Enable abspath(__file__) removal (#336)

README.md

@@ -280,6 +280,7 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | T201 | PrintFound | `print` found |  | 🛠 |
 | T203 | PPrintFound | `pprint` found |  | 🛠 |
 | U001 | UselessMetaclassType | `__metaclass__ = type` is implied |  | 🛠 |
+| U002 | UnnecessaryAbspath | `abspath(__file__)` is unnecessary in Python 3.9 and later |  | 🛠 |
 | R001 | UselessObjectInheritance | Class `...` inherits from object |  | 🛠 |
 | R002 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |  | 🛠 |
 | M001 | UnusedNOQA | Unused `noqa` directive |  | 🛠 |

resources/test/fixtures/U002.py

@@ -0,0 +1,15 @@
+from os.path import abspath
+
+x = abspath(__file__)
+
+
+import os
+
+
+y = os.path.abspath(__file__)
+
+
+from os import path
+
+
+z = path.abspath(__file__)

src/ast/checks.rs

@@ -134,6 +134,27 @@ pub fn check_useless_metaclass_type(
     None
 }
 
+/// Check UnnecessaryAbspath compliance.
+pub fn check_unnecessary_abspath(func: &Expr, args: &Vec<Expr>, location: Range) -> Option<Check> {
+    // Validate the arguments.
+    if args.len() == 1 {
+        if let ExprKind::Name { id, .. } = &args[0].node {
+            if id == "__file__" {
+                match &func.node {
+                    ExprKind::Attribute { attr: id, .. } | ExprKind::Name { id, .. } => {
+                        if id == "abspath" {
+                            return Some(Check::new(CheckKind::UnnecessaryAbspath, location));
+                        }
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+
+    None
+}
+
 fn is_ambiguous_name(name: &str) -> bool {
     name == "l" || name == "I" || name == "O"
 }

src/check_ast.rs

@@ -772,6 +772,11 @@ where
                     };
                 }
 
+                // pyupgrade
+                if self.settings.enabled.contains(&CheckCode::U002) {
+                    plugins::unnecessary_abspath(self, expr, func, args);
+                }
+
                 if let ExprKind::Name { id, ctx } = &func.node {
                     if id == "locals" && matches!(ctx, ExprContext::Load) {
                         let scope = &mut self.scopes[*(self

src/checks.rs

@@ -53,7 +53,7 @@ pub const DEFAULT_CHECK_CODES: [CheckCode; 42] = [
     CheckCode::F901,
 ];
 
-pub const ALL_CHECK_CODES: [CheckCode; 53] = [
+pub const ALL_CHECK_CODES: [CheckCode; 54] = [
     // pycodestyle
     CheckCode::E402,
     CheckCode::E501,
@@ -111,6 +111,7 @@ pub const ALL_CHECK_CODES: [CheckCode; 53] = [
     CheckCode::T203,
     // pyupgrade
     CheckCode::U001,
+    CheckCode::U002,
     // Refactor
     CheckCode::R001,
     CheckCode::R002,
@@ -177,6 +178,7 @@ pub enum CheckCode {
     T203,
     // pyupgrade
     U001,
+    U002,
     // Refactor
     R001,
     R002,
@@ -246,6 +248,7 @@ impl FromStr for CheckCode {
             "T203" => Ok(CheckCode::T203),
             // pyupgrade
             "U001" => Ok(CheckCode::U001),
+            "U002" => Ok(CheckCode::U002),
             // Refactor
             "R001" => Ok(CheckCode::R001),
             "R002" => Ok(CheckCode::R002),
@@ -316,6 +319,7 @@ impl CheckCode {
             CheckCode::T203 => "T203",
             // pyupgrade
             CheckCode::U001 => "U001",
+            CheckCode::U002 => "U002",
             // Refactor
             CheckCode::R001 => "R001",
             CheckCode::R002 => "R002",
@@ -395,6 +399,7 @@ impl CheckCode {
             CheckCode::T203 => CheckKind::PPrintFound,
             // pyupgrade
             CheckCode::U001 => CheckKind::UselessMetaclassType,
+            CheckCode::U002 => CheckKind::UnnecessaryAbspath,
             // Refactor
             CheckCode::R001 => CheckKind::UselessObjectInheritance("...".to_string()),
             CheckCode::R002 => CheckKind::NoAssertEquals,
@@ -446,7 +451,6 @@ pub enum CheckKind {
     ModuleImportNotAtTopOfFile,
     MultiValueRepeatedKeyLiteral,
     MultiValueRepeatedKeyVariable(String),
-    NoAssertEquals,
     NoneComparison(RejectedCmpop),
     NotInTest,
     NotIsTest,
@@ -460,10 +464,7 @@ pub enum CheckKind {
     UndefinedLocal(String),
     UndefinedName(String),
     UnusedImport(String),
-    UnusedNOQA(Option<String>),
     UnusedVariable(String),
-    UselessMetaclassType,
-    UselessObjectInheritance(String),
     YieldOutsideFunction,
     // flake8-builtin
     BuiltinVariableShadowing(String),
@@ -476,6 +477,14 @@ pub enum CheckKind {
     // flake8-print
     PrintFound,
     PPrintFound,
+    // pyupgrade
+    UnnecessaryAbspath,
+    UselessMetaclassType,
+    // Refactor
+    NoAssertEquals,
+    UselessObjectInheritance(String),
+    // Meta
+    UnusedNOQA(Option<String>),
 }
 
