Fix compilation warnings & housekeeping

.circleci/config.yml

@@ -1,8 +1,17 @@
-version: 2.0
+version: 2.1
+commands:
+  restore_mix_cache:
+    steps:
+      - restore_cache:
+          keys:
+            - mix-cache-{{ arch }}-{{ .Branch }}-{{ checksum "mix.lock" }}
+            - mix-cache-{{ arch }}-{{ .Branch }}
+            - mix-cache-{{ arch }}
+
 jobs:
-  build:
+  test:
     docker:
-      - image: circleci/elixir:1.9.4
+      - image: cimg/elixir:1.13
         environment:
           MIX_ENV: test
 
@@ -11,8 +20,43 @@ jobs:
     steps:
       - checkout
       - run: mix local.hex --force
+      - restore_mix_cache
       - run: mix deps.get
-      - run: mix format --check-formatted
       - run: mix compile --force --warnings-as-errors
+      - save_cache:
+          key: mix-cache-{{ arch }}-{{ .Branch }}-{{ checksum "mix.lock" }}
+          paths: ["deps", "_build"]
       - run: mix test
-      - run: MIX_ENV=dev mix docs && ! mix docs 2>&1 | grep -q "warning:"
+
+  lint:
+    docker:
+      - image: cimg/elixir:1.13
+        environment:
+          MIX_ENV: dev
+
+    working_directory: ~/app
+
+    steps:
+      - checkout
+      - run: mix local.hex --force
+      - restore_mix_cache
+      - run: mix deps.get
+      - run: mix format --check-formatted
+      - run: mix compile
+      - run: mix credo
+      - run: mix docs && mix docs 2>&1 | (! grep -q "warning:")
+      - run: elixir -v | tail -n 1 > .elixir_version
+      - restore_cache:
+          keys:
+            - dialyzer-cache-{{ arch }}-{{ checksum ".elixir_version" }}
+      - run: mix dialyzer
+      - save_cache:
+          key: dialyzer-cache-{{ arch }}-{{ checksum ".elixir_version" }}
+          paths: "priv/plts"
+
+workflows:
+  version: 2
+  build:
+    jobs:
+      - test
+      - lint

