diff --git a/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B006_10.py b/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B006_10.py new file mode 100644 index 0000000000..88d6247362 --- /dev/null +++ b/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B006_10.py @@ -0,0 +1,21 @@ +# Module-level mutable "constant" +MY_SET = {"ABC", "DEF"} # plain set +MY_LIST = [1, 2, 3] # plain list +MY_DICT = {"key": "value"} # plain dict + +# NOT triggering B006 (correct - PEP 8 specifies that UPPER_CASE variables are considered constants) +def func_A(s: set[str] = MY_SET): + return s + +# Triggering B006 (correct) +def func_B(s: set[str] = {"ABC", "DEF"}): + return s + +# NOT triggering B006 (correct - PEP 8 specifies that UPPER_CASE variables are considered constants) +def func_C(items: list[int] = MY_LIST): + return items + +# NOT triggering B006 (correct - PEP 8 specifies that UPPER_CASE variables are considered constants) +def func_D(data: dict[str, str] = MY_DICT): + return data + diff --git a/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B006_11.py b/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B006_11.py new file mode 100644 index 0000000000..dd279030c2 --- /dev/null +++ b/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B006_11.py @@ -0,0 +1,39 @@ +# Test nested function reading value from outer scope +def outer_function(): + my_list = [1, 2, 3] # Assignment in outer function + + # Should trigger B006 - nested function using mutable from outer scope + def inner_function(items=my_list): + return items + + return inner_function + + +# Test that imports don't trigger B006 (assignment restriction) +from some_module import IMPORTED_LIST + +# Should NOT trigger B006 - imported names are not assignments +def func_with_import(items=IMPORTED_LIST): + return items + + +# Test that function parameters don't trigger B006 (assignment restriction) +def func_with_param(param_list): + # Should NOT trigger B006 - function parameters are not assignments + def nested_func(items=param_list): + return items + + return nested_func + + +# Test module-level assignment that should trigger B006 +module_list = [1, 2, 3] # Module-level assignment + +# Should trigger B006 - module-level assignment used as default +def func_with_module_var(items=module_list): + return items + + +# Test that non-assignment bindings don't trigger B006 +# (This would require a more complex setup to actually test, so we'll focus on the key cases above) + diff --git a/crates/ruff_linter/src/rules/flake8_bugbear/mod.rs b/crates/ruff_linter/src/rules/flake8_bugbear/mod.rs index 163d175872..44af8c2232 100644 --- a/crates/ruff_linter/src/rules/flake8_bugbear/mod.rs +++ b/crates/ruff_linter/src/rules/flake8_bugbear/mod.rs @@ -48,6 +48,8 @@ mod tests { #[test_case(Rule::MutableArgumentDefault, Path::new("B006_7.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_8.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_9.py"))] + #[test_case(Rule::MutableArgumentDefault, Path::new("B006_10.py"))] + #[test_case(Rule::MutableArgumentDefault, Path::new("B006_11.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_B008.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_1.pyi"))] #[test_case(Rule::NoExplicitStacklevel, Path::new("B028.py"))] @@ -93,6 +95,8 @@ mod tests { #[test_case(Rule::MutableArgumentDefault, Path::new("B006_7.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_8.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_9.py"))] + #[test_case(Rule::MutableArgumentDefault, Path::new("B006_10.py"))] + #[test_case(Rule::MutableArgumentDefault, Path::new("B006_11.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_B008.py"))] #[test_case(Rule::MutableArgumentDefault, Path::new("B006_1.pyi"))] fn preview_rules(rule_code: Rule, path: &Path) -> Result<()> { diff --git a/crates/ruff_linter/src/rules/flake8_bugbear/rules/mutable_argument_default.rs b/crates/ruff_linter/src/rules/flake8_bugbear/rules/mutable_argument_default.rs index c0b1b5e840..a2d22de84c 100644 --- a/crates/ruff_linter/src/rules/flake8_bugbear/rules/mutable_argument_default.rs +++ b/crates/ruff_linter/src/rules/flake8_bugbear/rules/mutable_argument_default.rs @@ -7,7 +7,10 @@ use ruff_python_ast::token::parenthesized_range; use ruff_python_ast::{self as ast, Expr, ParameterWithDefault}; use ruff_python_semantic::SemanticModel; use ruff_python_semantic::analyze::function_type::is_stub; -use ruff_python_semantic::analyze::typing::{is_immutable_annotation, is_mutable_expr}; +use ruff_python_semantic::analyze::typing::{ + find_binding_value, is_immutable_annotation, is_mutable_expr, +}; +use ruff_python_stdlib::str; use ruff_python_trivia::{indentation_at_offset, textwrap}; use ruff_source_file::LineRanges; use ruff_text_size::Ranged; @@ -142,6 +145,30 @@ fn is_guaranteed_mutable_expr(expr: &Expr, semantic: &SemanticModel) -> bool { elts.iter().any(|e| is_guaranteed_mutable_expr(e, semantic)) } Expr::Named(ast::ExprNamed { value, .. }) => is_guaranteed_mutable_expr(value, semantic), + Expr::Name(name) => { + // Exclude UPPER_CASE constants (PEP 8 convention - meant to be read-only) + if str::is_cased_uppercase(&name.id) { + return false; + } + // Resolve the name in the current scope (module-level, function-level, etc.) + // This can resolve constants, non-constants, and any name in the current scope + let Some(binding_id) = semantic.only_binding(name) else { + return false; + }; + let binding = semantic.binding(binding_id); + // Only check assignments (not imports, function parameters, etc.) + // This restriction ensures we only flag cases where a mutable object is explicitly + // assigned to a name, which is then used as a default argument. + if !binding.kind.is_assignment() { + return false; + } + // Get the assigned value and check if it's mutable + if let Some(value) = find_binding_value(binding, semantic) { + is_guaranteed_mutable_expr(value, semantic) + } else { + false + } + } _ => is_mutable_expr(expr, semantic), } } diff --git a/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B006_B006_10.py.snap b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B006_B006_10.py.snap new file mode 100644 index 0000000000..1c9554b69b --- /dev/null +++ b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B006_B006_10.py.snap @@ -0,0 +1,23 @@ +--- +source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs +--- +B006 [*] Do not use mutable data structures for argument defaults + --> B006_10.py:11:26 + | +10 | # Triggering B006 (correct) +11 | def func_B(s: set[str] = {"ABC", "DEF"}): + | ^^^^^^^^^^^^^^ +12 | return s + | +help: Replace with `None`; initialize within function +8 | return s +9 | +10 | # Triggering B006 (correct) + - def func_B(s: set[str] = {"ABC", "DEF"}): +11 + def func_B(s: set[str] = None): +12 + if s is None: +13 + s = {"ABC", "DEF"} +14 | return s +15 | +16 | # NOT triggering B006 (correct - PEP 8 specifies that UPPER_CASE variables are considered constants) +note: This is an unsafe fix and may change runtime behavior diff --git a/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B006_B006_11.py.snap b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B006_B006_11.py.snap new file mode 100644 index 0000000000..967e60a4f9 --- /dev/null +++ b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B006_B006_11.py.snap @@ -0,0 +1,4 @@ +--- +source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs +--- + diff --git a/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B006_B006_10.py.snap b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B006_B006_10.py.snap new file mode 100644 index 0000000000..1c9554b69b --- /dev/null +++ b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B006_B006_10.py.snap @@ -0,0 +1,23 @@ +--- +source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs +--- +B006 [*] Do not use mutable data structures for argument defaults + --> B006_10.py:11:26 + | +10 | # Triggering B006 (correct) +11 | def func_B(s: set[str] = {"ABC", "DEF"}): + | ^^^^^^^^^^^^^^ +12 | return s + | +help: Replace with `None`; initialize within function +8 | return s +9 | +10 | # Triggering B006 (correct) + - def func_B(s: set[str] = {"ABC", "DEF"}): +11 + def func_B(s: set[str] = None): +12 + if s is None: +13 + s = {"ABC", "DEF"} +14 | return s +15 | +16 | # NOT triggering B006 (correct - PEP 8 specifies that UPPER_CASE variables are considered constants) +note: This is an unsafe fix and may change runtime behavior diff --git a/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B006_B006_11.py.snap b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B006_B006_11.py.snap new file mode 100644 index 0000000000..2a57e5ad16 --- /dev/null +++ b/crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B006_B006_11.py.snap @@ -0,0 +1,44 @@ +--- +source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs +--- +B006 [*] Do not use mutable data structures for argument defaults + --> B006_11.py:6:30 + | +5 | # Should trigger B006 - nested function using mutable from outer scope +6 | def inner_function(items=my_list): + | ^^^^^^^ +7 | return items + | +help: Replace with `None`; initialize within function +3 | my_list = [1, 2, 3] # Assignment in outer function +4 | +5 | # Should trigger B006 - nested function using mutable from outer scope + - def inner_function(items=my_list): +6 + def inner_function(items=None): +7 + if items is None: +8 + items = my_list +9 | return items +10 | +11 | return inner_function +note: This is an unsafe fix and may change runtime behavior + +B006 [*] Do not use mutable data structures for argument defaults + --> B006_11.py:33:32 + | +32 | # Should trigger B006 - module-level assignment used as default +33 | def func_with_module_var(items=module_list): + | ^^^^^^^^^^^ +34 | return items + | +help: Replace with `None`; initialize within function +30 | module_list = [1, 2, 3] # Module-level assignment +31 | +32 | # Should trigger B006 - module-level assignment used as default + - def func_with_module_var(items=module_list): +33 + def func_with_module_var(items=None): +34 + if items is None: +35 + items = module_list +36 | return items +37 | +38 | +note: This is an unsafe fix and may change runtime behavior