Document flake8-unused-arguments (#4147)

crates/ruff/src/rules/flake8_unused_arguments/rules.rs

@@ -16,6 +16,24 @@ use crate::checkers::ast::Checker;
 use super::helpers;
 use super::types::Argumentable;
 
+/// ## What it does
+/// Checks for the presence of unused arguments in function definitions.
+///
+/// ## Why is this bad?
+/// An argument that is defined but not used is likely a mistake, and should
+/// be removed to avoid confusion.
+///
+/// ## Example
+/// ```python
+/// def foo(bar, baz):
+///     return bar * 2
+/// ```
+///
+/// Use instead:
+/// ```python
+/// def foo(bar):
+///     return bar * 2
+/// ```
 #[violation]
 pub struct UnusedFunctionArgument {
     pub name: String,
@@ -29,6 +47,25 @@ impl Violation for UnusedFunctionArgument {
     }
 }
 
+/// ## What it does
+/// Checks for the presence of unused arguments in instance method definitions.
+///
+/// ## Why is this bad?
+/// An argument that is defined but not used is likely a mistake, and should
+/// be removed to avoid confusion.
+///
+/// ## Example
+/// ```python
+/// class MyClass:
+///     def my_method(self, arg1, arg2):
+///         print(arg1)
+/// ```
+///
+/// Use instead:
+/// ```python
+/// class MyClass:
+///     def my_method(self, arg1):
+/// ```
 #[violation]
 pub struct UnusedMethodArgument {
     pub name: String,
@@ -42,6 +79,34 @@ impl Violation for UnusedMethodArgument {
     }
 }
 
+/// ## What it does
+/// Checks for the presence of unused arguments in class method definitions.
+///
+/// ## Why is this bad?
+/// An argument that is defined but not used is likely a mistake, and should
+/// be removed to avoid confusion.
+///
+/// ## Example
+/// ```python
+/// class MyClass:
+///     @classmethod
+///     def my_method(self, arg1, arg2):
+///         print(arg1)
+///
+///     def other_method(self):
+///         self.my_method("foo", "bar")
+/// ```
+///
+/// Use instead:
+/// ```python
+/// class MyClass:
+///     @classmethod
+///     def my_method(self, arg1):
+///         print(arg1)
+///
+///     def other_method(self):
+///         self.my_method("foo", "bar")
+/// ```
 #[violation]
 pub struct UnusedClassMethodArgument {
     pub name: String,
@@ -55,6 +120,34 @@ impl Violation for UnusedClassMethodArgument {
     }
 }
 
+/// ## What it does
+/// Checks for the presence of unused arguments in static method definitions.
+///
+/// ## Why is this bad?
+/// An argument that is defined but not used is likely a mistake, and should
+/// be removed to avoid confusion.
+///
+/// ## Example
+/// ```python
+/// class MyClass:
+///     @staticmethod
+///     def my_static_method(self, arg1, arg2):
+///         print(arg1)
+///
+///     def other_method(self):
+///         self.my_static_method("foo", "bar")
+/// ```
+///
+/// Use instead:
+/// ```python
+/// class MyClass:
+///     @static
+///     def my_static_method(self, arg1):
+///         print(arg1)
+///
+///     def other_method(self):
+///         self.my_static_method("foo", "bar")
+/// ```
 #[violation]
 pub struct UnusedStaticMethodArgument {
     pub name: String,
@@ -68,6 +161,25 @@ impl Violation for UnusedStaticMethodArgument {
     }
 }
 
+/// ## What it does
+/// Checks for the presence of unused arguments in lambda expression
+/// definitions.
+///
+/// ## Why is this bad?
+/// An argument that is defined but not used is likely a mistake, and should
+/// be removed to avoid confusion.
+///
+/// ## Example
+/// ```python
+/// my_list = [1, 2, 3, 4, 5]
+/// squares = map(lambda x, y: x**2, my_list)
+/// ```
+///
+/// Use instead:
+/// ```python
+/// my_list = [1, 2, 3, 4, 5]
+/// squares = map(lambda x: x**2, my_list)
+/// ```
 #[violation]
 pub struct UnusedLambdaArgument {
     pub name: String,