Implement autofix for B009 (#684)

README.md

@@ -501,7 +501,7 @@ For more, see [flake8-bugbear](https://pypi.org/project/flake8-bugbear/22.10.27/
 | B006 | MutableArgumentDefault | Do not use mutable data structures for argument defaults. |  |
 | B007 | UnusedLoopControlVariable | Loop control variable `i` not used within the loop body. | 🛠 |
 | B008 | FunctionCallArgumentDefault | Do not perform function calls in argument defaults. |  |
-| B009 | GetAttrWithConstant | Do not call `getattr` with a constant attribute value, it is not any safer than normal property access. |  |
+| B009 | GetAttrWithConstant | Do not call `getattr` with a constant attribute value, it is not any safer than normal property access. | 🛠 |
 | B010 | SetAttrWithConstant | Do not call setattr with a constant attribute value, it is not any safer than normal property access. |  |
 | B011 | DoNotAssertFalse | Do not `assert False` (`python -O` removes these calls), raise `AssertionError()` | 🛠 |
 | B013 | RedundantTupleInExceptionHandler | A length-one tuple literal is redundant. Write `except ValueError:` instead of `except (ValueError,):`. |  |

resources/test/fixtures/B009_B010.py

@@ -1,7 +1,7 @@
 """
 Should emit:
-B009 - Line 17, 18, 19, 44
+B009 - Line 18, 19, 20, 21, 22
-B010 - Line 28, 29, 30
+B010 - Line 33, 34, 35, 36
 """
 
 # Valid getattr usage
@@ -11,37 +11,26 @@ getattr(foo, "bar{foo}".format(foo="a"), None)
 getattr(foo, "bar{foo}".format(foo="a"))
 getattr(foo, bar, None)
 getattr(foo, "123abc")
+getattr(foo, r"123\abc")
 getattr(foo, "except")
 
 # Invalid usage
 getattr(foo, "bar")
 getattr(foo, "_123abc")
 getattr(foo, "abc123")
+getattr(foo, r"abc123")
+_ = lambda x: getattr(x, "bar")
 
 # Valid setattr usage
 setattr(foo, bar, None)
 setattr(foo, "bar{foo}".format(foo="a"), None)
 setattr(foo, "123abc", None)
+setattr(foo, r"123\abc", None)
 setattr(foo, "except", None)
+_ = lambda x: setattr(x, "bar", 1)
 
 # Invalid usage
 setattr(foo, "bar", None)
 setattr(foo, "_123abc", None)
 setattr(foo, "abc123", None)
-
+setattr(foo, r"abc123", None)
-# Allow use of setattr within lambda expression
-# since assignment is not valid in this context.
-c = lambda x: setattr(x, "some_attr", 1)
-
-
-class FakeCookieStore:
-    def __init__(self, has_setter):
-        self.cookie_filter = None
-        if has_setter:
-            self.setCookieFilter = lambda func: setattr(self, "cookie_filter", func)
-
-
-# getattr is still flagged within lambda though
-c = lambda x: getattr(x, "some_attr")
-# should be replaced with
-c = lambda x: x.some_attr

src/check_ast.rs

@@ -1075,11 +1075,11 @@ where
                     flake8_bugbear::plugins::getattr_with_constant(self, expr, func, args);
                 }
                 if self.settings.enabled.contains(&CheckCode::B010) {
-                    if !self
+                    if self
                         .scopes
                         .iter()
                         .rev()
-                        .any(|scope| matches!(scope.kind, ScopeKind::Lambda))
+                        .all(|scope| !matches!(scope.kind, ScopeKind::Lambda))
                     {
                         flake8_bugbear::plugins::setattr_with_constant(self, expr, func, args);
                     }
@@ -1473,7 +1473,6 @@ where
                 }
                 self.push_scope(Scope::new(ScopeKind::Lambda))
             }
-
             ExprKind::ListComp { elt, generators } | ExprKind::SetComp { elt, generators } => {
                 if self.settings.enabled.contains(&CheckCode::C416) {
                     if let Some(check) = flake8_comprehensions::checks::unnecessary_comprehension(
@@ -1489,7 +1488,6 @@ where
                 }
                 self.push_scope(Scope::new(ScopeKind::Generator))
             }
-
             ExprKind::GeneratorExp { .. } | ExprKind::DictComp { .. } => {
                 self.push_scope(Scope::new(ScopeKind::Generator))
             }

src/checks.rs

@@ -1743,6 +1743,7 @@ impl CheckKind {
                 | CheckKind::DeprecatedUnittestAlias(_, _)
                 | CheckKind::DoNotAssertFalse
                 | CheckKind::DuplicateHandlerException(_)
+                | CheckKind::GetAttrWithConstant
                 | CheckKind::IsLiteral
                 | CheckKind::NewLineAfterLastParagraph
                 | CheckKind::NewLineAfterSectionName(_)

src/flake8_bugbear/plugins/getattr_with_constant.rs

@@ -1,29 +1,53 @@
-use rustpython_ast::{Constant, Expr, ExprKind};
+use rustpython_ast::{Constant, Expr, ExprContext, ExprKind};
 
 use crate::ast::types::Range;
+use crate::autofix::Fix;
 use crate::check_ast::Checker;
 use crate::checks::{Check, CheckKind};
+use crate::code_gen::SourceGenerator;
 use crate::flake8_bugbear::constants::IDENTIFIER_REGEX;
 use crate::python::keyword::KWLIST;
 