 impl CheckKind {
@@ -536,6 +545,7 @@ impl CheckKind {
             CheckKind::PrintFound => "PrintFound",
             CheckKind::PPrintFound => "PPrintFound",
             // pyupgrade
+            CheckKind::UnnecessaryAbspath => "UnnecessaryAbspath",
             CheckKind::UselessMetaclassType => "UselessMetaclassType",
             // Refactor
             CheckKind::NoAssertEquals => "NoAssertEquals",
@@ -602,6 +612,7 @@ impl CheckKind {
             CheckKind::PrintFound => &CheckCode::T201,
             CheckKind::PPrintFound => &CheckCode::T203,
             // pyupgrade
+            CheckKind::UnnecessaryAbspath => &CheckCode::U002,
             CheckKind::UselessMetaclassType => &CheckCode::U001,
             // Refactor
             CheckKind::NoAssertEquals => &CheckCode::R002,
@@ -761,6 +772,9 @@ impl CheckKind {
             CheckKind::PrintFound => "`print` found".to_string(),
             CheckKind::PPrintFound => "`pprint` found".to_string(),
             // pyupgrade
+            CheckKind::UnnecessaryAbspath => {
+                "`abspath(__file__)` is unnecessary in Python 3.9 and later".to_string()
+            }
             CheckKind::UselessMetaclassType => "`__metaclass__ = type` is implied".to_string(),
             // Refactor
             CheckKind::NoAssertEquals => {
@@ -785,6 +799,7 @@ impl CheckKind {
                 | CheckKind::PPrintFound
                 | CheckKind::PrintFound
                 | CheckKind::SuperCallWithParameters
+                | CheckKind::UnnecessaryAbspath
                 | CheckKind::UnusedImport(_)
                 | CheckKind::UnusedNOQA(_)
                 | CheckKind::UselessMetaclassType

src/linter.rs

@@ -845,4 +845,16 @@ mod tests {
         insta::assert_yaml_snapshot!(checks);
         Ok(())
     }
+
+    #[test]
+    fn u002() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U002.py"),
+            &settings::Settings::for_rule(CheckCode::U002),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
 }

src/plugins.rs

@@ -4,6 +4,7 @@ mod if_tuple;
 mod invalid_print_syntax;
 mod print_call;
 mod super_call_with_parameters;
+mod unnecessary_abspath;
 mod useless_metaclass_type;
 mod useless_object_inheritance;
 
@@ -13,5 +14,6 @@ pub use if_tuple::if_tuple;
 pub use invalid_print_syntax::invalid_print_syntax;
 pub use print_call::print_call;
 pub use super_call_with_parameters::super_call_with_parameters;
+pub use unnecessary_abspath::unnecessary_abspath;
 pub use useless_metaclass_type::useless_metaclass_type;
 pub use useless_object_inheritance::useless_object_inheritance;

src/plugins/unnecessary_abspath.rs

@@ -0,0 +1,25 @@
+use rustpython_ast::Expr;
+
+use crate::ast::checks;
+use crate::ast::types::{CheckLocator, Range};
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::Fix;
+
+pub fn unnecessary_abspath(checker: &mut Checker, expr: &Expr, func: &Expr, args: &Vec<Expr>) {
+    if let Some(mut check) = checks::check_unnecessary_abspath(
+        func,
+        args,
+        checker.locate_check(Range::from_located(expr)),
+    ) {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            check.amend(Fix {
+                content: "__file__".to_string(),
+                location: expr.location,
+                end_location: expr.end_location,
+                applied: false,
+            });
+        }
+        checker.add_check(check);
+    }
+}