ------------------------------------------------------------------
@@ -111,7 +111,7 @@
     when TreeData :: binary(),
          NodeCount :: non_neg_integer(),
          RecordSize :: non_neg_integer(),
-         IpVersion :: 4|6,
+         IpVersion :: 4 | 6,
          DataSectionSize :: non_neg_integer(),
          Tree :: t(),
          Reason :: term().
@@ -248,7 +248,7 @@ ip_address_to_bitstring({A, B, C, D, E, F, G, H}, Tree) ->
     end.
 
 lookup_bit_address(BitAddress, RootIndex, Tree) ->
-    case lookup_bit_address_recur(BitAddress, _NodeIndex = RootIndex, Tree) of
+    case lookup_bit_address_recur(BitAddress, RootIndex, Tree) of
         {ok, DataIndex} ->
             {ok, DataIndex};
         not_found ->
@@ -334,7 +334,7 @@ bitstring_ip_address_prefix(BitAddress, SuffixSize) when bit_size(BitAddress) =:
 %% ------------------------------------------------------------------
 
 tree_depth_from_path(Path) ->
-    floor( math:log2(Path) ) + 1.
+    floor(math:log2(Path)) + 1.
 
 validate_(NodeIndex, Fun, WalkManager, Journal, Tree, Path, Depth) ->
     Aux = #validation_aux{node_count = Tree#tree.node_count,
@@ -444,7 +444,7 @@ journal_prefix_recur(Path, Aux, Prefix)
                       {A, B, C, D}
               end,
 
-    StringAddress = [_|_] = inet:ntoa(Address),
+    StringAddress = [_ | _] = inet:ntoa(Address),
     StringAddress ++ "/" ++ integer_to_list(PrefixSize).
 
 journal_path(Path, Aux) ->

src/locus_mmdb_tree_walk_manager.erl

@@ -81,7 +81,8 @@
           concurrency :: pos_integer(),
           free_workers :: [{pid(), reply_tag()}]
          }).
--type state() :: #state{}.
+-opaque state() :: #state{}.
+-export_type([state/0]).
 
 -if(?OTP_RELEASE < 25).
 -type reply_tag() :: reference().

src/locus_util.erl

@@ -24,8 +24,6 @@
 %% @private
 -module(locus_util).
 
--include_lib("kernel/include/file.hrl").
-
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
 -endif.
@@ -95,7 +93,7 @@ parse_ip_address(_Invalid) ->
 
 -spec lists_anymap(fun ((term()) -> boolean() | {true, term()}), list())
         -> {true, term()} | false.
-lists_anymap(Fun, [H|T]) ->
+lists_anymap(Fun, [H | T]) ->
     case Fun(H) of
         {true, Mapped} -> {true, Mapped};
         true -> {true, H};
@@ -171,7 +169,7 @@ is_date(Date) ->
     end.
 
 -spec purge_term_of_very_large_binaries(T) -> T.
-purge_term_of_very_large_binaries([H|T]) ->
+purge_term_of_very_large_binaries([H | T]) ->
     MappedH = purge_term_of_very_large_binaries(H),
     MappedT = purge_term_of_very_large_binaries(T),
     [MappedH | MappedT];
@@ -310,17 +308,17 @@ is_termination_reason_harmless(Reason) ->
 %% ------------------------------------------------------------------
 
 -spec lists_take_recur(term(), list(), list()) -> {ok, list()} | error.
-lists_take_recur(Elem, [H|T], Acc) when Elem =:= H ->
+lists_take_recur(Elem, [H | T], Acc) when Elem =:= H ->
     {ok, lists:reverse(Acc, T)};
-lists_take_recur(Elem, [H|T], Acc) ->
-    lists_take_recur(Elem, T, [H|Acc]);
+lists_take_recur(Elem, [H | T], Acc) ->
+    lists_take_recur(Elem, T, [H | Acc]);
 lists_take_recur(_, [], _) ->
     error.
 
 -spec flush_link_exit(pid(), timeout()) -> boolean().
 flush_link_exit(Pid, Timeout) ->
     receive
-        {'EXIT', Pid, _} -> true
+        {'EXIT', P, _} when P =:= Pid -> true
     after
         Timeout -> false
     end.
@@ -334,7 +332,7 @@ url_query_encode_codepoint(Codepoint)
        Codepoint =:= $.;
        Codepoint =:= $_ ->
     <<Codepoint>>;
-url_query_encode_codepoint($\ ) ->
+url_query_encode_codepoint(32) -> % codepoint for `$\ ` which Elvis doesnt like
     <<$+>>;
 url_query_encode_codepoint(Codepoint) ->
     UTF8Bytes = <<Codepoint/utf8>>,