Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

LexCredo.Check.Warning.NoPipeIntoCase — superseded by the built-in Credo.Check.Readability.BlockPipe, which covers |> into any block expression, not just case. Enable BlockPipe in .credo.exs instead.
LexCredo.Check.Warning.NoTaggedWithClauses — superseded by the built-in Credo.Check.Readability.WithCustomTaggedTuple, which is broader (catches any same-tag pattern, not only :ok/:error wrappers). Enable WithCustomTaggedTuple in .credo.exs instead.

LexCredo.Check.Warning.NonBooleanWithStrictOperator — flags and/or/not when any operand is clearly non-boolean (struct field access without ? suffix, non-boolean literal, nil, etc.); suggests &&/||/! to avoid a runtime ArgumentError or misleading truthy/falsy semantics. Complements PreferBooleanOperators.
LexCredo.Check.Warning.StructMatchInFunctionHead — flags %Struct{} = param at the top level of a function body when param is a plain-variable argument. Moving the struct match to the function head makes the type visible in the signature and enables Elixir's type checker to infer the parameter type. Only top-level body statements are checked; matches nested inside case, if, with, etc. are left alone.
LexCredo.Check.Warning.PreferIsNil — flags == nil, != nil, === nil, and !== nil comparisons (both operand orders); suggests is_nil(x) and not is_nil(x) for consistency with the is_* guard family. Note: conflicts with the built-in Credo.Check.Refactor.NegatedIsNil; disable one.

Initial release.

Checks – Design

LexCredo.Check.Design.NoNestedModules — flags module definitions nested inside another module; skips test files by default (exclude_test_files: true).

Checks – Readability

LexCredo.Check.Readability.DocExamplesSection — flags public functions whose @doc string contains code blocks but no ## Examples heading.

Checks – Refactor

LexCredo.Check.Refactor.NoEnumWrapperFunctions — flags single-function bodies that do nothing but delegate to Enum/Stream (map, flat_map, each, map_reduce, flat_map_reduce, scan).

Checks – Warning

LexCredo.Check.Warning.NoComplexWithElse — flags with expressions whose else block exceeds max_else_clauses (default: 1).
LexCredo.Check.Warning.NoEnumAllAssert — flags assert Enum.all?/2 in test files; suggests per-element assertions for clearer failure messages.
LexCredo.Check.Warning.NoPipeIntoCase — flags |> case do patterns; suggests binding the intermediate value to a named variable first.
LexCredo.Check.Warning.NoProcessSleepInTests — flags Process.sleep/1 and Process.alive?/1 in test files; suggests Process.monitor/1 + assert_receive for deterministic synchronisation.
LexCredo.Check.Warning.NoTaggedWithClauses — flags the {:tag, {:ok, _}} <- {:tag, expr} workaround used to identify which with clause failed in the else block.
LexCredo.Check.Warning.PreferBooleanOperators — flags &&, ||, and ! when at least one operand is a boolean-typed expression; suggests and, or, and not. Does not flag truthy/falsy short-circuit patterns such as user && user.name.
LexCredo.Check.Warning.UsePositiveTypeGuards — flags negated type guards in function heads (not is_nil(x), x != nil, etc.); suggests a specific positive guard that accurately constrains the clause.
LexCredo.Check.Warning.UseStartSupervised — flags direct start_link/ start calls to GenServer, Agent, Task, Supervisor, and DynamicSupervisor in test files; suggests start_supervised!/1.

General

exclude_test_files boolean parameter on all checks — set to true to skip files under test/; defaults to true for NoNestedModules, false for all others.
GitHub Actions CI workflow: format check → compile (warnings-as-errors) → credo --strict → ExCoveralls; reads Elixir/OTP versions from .tool-versions.
ExCoveralls configured with an 80 % minimum line-coverage threshold.
ExDoc configured with main: "readme", check modules grouped by category, and README / CHANGELOG / LICENSE included as extras.
MIT license.

PreferBooleanOperators: boolean_like?/1 is now recursive for &&/|| — they are only considered boolean-like when their own operands are boolean-like. This eliminates false positives on truthy/falsy short-circuit idioms such as (user && user.name) || "default".
UsePositiveTypeGuards: extended pattern matching to cover not is_*(x) for all standard type-guard functions, not just is_nil.