.credo.exs

@@ -0,0 +1,187 @@
+# This file contains the configuration for Credo and you are probably reading
+# this after creating it with `mix credo.gen.config`.
+#
+# If you find anything wrong or unclear in this file, please report an
+# issue on GitHub: https://github.com/rrrene/credo/issues
+#
+%{
+  #
+  # You can have as many configs as you like in the `configs:` field.
+  configs: [
+    %{
+      #
+      # Run any config using `mix credo -C <name>`. If no config name is given
+      # "default" is used.
+      #
+      name: "default",
+      #
+      # These are the files included in the analysis:
+      files: %{
+        #
+        # You can give explicit globs or simply directories.
+        # In the latter case `**/*.{ex,exs}` will be used.
+        #
+        included: [
+          "lib/",
+          "src/",
+          "test/",
+          "web/",
+          "apps/*/lib/",
+          "apps/*/src/",
+          "apps/*/test/",
+          "apps/*/web/"
+        ],
+        excluded: [~r"/_build/", ~r"/deps/", ~r"/node_modules/"]
+      },
+      #
+      # Load and configure plugins here:
+      #
+      plugins: [],
+      #
+      # If you create your own checks, you must specify the source files for
+      # them here, so they can be loaded by Credo before running the analysis.
+      #
+      requires: [],
+      #
+      # If you want to enforce a style guide and need a more traditional linting
+      # experience, you can change `strict` to `true` below:
+      #
+      strict: false,
+      #
+      # To modify the timeout for parsing files, change this value:
+      #
+      parse_timeout: 5000,
+      #
+      # If you want to use uncolored output by default, you can change `color`
+      # to `false` below:
+      #
+      color: true,
+      #
+      # You can customize the parameters of any check by adding a second element
+      # to the tuple.
+      #
+      # To disable a check put `false` as second element:
+      #
+      #     {Credo.Check.Design.DuplicatedCode, false}
+      #
+      checks: [
+        #
+        ## Consistency Checks
+        #
+        {Credo.Check.Consistency.ExceptionNames, []},
+        {Credo.Check.Consistency.LineEndings, []},
+        {Credo.Check.Consistency.ParameterPatternMatching, []},
+        {Credo.Check.Consistency.SpaceAroundOperators, []},
+        {Credo.Check.Consistency.SpaceInParentheses, []},
+        {Credo.Check.Consistency.TabsOrSpaces, []},
+
+        #
+        ## Design Checks
+        #
+        # You can customize the priority of any check
+        # Priority values are: `low, normal, high, higher`
+        #
+        {Credo.Check.Design.AliasUsage,
+         [priority: :low, if_nested_deeper_than: 2, if_called_more_often_than: 0]},
+        # You can also customize the exit_status of each check.
+        # If you don't want TODO comments to cause `mix credo` to fail, just
+        # set this value to 0 (zero).
+        #
+        {Credo.Check.Design.TagTODO, [exit_status: 0]},
+        {Credo.Check.Design.TagFIXME, []},
+
+        #
+        ## Readability Checks
+        #
+        {Credo.Check.Readability.AliasOrder, []},
+        {Credo.Check.Readability.FunctionNames, []},
+        {Credo.Check.Readability.LargeNumbers, []},
+        {Credo.Check.Readability.MaxLineLength, [priority: :low, max_length: 120]},
+        {Credo.Check.Readability.ModuleAttributeNames, []},
+        {Credo.Check.Readability.ModuleDoc, []},
+        {Credo.Check.Readability.ModuleNames, []},
+        {Credo.Check.Readability.ParenthesesInCondition, []},
+        {Credo.Check.Readability.ParenthesesOnZeroArityDefs, parens: true},
+        {Credo.Check.Readability.PredicateFunctionNames, []},
+        {Credo.Check.Readability.PreferImplicitTry, []},
+        {Credo.Check.Readability.RedundantBlankLines, []},
+        {Credo.Check.Readability.Semicolons, []},
+        {Credo.Check.Readability.SpaceAfterCommas, []},
+        {Credo.Check.Readability.StringSigils, []},
+        {Credo.Check.Readability.TrailingBlankLine, []},
+        {Credo.Check.Readability.TrailingWhiteSpace, []},
+        {Credo.Check.Readability.UnnecessaryAliasExpansion, []},
+        {Credo.Check.Readability.VariableNames, []},
+        {Credo.Check.Readability.WithSingleClause, false},
+
+        #
+        ## Refactoring Opportunities
+        #
+        {Credo.Check.Refactor.CondStatements, []},
+        {Credo.Check.Refactor.CyclomaticComplexity, []},
+        {Credo.Check.Refactor.FunctionArity, []},
+        {Credo.Check.Refactor.LongQuoteBlocks, []},
+        {Credo.Check.Refactor.MapInto, false},
+        {Credo.Check.Refactor.MatchInCondition, []},
+        {Credo.Check.Refactor.NegatedConditionsInUnless, []},
+        {Credo.Check.Refactor.NegatedConditionsWithElse, []},
+        {Credo.Check.Refactor.Nesting, []},
+        {Credo.Check.Refactor.UnlessWithElse, []},
+        {Credo.Check.Refactor.WithClauses, []},
+
+        #
+        ## Warnings
+        #
+        {Credo.Check.Warning.BoolOperationOnSameValues, []},
+        {Credo.Check.Warning.ExpensiveEmptyEnumCheck, []},
+        {Credo.Check.Warning.IExPry, []},
+        {Credo.Check.Warning.IoInspect, []},
+        {Credo.Check.Warning.LazyLogging, false},
+        {Credo.Check.Warning.MixEnv, []},
+        {Credo.Check.Warning.OperationOnSameValues, []},
+        {Credo.Check.Warning.OperationWithConstantResult, []},
+        {Credo.Check.Warning.RaiseInsideRescue, []},
+        {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, []},
+        {Credo.Check.Warning.UnsafeExec, []},
+
+        #
+        # Checks scheduled for next check update (opt-in for now, just replace `false` with `[]`)
+
+        #
+        # Controversial and experimental checks (opt-in, just replace `false` with `[]`)
+        #
+        {Credo.Check.Readability.StrictModuleLayout,
+         priority: :normal, order: ~w/shortdoc moduledoc behaviour use import require alias/a},
+        {Credo.Check.Consistency.MultiAliasImportRequireUse, false},
+        {Credo.Check.Consistency.UnusedVariableNames, force: :meaningful},
+        {Credo.Check.Design.DuplicatedCode, false},
+        {Credo.Check.Readability.AliasAs, false},
+        {Credo.Check.Readability.MultiAlias, false},
+        {Credo.Check.Readability.Specs, []},
+        {Credo.Check.Readability.SinglePipe, false},
+        {Credo.Check.Readability.WithCustomTaggedTuple, false},
+        {Credo.Check.Refactor.ABCSize, false},
+        {Credo.Check.Refactor.AppendSingleItem, false},
+        {Credo.Check.Refactor.DoubleBooleanNegation, false},
+        {Credo.Check.Refactor.ModuleDependencies, false},
+        {Credo.Check.Refactor.NegatedIsNil, false},
+        {Credo.Check.Refactor.PipeChainStart, false},
+        {Credo.Check.Refactor.VariableRebinding, false},
+        {Credo.Check.Warning.LeakyEnvironment, false},
+        {Credo.Check.Warning.MapGetUnsafePass, false},
+        {Credo.Check.Warning.UnsafeToAtom, false}
+
+        #
+        # Custom checks can be created using `mix credo.gen.check`.
+        #
+      ]
+    }
+  ]
+}

lib/bunch.ex

@@ -272,8 +272,7 @@ defmodule Bunch do
       [nil]
 
