feat: add credo

Author: SpaceEEC

.credo.exs

@@ -0,0 +1,87 @@
+%{
+  configs: [
+    %{
+      name: "default",
+      files: %{
+        included: ["lib/"],
+        excluded: ["lib/test.ex"]
+      },
+      requires: [],
+      checks: [
+        # Consistency
+        {Credo.Check.Consistency.ExceptionNames},
+        {Credo.Check.Consistency.LineEndings},
+        {Credo.Check.Consistency.MultiAliasImportRequireUse},
+        {Credo.Check.Consistency.ParameterPatternMatching},
+        {Credo.Check.Consistency.SpaceAroundOperators},
+        {Credo.Check.Consistency.SpaceInParentheses},
+        {Credo.Check.Consistency.TabsOrSpaces},
+        # Design
+        {Credo.Check.Design.AliasUsage},
+        {Credo.Check.Design.DuplicatedCode},
+        {Credo.Check.Design.TagFIXME},
+        {Credo.Check.Design.TagTODO, exit_status: 0},
+        # Readability
+        {Credo.Check.Readability.AliasOrder},
+        {Credo.Check.Readability.FunctionNames},
+        {Credo.Check.Readability.LargeNumbers},
+        {Credo.Check.Readability.MaxLineLength},
+        {Credo.Check.Readability.ModuleAttributeNames},
+        {Credo.Check.Readability.ModuleDoc},
+        {Credo.Check.Readability.ModuleNames},
+        {Credo.Check.Readability.ParenthesesOnZeroArityDefs, false},
+        {Credo.Check.Readability.PredicateFunctionNames},
+        {Credo.Check.Readability.PreferImplicitTry, false},
+        {Credo.Check.Readability.PreferUnquotedAtoms},
+        {Credo.Check.Readability.RedundantBlankLines},
+        {Credo.Check.Readability.Semicolons},
+        {Credo.Check.Readability.SinglePipe},
+        {Credo.Check.Readability.SpaceAfterCommas},
+        {Credo.Check.Readability.Specs},
+        {Credo.Check.Readability.StringSigils},
+        {Credo.Check.Readability.TrailingBlankLine},
+        {Credo.Check.Readability.TrailingWhiteSpace},
+        {Credo.Check.Readability.UnnecessaryAliasExpansion},
+        {Credo.Check.Readability.VariableNames},
+        # Refactor
+        {Credo.Check.Refactor.ABCSize},
+        {Credo.Check.Refactor.AppendSingleItem},
+        {Credo.Check.Refactor.CaseTrivialMatches},
+        {Credo.Check.Refactor.CondStatements},
+        {Credo.Check.Refactor.CyclomaticComplexity},
+        {Credo.Check.Refactor.DoubleBooleanNegation},
+        {Credo.Check.Refactor.FunctionArity},
+        {Credo.Check.Refactor.LongQuoteBlocks},
+        {Credo.Check.Refactor.MapInto},
+        {Credo.Check.Refactor.MatchInCondition},
+        {Credo.Check.Refactor.ModuleDependencies},
+        {Credo.Check.Refactor.NegatedConditionsInUnless},
+        {Credo.Check.Refactor.NegatedConditionsWithElse},
+        {Credo.Check.Refactor.Nesting},
+        {Credo.Check.Refactor.PerceivedComplexity},
+        {Credo.Check.Refactor.PipeChainStart},
+        {Credo.Check.Refactor.UnlessWithElse},
+        {Credo.Check.Refactor.VariableRebinding, false},
+        # Warning
+        {Credo.Check.Warning.BoolOperationOnSameValues},
+        {Credo.Check.Warning.ExpensiveEmptyEnumCheck},
+        {Credo.Check.Warning.IExPry},
+        {Credo.Check.Warning.IoInspect},
+        {Credo.Check.Warning.LazyLogging},
+        {Credo.Check.Warning.MapGetUnsafePass},
+        {Credo.Check.Warning.OperationOnSameValues},
+        {Credo.Check.Warning.OperationWithConstantResult},
+        {Credo.Check.Warning.RaiseInsideRescue},
+        {Credo.Check.Warning.UnsafeToAtom, false},
+        {Credo.Check.Warning.UnusedEnumOperation},
+        {Credo.Check.Warning.UnusedFileOperation},
+        {Credo.Check.Warning.UnusedKeywordOperation},
+        {Credo.Check.Warning.UnusedListOperation},
+        {Credo.Check.Warning.UnusedPathOperation},
+        {Credo.Check.Warning.UnusedRegexOperation},
+        {Credo.Check.Warning.UnusedStringOperation},
+        {Credo.Check.Warning.UnusedTupleOperation}
+      ]
+    }
+  ]
+}

