Improve types and compiler warnings

rebar.config

@@ -1,4 +1,7 @@
-{erl_opts, []}.
+{erl_opts,
+ [warn_missing_doc, warn_missing_spec, warn_unused_import,
+  warn_export_vars, verbose, report, debug_info
+]}.
 
 {deps, [
   {telemetry, "1.3.0"}

src/segmented_cache_helpers.erl

@@ -238,6 +238,7 @@ compare_and_swap(Attempts, EtsSegment, Key, Value, MergerFun) ->
 %% Note that we must first empty the last table, and then rotate the index. If it was done
 %% in the opposite order, there's a chance a worker can insert an entry at the front just
 %% before the table is purged.
+-spec purge_last_segment_and_rotate(segmented_cache:name()) -> non_neg_integer().
 purge_last_segment_and_rotate(Name) ->
     SegmentRecord = get_cache_config(Name),
     Index = atomics:get(SegmentRecord#segmented_cache.index, 1),

src/segmented_cache_server.erl

@@ -10,11 +10,11 @@
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2]).
 
 -type request_content() :: term().
-
 -record(cache_state, {scope :: segmented_cache:scope(),
                       name :: segmented_cache:name(),
                       ttl :: timeout(),
                       timer_ref :: undefined | reference()}).
+-type state() :: #cache_state{}.
 
 %%====================================================================
 %% API
@@ -40,7 +40,7 @@ request_delete_pattern(Name, Pattern) ->
 %% gen_server callbacks
 %%====================================================================
 
--spec init({segmented_cache:name(), segmented_cache:opts()}) -> {ok, #cache_state{}}.
+-spec init({segmented_cache:name(), segmented_cache:opts()}) -> {ok, state()}.
 init({Name, Opts}) ->
     #{scope := Scope, ttl := TTL} = segmented_cache_helpers:init_cache_config(Name, Opts),
     pg:join(Scope, Name, self()),
@@ -52,11 +52,11 @@ init({Name, Opts}) ->
             {ok, #cache_state{scope = Scope, name = Name, ttl = TTL, timer_ref = TimerRef}}
     end.
 
--spec handle_call(any(), gen_server:from(), #cache_state{}) -> {reply, ok, #cache_state{}}.
+-spec handle_call(any(), gen_server:from(), state()) -> {reply, ok, state()}.
 handle_call(_Msg, _From, State) ->
     {reply, ok, State}.
 
--spec handle_cast(term(), #cache_state{}) -> {noreply, #cache_state{}}.
+-spec handle_cast(term(), state()) -> {noreply, state()}.
 handle_cast({delete_entry, Key}, #cache_state{name = Name} = State) ->
     segmented_cache_helpers:delete_entry(Name, Key),
     {noreply, State};
@@ -66,7 +66,7 @@ handle_cast({delete_pattern, Pattern}, #cache_state{name = Name} = State) ->
 handle_cast(_Msg, State) ->
     {noreply, State}.
 
--spec handle_info(any(), #cache_state{}) -> {noreply, #cache_state{}}.
+-spec handle_info(any(), state()) -> {noreply, state()}.
 handle_info(purge, #cache_state{name = Name, ttl = TTL} = State) ->
     segmented_cache_helpers:purge_last_segment_and_rotate(Name),
     case TTL of
@@ -76,6 +76,7 @@ handle_info(purge, #cache_state{name = Name, ttl = TTL} = State) ->
 handle_info(_Msg, State) ->
     {noreply, State}.
 
+-spec terminate(normal | shutdown | {shutdown, term()} | term(), state()) -> term().
 terminate(_Reason, #cache_state{name = Name, timer_ref = TimerRef}) ->
     segmented_cache_helpers:erase_cache_config(Name),
     case TimerRef of