Credence.Pattern.NoTrailingNewlineInDoc (credence v0.5.0)

Detects @doc, @moduledoc, and @typedoc strings that contain a trailing \n escape sequence.

LLMs frequently generate documentation strings with a trailing \n because Python docstrings use trailing newlines. In Elixir, the closing " or """ handles line termination — the \n produces an unnecessary blank line in the rendered documentation.

Bad

@doc "Finds the missing number in a list.\n"

@moduledoc "A module for palindrome checking.\n"

Good

@doc "Finds the missing number in a list."

@moduledoc "A module for palindrome checking."

Auto-fix

Strips trailing \n from single-line doc strings (strings where the only newlines are trailing). Heredoc-style docs (""") are not flagged or modified — their trailing \n is structural and expected.