.gitignore

@@ -22,3 +22,8 @@ erl_crash.dump
 # Ignore package tarball (built via "mix hex.build").
 crux_gateway-*.tar
 
+# VS Code plugin
+.elixir_ls/
+
+# Test file
+lib/test.ex

config/config.exs

@@ -1,15 +1 @@
 use Mix.Config
-
-# Everything may be set / overriden via `Crux.Gateway.start/1´.
-# See documentation of the `Crux.Gateway` module.
-# config :crux_gateway,
-#    # required
-#    token: "your token",
-#    # required, fetch via /gateway/bot
-#    shard_count: 5,
-#    # required, fetch via /gateway(/bot)
-#    url: "wss://gateway.discord.gg",
-#    # optional
-#    shards: [1, 2, 3..5]
-#    # optional
-#    dispatcher: GenStage.BroadcastDispatcher

lib/gateway.ex

@@ -73,12 +73,14 @@ defmodule Crux.Gateway do
           | list()
 
   @doc false
+  @spec init(term()) :: {:ok, tuple()}
   def init(opts) when is_list(opts), do: opts |> Map.new() |> init()
 
   def init(opts) do
-    gateway_opts = transform_opts(opts)
-
-    gateway_opts = Map.put(gateway_opts, :gateway, self())
+    gateway_opts =
+      opts
+      |> transform_opts()
+      |> Map.put(gateway_opts, :gateway, self())
 
     shards =
       for shard_id <- gateway_opts.shards do
@@ -158,29 +160,24 @@ defmodule Crux.Gateway do
           Map.put(opts, :shards, Enum.to_list(0..(shard_count - 1)))
       end
 
-    case opts do
-      %{presence: %{}} ->
-        nil
-
-      %{presence: p} when is_function(p, 1) ->
-        nil
-
-      %{presence: nil} ->
-        nil
+    if Map.has_key?(opts, :presence) do
+      raise_invalid_presence(opts.presence)
+    end
 
-      %{presence: other} ->
-        raise """
-        :presence is not of the correct type.
+    opts
+  end
 
-        Received:
-        #{inspect(other)}
-        """
+  defp raise_invalid_presence(%{}), do: nil
+  defp raise_invalid_presence(p) when is_function(p, 1), do: nil
+  defp raise_invalid_presence(nil), do: nil
 
-      _ ->
-        nil
-    end
+  defp raise_invald_presence(other) do
+    raise """
+    :presence is not of the correct type.
 
-    opts
+    Received:
+    #{inspect(other)}
+    """
   end
 
   defp map_shard(num, _shards) when is_number(num), do: [num]

lib/gateway/command.ex

@@ -1,4 +1,6 @@
 defmodule Crux.Gateway.Command do
+  # credo:disable-for-this-file Credo.Check.Readability.SinglePipe
+
   @moduledoc """
   Builds [Gateway Commands](https://discordapp.com/developers/docs/topics/gateway#commands-and-events-gateway-commands).
   Note: Only the sent ones can be found here.
@@ -56,7 +58,8 @@ defmodule Crux.Gateway.Command do
 
   def identify(%{shard_id: shard_id, shard_count: shard_count, token: token} = args) do
     presence =
-      case args do
+      args
+      |> case do
         %{presence: presence} when is_map(presence) ->
           presence
 

lib/gateway/connection/connection.ex

@@ -3,8 +3,8 @@ defmodule Crux.Gateway.Connection do
     Module handling the actual connection (shard) to Discord.
   """
   alias Crux.Gateway
-  alias Crux.Gateway.{Connection, Command, IdentifyLimiter, Util}
-  alias Crux.Gateway.Connection.{RateLimiter, Producer}
+  alias Crux.Gateway.{Command, Connection, IdentifyLimiter, Util}
+  alias Crux.Gateway.Connection.{Producer, RateLimiter}
 
   use WebSockex
 
@@ -64,6 +64,7 @@ defmodule Crux.Gateway.Connection do
   end
 
   @doc false
+  @spec handle_connect(term(), term()) :: term()
   def handle_connect(con, [%{shard_id: shard_id} = args]) do
     Logger.info(fn -> "[Crux][Gateway][Shard #{shard_id}]: Connected" end)
 