   """
-  @spec listify(l) :: l when l: list
-  @spec listify(a) :: [a] when a: any
+  @spec listify(a | [a]) :: [a] when a: any
   def listify(list) when is_list(list) do
     list
   end
@@ -297,7 +296,7 @@ defmodule Bunch do
   @spec error_if_nil(value, reason) :: Type.try_t(value)
         when value: any(), reason: any()
   def error_if_nil(nil, reason), do: {:error, reason}
-  def error_if_nil(v, _), do: {:ok, v}
+  def error_if_nil(v, _reason), do: {:ok, v}
 
   @doc """
   Returns given stateful try value along with its status.
@@ -359,7 +358,7 @@ defmodule Bunch do
         {:&, _meta, [i]} = node, acc when is_integer(i) ->
           {node, acc}
 
-        {:&, meta, _}, _acc ->
+        {:&, meta, _args}, _acc ->
           """
           The `&` (capture) operator is not allowed in lambda-like version of \
           `#{inspect(__MODULE__)}.~>/2`. Use `&1` alone instead.
@@ -418,6 +417,8 @@ defmodule Bunch do
     |> raise_compile_error(__CALLER__)
   end
 
+  @spec raise_compile_error(term(), Macro.Env.t(), Keyword.t()) :: no_return()
+  @spec raise_compile_error(term(), Macro.Env.t()) :: no_return()
   defp raise_compile_error(reason, caller, meta \\ []) do
     raise CompileError,
       file: caller.file,

lib/bunch/access.ex

@@ -3,9 +3,11 @@ defmodule Bunch.Access do
   A bunch of functions for easier manipulation on terms of types implementing `Access`
   behaviour.
   """
-  import Kernel, except: [get_in: 2, put_in: 2, update_in: 3, get_and_update_in: 3, pop_in: 2]
+
   use Bunch
 
+  import Kernel, except: [get_in: 2, put_in: 2, update_in: 3, get_and_update_in: 3, pop_in: 2]
+
   @compile {:inline, map_keys: 1}
 
   @gen_common_docs fn fun_name ->

lib/bunch/config.ex

@@ -3,9 +3,10 @@ defmodule Bunch.Config do
   A bunch of helpers for parsing and validating configurations.
   """
 
-  alias Bunch.Type
   use Bunch
 
+  alias Bunch.Type
+
   @doc """
   Parses `config` according to `fields_specs`.
 
@@ -117,7 +118,7 @@ defmodule Bunch.Config do
   end
 
   defp parse_field(key, spec, {:ok, value}, config) do
-    validate = spec |> Map.get(:validate, fn _ -> :ok end)
+    validate = spec |> Map.get(:validate, fn _value -> :ok end)
     in_enum = spec |> Map.get(:in, [value])
 
     withl fun:

lib/bunch/macro.ex

@@ -36,7 +36,7 @@ defmodule Bunch.Macro do
   defp replace_call(ast_node, {module, fun_name})
        when is_atom(module) and is_atom(fun_name) do
     case ast_node do
-      {^fun_name, _, args} ->
+      {^fun_name, _ctx, args} ->
         quote do
           apply(unquote(module), unquote(fun_name), unquote(args))
         end
@@ -130,5 +130,6 @@ defmodule Bunch.Macro do
   This function uses `Macro.expand/2` under the hood. Check
   it out for more information and examples.
   """
+  @spec expand_deep(Macro.t(), Macro.Env.t()) :: Macro.t()
   def expand_deep(ast, env), do: Macro.prewalk(ast, fn tree -> Macro.expand(tree, env) end)
 end

lib/bunch/short_ref.ex

@@ -40,7 +40,7 @@ defmodule Bunch.ShortRef do
   @spec new(reference) :: t
   def new(ref \\ make_ref()) do
     ref_list = :erlang.ref_to_list(ref)
-    <<bin_hash_part::binary-size(4), _::binary>> = :crypto.hash(:sha, ref_list)
+    <<bin_hash_part::binary-size(4), _dropped::binary>> = :crypto.hash(:sha, ref_list)
     hash = "#" <> Base.encode16(bin_hash_part, case: :lower)
     %__MODULE__{ref: ref, hash: hash}
   end

lib/bunch/struct.ex

@@ -2,9 +2,11 @@ defmodule Bunch.Struct do
   @moduledoc """
   A bunch of functions for easier manipulation on structs.
   """
-  import Kernel, except: [get_in: 2, put_in: 2, update_in: 3, get_and_update_in: 3, pop_in: 2]
+
   use Bunch
 
+  import Kernel, except: [get_in: 2, put_in: 2, update_in: 3, get_and_update_in: 3, pop_in: 2]
+
   @compile {:inline, map_keys: 1}
 
   @gen_common_docs fn fun_name ->

lib/bunch/typespec.ex

@@ -26,7 +26,8 @@ defmodule Bunch.Typespec do
       :b
 
   """
-  defmacro @{:list_type, _, [{:"::", _, [{name, _, _} = name_var, list]}]} do
+  # credo:disable-for-next-line Credo.Check.Consistency.UnusedVariableNames
+  defmacro @{:list_type, _, [{:"::", _, [{name, _, _env} = name_var, list]}]} do
     type = list |> Enum.reduce(fn a, b -> {:|, [], [a, b]} end)
 
     quote do