From credo
Configures Credo static analysis for Elixir projects with custom rules for consistency, design, readability, and refactoring checks in .credo.exs files. Useful for tailored code quality enforcement.
How this skill is triggered — by the user, by Claude, or both
Slash command
/credo:credo-configurationThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
Credo is a static code analysis tool for Elixir focused on code quality and consistency.
Credo is a static code analysis tool for Elixir focused on code quality and consistency.
%{
configs: [
%{
name: "default",
strict: true,
color: true,
files: %{
included: ["lib/", "src/", "test/", "web/", "apps/*/lib/", "apps/*/test/"],
excluded: [~r"/_build/", ~r"/deps/", ~r"/node_modules/"]
},
plugins: [],
requires: [],
parse_timeout: 5000,
checks: %{
enabled: [
# 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
{Credo.Check.Design.AliasUsage, [priority: :low, if_nested_deeper_than: 2]},
{Credo.Check.Design.TagFIXME, []},
{Credo.Check.Design.TagTODO, [exit_status: 0]},
# 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, []},
{Credo.Check.Readability.PipeIntoAnonymousFunctions, []},
{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, []},
# Refactoring opportunities
{Credo.Check.Refactor.Apply, []},
{Credo.Check.Refactor.CondStatements, []},
{Credo.Check.Refactor.CyclomaticComplexity, [max_complexity: 12]},
{Credo.Check.Refactor.FunctionArity, [max_arity: 8]},
{Credo.Check.Refactor.LongQuoteBlocks, []},
{Credo.Check.Refactor.MatchInCondition, []},
{Credo.Check.Refactor.MapJoin, []},
{Credo.Check.Refactor.NegatedConditionsInUnless, []},
{Credo.Check.Refactor.NegatedConditionsWithElse, []},
{Credo.Check.Refactor.Nesting, [max_nesting: 3]},
{Credo.Check.Refactor.UnlessWithElse, []},
{Credo.Check.Refactor.WithClauses, []},
# Warnings
{Credo.Check.Warning.ApplicationConfigInModuleAttribute, []},
{Credo.Check.Warning.BoolOperationOnSameValues, []},
{Credo.Check.Warning.ExpensiveEmptyEnumCheck, []},
{Credo.Check.Warning.IExPry, []},
{Credo.Check.Warning.IoInspect, []},
{Credo.Check.Warning.OperationOnSameValues, []},
{Credo.Check.Warning.OperationWithConstantResult, []},
{Credo.Check.Warning.RaiseInsideRescue, []},
{Credo.Check.Warning.SpecWithStruct, []},
{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, []}
],
disabled: [
# Controversial and experimental checks
{Credo.Check.Consistency.MultiAliasImportRequireUse, []},
{Credo.Check.Consistency.UnusedVariableNames, []},
{Credo.Check.Design.DuplicatedCode, []},
{Credo.Check.Design.SkipTestWithoutComment, []},
{Credo.Check.Readability.AliasAs, []},
{Credo.Check.Readability.BlockPipe, []},
{Credo.Check.Readability.ImplTrue, []},
{Credo.Check.Readability.MultiAlias, []},
{Credo.Check.Readability.NestedFunctionCalls, []},
{Credo.Check.Readability.OneArityFunctionInPipe, []},
{Credo.Check.Readability.OnePipePerLine, []},
{Credo.Check.Readability.SeparateAliasRequire, []},
{Credo.Check.Readability.SingleFunctionToBlockPipe, []},
{Credo.Check.Readability.SinglePipe, []},
{Credo.Check.Readability.Specs, []},
{Credo.Check.Readability.StrictModuleLayout, []},
{Credo.Check.Readability.WithCustomTaggedTuple, []},
{Credo.Check.Refactor.ABCSize, []},
{Credo.Check.Refactor.AppendSingleItem, []},
{Credo.Check.Refactor.DoubleBooleanNegation, []},
{Credo.Check.Refactor.FilterReject, []},
{Credo.Check.Refactor.IoPuts, []},
{Credo.Check.Refactor.MapMap, []},
{Credo.Check.Refactor.ModuleDependencies, []},
{Credo.Check.Refactor.NegatedIsNil, []},
{Credo.Check.Refactor.PipeChainStart, []},
{Credo.Check.Refactor.RejectFilter, []},
{Credo.Check.Refactor.VariableRebinding, []},
{Credo.Check.Warning.LazyLogging, []},
{Credo.Check.Warning.LeakyEnvironment, []},
{Credo.Check.Warning.MapGetUnsafePass, []},
{Credo.Check.Warning.MixEnv, []},
{Credo.Check.Warning.UnsafeToAtom, []}
]
}
}
]
}
%{
configs: [
%{
name: "default",
# Default strict config
},
%{
name: "legacy",
files: %{
included: ["lib/legacy/"]
},
checks: %{
disabled: [
{Credo.Check.Readability.ModuleDoc, []}
]
}
}
]
}
# Use specific config
mix credo --config-name legacy
# Strict mode
mix credo --strict
# Show all issues
mix credo --all
# Only specific categories
mix credo --only readability,refactor
:higher - Critical issues:high - Important issues:normal - Default priority:low - Minor issues:ignore - Completely disablednpx claudepluginhub thebushidocollective/han --plugin credoExplains and fixes common Credo issues in Elixir code including module documentation, function complexity, pipe chains, and unused variables for consistency, design, readability, and refactoring.
Analyzes Elixir/Phoenix technical debt: duplicates, refactoring opportunities, Credo issues. Useful for code quality reviews, cleanup, or improvements.
Reviews Elixir .ex/.exs code for idiomatic style, pattern matching, OTP (GenServer/Supervisors), documentation (@doc/@spec), and security issues.