@@ -100,6 +101,7 @@ defmodule Crux.Gateway.Connection do
     {:ok, state}
   end
 
+  @spec handle_disconnect(term(), term()) :: term()
   def handle_disconnect(reason, %{hello_timeout: ref} = state) do
     if ref do
       :timer.cancel(ref)
@@ -176,6 +178,7 @@ defmodule Crux.Gateway.Connection do
   end
 
   @doc false
+  @spec handle_info(term(), term()) :: term()
   def handle_info(:stop, state), do: {:close, {1000, "Closing connection"}, state}
   def handle_info({:send, frame}, state), do: {:reply, frame, state}
 
@@ -204,6 +207,7 @@ defmodule Crux.Gateway.Connection do
     {:close, {4000, @hello_timeout_message}, state}
   end
 
+  @spec handle_info(term(), term()) :: {:ok, term()}
   def handle_info(other, %{shard_id: shard_id} = state) do
     Logger.warn(fn ->
       "[Crux][Gateway][Shard #{shard_id}]: Received unexpected message: #{inspect(other)}"
@@ -213,20 +217,22 @@ defmodule Crux.Gateway.Connection do
   end
 
   @doc false
+  @spec terminate(term(), term()) :: nil
   def terminate(reason, %{shard_id: shard_id}) do
     Logger.warn(fn ->
       "[Crux][Gateway][Shard #{shard_id}]: Terminating due to #{inspect(reason)}"
     end)
   end
 
   @doc false
+  @spec handle_frame(term(), term()) :: {:ok, term()}
   def handle_frame({:binary, frame}, %{zlib: {buffer, z}} = state) do
     frame_size = byte_size(frame) - 4
     <<_data::binary-size(frame_size), suffix::binary>> = frame
 
     buffer = buffer <> frame
 
-    {buffer, packet} =
+    {new_buffer, packet} =
       if suffix == <<0, 0, 255, 255>> do
         uncompressed =
           buffer
@@ -249,7 +255,7 @@ defmodule Crux.Gateway.Connection do
         state
       end
 
-    state = %{state | zlib: {buffer, z}}
+    state = %{state | zlib: {new_buffer, z}}
 
     {:ok, state}
   end
@@ -275,7 +281,7 @@ defmodule Crux.Gateway.Connection do
          } = packet
        ) do
     Logger.info(fn ->
-      "[Crux][Gateway][Shard #{shard_id}]: Ready #{packet.d._trace |> Enum.join(" -> ")}"
+      "[Crux][Gateway][Shard #{shard_id}]: Ready #{Enum.join(packet.d._trace, " -> ")}"
     end)
 
     Producer.dispatch(sup, packet, shard_id)

lib/gateway/connection/producer.ex

@@ -37,6 +37,7 @@ defmodule Crux.Gateway.Connection.Producer do
   end
 
   @doc false
+  @spec init(term()) :: {:ok, tuple()}
   def init(dispatcher) do
     state = {
       :queue.new(),
@@ -48,13 +49,15 @@ defmodule Crux.Gateway.Connection.Producer do
   end
 
   @doc false
+  @spec handle_cast(term(), term()) :: {:noreply, list(), term()}
   def handle_cast({:dispatch, event}, {queue, demand}) do
     event
     |> :queue.in(queue)
     |> dispatch_events(demand, [])
   end
 
   @doc false
+  @spec handle_demand(term(), term()) :: {:noreply, list(), term()}
   def handle_demand(incoming_demand, {queue, demand}) do
     dispatch_events(queue, incoming_demand + demand, [])
   end

lib/gateway/connection/rate_limiter.ex

@@ -27,6 +27,7 @@ defmodule Crux.Gateway.Connection.RateLimiter do
   end
 
   @doc false
+  @spec init(term()) :: {:ok, tuple()}
   def init(_args) do
     state = %{
       remaining: @limit,
@@ -37,6 +38,7 @@ defmodule Crux.Gateway.Connection.RateLimiter do
   end
 
