/
function_names.ex
148 lines (122 loc) · 4.29 KB
/
function_names.ex
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defmodule Credo.Check.Readability.FunctionNames do
use Credo.Check,
base_priority: :high,
param_defaults: [
allow_acronyms: false
],
explanations: [
check: """
Function, macro, and guard names are always written in snake_case in Elixir.
# snake_case
def handle_incoming_message(message) do
end
# not snake_case
def handleIncomingMessage(message) do
end
Like all `Readability` issues, this one is not a technical concern.
But you can improve the odds of others reading and liking your code by making
it easier to follow.
""",
params: [
allow_acronyms: "Allows acronyms like HTTP or OTP in function names."
]
]
alias Credo.Code.Name
@def_ops [:def, :defp, :defmacro, :defmacrop, :defguard, :defguardp]
@all_sigil_chars ~w(a A b B c C d D e E f F g G h H i I j J k K l L m M n N o O p P q Q r R s S t T u U v V w W x X y Y z Z)
@all_sigil_atoms Enum.map(@all_sigil_chars, &:"sigil_#{&1}")
# all non-special-form operators
@all_nonspecial_operators ~W(! && ++ -- .. <> =~ @ |> || != !== * + - / < <= == === > >= ||| &&& <<< >>> <<~ ~>> <~ ~> <~> <|> ^^^ ~~~)a
@doc false
@impl true
def run(%SourceFile{} = source_file, params \\ []) do
issue_meta = IssueMeta.for(source_file, params)
allow_acronyms? = Credo.Check.Params.get(params, :allow_acronyms, __MODULE__)
source_file
|> Credo.Code.prewalk(&traverse(&1, &2, issue_meta, allow_acronyms?), empty_issues())
|> issues_list()
end
defp empty_issues(), do: %{}
defp add_issue(issues, name, arity, issue), do: Map.put_new(issues, {name, arity}, issue)
defp issues_list(issues) do
issues
|> Map.values()
|> Enum.sort_by(& &1.line_no)
end
# Ignore sigil definitions
for sigil <- @all_sigil_atoms do
defp traverse(
{op, _meta, [{unquote(sigil), _sigil_meta, _args} | _tail]} = ast,
issues,
_issue_meta,
_allow_acronyms?
)
when op in [:def, :defmacro] do
{ast, issues}
end
defp traverse(
{op, _op_meta,
[{:when, _when_meta, [{unquote(sigil), _sigil_meta, _args} | _tail]}, _block]} = ast,
issues,
_issue_meta,
_allow_acronyms?
)
when op in [:def, :defmacro] do
{ast, issues}
end
end
# TODO: consider for experimental check front-loader (ast)
# NOTE: see above for how we want to avoid `sigil_X` definitions
for op <- @def_ops do
# Ignore variables named e.g. `defp`
defp traverse({unquote(op), _meta, nil} = ast, issues, _issue_meta, _allow_acronyms?) do
{ast, issues}
end
# ignore non-special-form (overridable) operators
defp traverse(
{unquote(op), _meta, [{operator, _at_meta, _args} | _tail]} = ast,
issues,
_issue_meta,
_allow_acronyms?
)
when operator in @all_nonspecial_operators do
{ast, issues}
end
defp traverse({unquote(op), _meta, arguments} = ast, issues, issue_meta, allow_acronyms?) do
{ast, issues_for_definition(arguments, issues, issue_meta, allow_acronyms?)}
end
end
defp traverse(ast, issues, _issue_meta, _allow_acronyms?) do
{ast, issues}
end
defp issues_for_definition(body, issues, issue_meta, allow_acronyms?) do
case Enum.at(body, 0) do
{:when, _when_meta, [{name, meta, args} | _guard]} ->
issues_for_name(name, args, meta, issues, issue_meta, allow_acronyms?)
{name, meta, args} when is_atom(name) ->
issues_for_name(name, args, meta, issues, issue_meta, allow_acronyms?)
_ ->
issues
end
end
defp issues_for_name({:unquote, _, _}, _args, _meta, issues, _issue_meta, _allow_acronyms?) do
issues
end
defp issues_for_name(name, args, meta, issues, issue_meta, allow_acronyms?) do
if name |> to_string |> Name.snake_case?(allow_acronyms?) do
issues
else
issue = issue_for(issue_meta, meta[:line], name)
arity = length(args || [])
add_issue(issues, name, arity, issue)
end
end
defp issue_for(issue_meta, line_no, trigger) do
format_issue(
issue_meta,
message: "Function/macro/guard names should be written in snake_case.",
trigger: trigger,
line_no: line_no
)
end
end