-/// B009
+fn attribute(value: &Expr, attr: &str) -> Expr {
+    Expr::new(
+        Default::default(),
+        Default::default(),
+        ExprKind::Attribute {
+            value: Box::new(value.clone()),
+            attr: attr.to_string(),
+            ctx: ExprContext::Load,
+        },
+    )
+}
+
 pub fn getattr_with_constant(checker: &mut Checker, expr: &Expr, func: &Expr, args: &[Expr]) {
     if let ExprKind::Name { id, .. } = &func.node {
         if id == "getattr" {
-            if let [_, arg] = args {
+            if let [obj, arg] = args {
                 if let ExprKind::Constant {
                     value: Constant::Str(value),
                     ..
                 } = &arg.node
                 {
                     if IDENTIFIER_REGEX.is_match(value) && !KWLIST.contains(&value.as_str()) {
-                        checker.add_check(Check::new(
+                        let mut check =
-                            CheckKind::GetAttrWithConstant,
+                            Check::new(CheckKind::GetAttrWithConstant, Range::from_located(expr));
-                            Range::from_located(expr),
+                        if checker.patch() {
+                            let mut generator = SourceGenerator::new();
+                            if let Ok(()) = generator.unparse_expr(&attribute(obj, value), 0) {
+                                if let Ok(content) = generator.generate() {
+                                    check.amend(Fix::replacement(
+                                        content,
+                                        expr.location,
+                                        expr.end_location.unwrap(),
                                     ));
                                 }
                             }
                         }
+                        checker.add_check(check);
+                    }
+                }
+            }
         }
     }
 }

src/flake8_bugbear/plugins/setattr_with_constant.rs

@@ -18,7 +18,7 @@ pub fn setattr_with_constant(checker: &mut Checker, expr: &Expr, func: &Expr, ar
                 {
                     if IDENTIFIER_REGEX.is_match(value) && !KWLIST.contains(&value.as_str()) {
                         checker.add_check(Check::new(
-                            CheckKind::GetAttrWithConstant,
+                            CheckKind::SetAttrWithConstant,
                             Range::from_located(expr),
                         ));
                     }

src/snapshots/ruff__linter__tests__B009_B009_B010.py.snap

@@ -4,34 +4,87 @@ expression: checks
 ---
 - kind: GetAttrWithConstant
   location:
-    row: 17
+    row: 18
     column: 0
   end_location:
-    row: 17
+    row: 18
     column: 19
-  fix: ~
+  fix:
-- kind: GetAttrWithConstant
+    patch:
+      content: foo.bar
       location:
         row: 18
         column: 0
       end_location:
         row: 18
+        column: 19
+    applied: false
+- kind: GetAttrWithConstant
+  location:
+    row: 19
+    column: 0
+  end_location:
+    row: 19
     column: 23
-  fix: ~
+  fix:
-- kind: GetAttrWithConstant
+    patch:
+      content: foo._123abc
       location:
         row: 19
         column: 0
       end_location:
         row: 19
-    column: 22
+        column: 23
-  fix: ~
+    applied: false
 - kind: GetAttrWithConstant
   location:
-    row: 45
+    row: 20
+    column: 0
+  end_location:
+    row: 20
+    column: 22
+  fix:
+    patch:
+      content: foo.abc123
+      location:
+        row: 20
+        column: 0
+      end_location:
+        row: 20
+        column: 22
+    applied: false
+- kind: GetAttrWithConstant
+  location:
+    row: 21
+    column: 0
+  end_location:
+    row: 21
+    column: 23
+  fix:
+    patch:
+      content: foo.abc123
+      location:
+        row: 21
+        column: 0
+      end_location:
+        row: 21
+        column: 23
+    applied: false
+- kind: GetAttrWithConstant
+  location:
+    row: 22
     column: 14
   end_location:
-    row: 45
+    row: 22
-    column: 37
+    column: 31
-  fix: ~
+  fix:
+    patch:
+      content: x.bar
+      location:
+        row: 22
+        column: 14
+      end_location:
+        row: 22
+        column: 31
+    applied: false
 

src/snapshots/ruff__linter__tests__B010_B009_B010.py.snap

@@ -2,28 +2,5 @@
 source: src/linter.rs
 expression: checks
 ---
-- kind: GetAttrWithConstant
+[]
-  location:
-    row: 28
-    column: 0
-  end_location:
-    row: 28
-    column: 25
-  fix: ~
-- kind: GetAttrWithConstant
-  location:
-    row: 29
-    column: 0
-  end_location:
-    row: 29
-    column: 29
-  fix: ~
-- kind: GetAttrWithConstant
-  location:
-    row: 30
-    column: 0
-  end_location:
-    row: 30
-    column: 28
-  fix: ~