   @doc false
+  @spec handle_call(term(), GenServer.from(), term()) :: term()
   def handle_call(:queue, from, %{remaining: 0, reset: reset} = state) do
     case reset - :os.system_time(:seconds) do
       reset when reset > 0 ->

lib/gateway/connection/supervisor.ex

@@ -11,10 +11,9 @@ defmodule Crux.Gateway.Connection.Supervisor do
   @spec start_link(args :: term()) :: Supervisor.on_start()
   def start_link(args), do: Supervisor.start_link(__MODULE__, args)
 
+  @spec init(term()) :: {:ok, tuple()}
   def init(args) do
-    args =
-      args
-      |> Map.put(:sup, self())
+    args = Map.put(args, :sup, self())
 
     dispatcher = Map.get(args, :dispatcher, GenStage.BroadcastDispatcher)
 

lib/gateway/identify_limiter.ex

@@ -31,6 +31,7 @@ defmodule Crux.Gateway.IdentifyLimiter do
   end
 
   @doc false
+  @spec init(term()) :: {:ok, term()}
   def init(_args) do
     Logger.debug("[Crux][Gateway][IdentifyLimiter]: Starting")
 
@@ -41,6 +42,7 @@ defmodule Crux.Gateway.IdentifyLimiter do
   end
 
   @doc false
+  @spec handle_call(term(), GenServer.from(), term()) :: term()
   def handle_call(:queue, _from, ratelimit_reset) do
     now = :os.system_time(:milli_seconds)
 

mix.exs

@@ -41,7 +41,7 @@ defmodule Crux.Gateway.MixProject do
       {:gen_stage, "~> 0.13.1"},
       {:websockex, "~> 0.4.1"},
       {:poison, "~> 3.1.0"},
-      {:credo, "~> 0.9.2", only: [:dev, :test], runtime: false},
+      {:credo, "~> 1.0.0", only: [:dev, :test], runtime: false},
       {:ex_doc,
        git: "https://github.com/spaceeec/ex_doc",
        branch: "feat/umbrella",

mix.lock

@@ -1,9 +1,10 @@
 %{
   "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm"},
-  "credo": {:hex, :credo, "0.9.3", "76fa3e9e497ab282e0cf64b98a624aa11da702854c52c82db1bf24e54ab7c97a", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:poison, ">= 0.0.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
+  "credo": {:hex, :credo, "1.0.4", "d2214d4cc88c07f54004ffd5a2a27408208841be5eca9f5a72ce9e8e835f7ede", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm"},
   "earmark": {:hex, :earmark, "1.2.6", "b6da42b3831458d3ecc57314dff3051b080b9b2be88c2e5aa41cd642a5b044ed", [:mix], [], "hexpm"},
   "ex_doc": {:git, "https://github.com/spaceeec/ex_doc", "ba85b84d56c24a42db725858b07f7b2cdc4a37b7", [branch: "feat/umbrella"]},
   "gen_stage": {:hex, :gen_stage, "0.13.1", "edff5bca9cab22c5d03a834062515e6a1aeeb7665fb44eddae086252e39c4378", [:mix], [], "hexpm"},
+  "jason": {:hex, :jason, "1.1.2", "b03dedea67a99223a2eaf9f1264ce37154564de899fd3d8b9a21b1a6fd64afe7", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
   "makeup": {:hex, :makeup, "0.8.0", "9cf32aea71c7fe0a4b2e9246c2c4978f9070257e5c9ce6d4a28ec450a839b55f", [:mix], [{:nimble_parsec, "~> 0.5.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm"},
   "makeup_elixir": {:hex, :makeup_elixir, "0.13.0", "be7a477997dcac2e48a9d695ec730b2d22418292675c75aa2d34ba0909dcdeda", [:mix], [{:makeup, "~> 0.8", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm"},
   "nimble_parsec": {:hex, :nimble_parsec, "0.5.0", "90e2eca3d0266e5c53f8fbe0079694740b9c91b6747f2b7e3c5d21966bba8300", [:mix], [], "hexpm"},