Implement autofix for C413 (#661)

Cargo.lock

@@ -2272,6 +2272,7 @@ dependencies = [
  "clap 4.0.15",
  "codegen",
  "itertools",
+ "libcst",
  "ruff",
  "rustpython-ast",
  "rustpython-common",

resources/test/fixtures/C413.py

@@ -1,4 +1,6 @@
 x = [2, 3, 1]
+list(x)
 list(sorted(x))
 reversed(sorted(x))
+reversed(sorted(x, key=lambda e: e))
 reversed(sorted(x, reverse=True))

ruff_dev/Cargo.toml

@@ -8,6 +8,7 @@ anyhow = { version = "1.0.60" }
 clap = { version = "4.0.1", features = ["derive"] }
 codegen = { version = "0.2.0" }
 itertools = { version = "0.10.5" }
+libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "32a044c127668df44582f85699358e67803b0d73" }
 ruff = { path = ".." }
 rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }
 rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }

ruff_dev/src/lib.rs

@@ -2,4 +2,5 @@ pub mod generate_check_code_prefix;
 pub mod generate_rules_table;
 pub mod generate_source_code;
 pub mod print_ast;
+pub mod print_cst;
 pub mod print_tokens;

ruff_dev/src/main.rs

@@ -1,7 +1,8 @@
 use anyhow::Result;
 use clap::{Parser, Subcommand};
 use ruff_dev::{
-    generate_check_code_prefix, generate_rules_table, generate_source_code, print_ast, print_tokens,
+    generate_check_code_prefix, generate_rules_table, generate_source_code, print_ast, print_cst,
+    print_tokens,
 };
 
 #[derive(Parser)]
@@ -22,6 +23,8 @@ enum Commands {
     GenerateSourceCode(generate_source_code::Cli),
     /// Print the AST for a given Python file.
     PrintAST(print_ast::Cli),
+    /// Print the LibCST CST for a given Python file.
+    PrintCST(print_cst::Cli),
     /// Print the token stream for a given Python file.
     PrintTokens(print_tokens::Cli),
 }
@@ -33,6 +36,7 @@ fn main() -> Result<()> {
         Commands::GenerateRulesTable(args) => generate_rules_table::main(args)?,
         Commands::GenerateSourceCode(args) => generate_source_code::main(args)?,
         Commands::PrintAST(args) => print_ast::main(args)?,
+        Commands::PrintCST(args) => print_cst::main(args)?,
         Commands::PrintTokens(args) => print_tokens::main(args)?,
     }
     Ok(())

ruff_dev/src/print_cst.rs

@@ -0,0 +1,25 @@
+//! Print the LibCST CST for a given Python file.
+
+use std::fs;
+use std::path::PathBuf;
+
+use anyhow::Result;
+use clap::Args;
+
+#[derive(Args)]
+pub struct Cli {
+    /// Python file for which to generate the CST.
+    #[arg(required = true)]
+    file: PathBuf,
+}
+
+pub fn main(cli: &Cli) -> Result<()> {
+    let contents = fs::read_to_string(&cli.file)?;
+    match libcst_native::parse_module(&contents, None) {
+        Ok(python_cst) => {
+            println!("{:#?}", python_cst);
+            Ok(())
+        }
+        Err(_) => Err(anyhow::anyhow!("Failed to parse CST")),
+    }
+}

src/check_ast.rs

@@ -1220,8 +1220,11 @@ where
                 if self.settings.enabled.contains(&CheckCode::C413) {
                     if let Some(check) =
                         flake8_comprehensions::checks::unnecessary_call_around_sorted(
+                            expr,
                             func,
                             args,
+                            self.locator,
+                            self.patch(),
                             Range::from_located(expr),
                         )
                     {

src/flake8_comprehensions/checks.rs

@@ -355,8 +355,11 @@ pub fn unnecessary_list_call(
 
 /// C413
 pub fn unnecessary_call_around_sorted(
+    expr: &Expr,
     func: &Expr,
     args: &[Expr],
+    locator: &SourceCodeLocator,
+    fix: bool,
     location: Range,
 ) -> Option<Check> {
     let outer = function_name(func)?;
@@ -365,10 +368,17 @@ pub fn unnecessary_call_around_sorted(
     }
     if let ExprKind::Call { func, .. } = &args.first()?.node {
         if function_name(func)? == "sorted" {
-            return Some(Check::new(
+            let mut check = Check::new(
                 CheckKind::UnnecessaryCallAroundSorted(outer.to_string()),
                 location,
-            ));
+            );
+            if fix {
+                match fixes::fix_unnecessary_call_around_sorted(locator, expr) {
+                    Ok(fix) => check.amend(fix),
+                    Err(e) => error!("Failed to generate fix: {}", e),
+                }
+            }
+            return Some(check);
         }
     }
     None

src/flake8_comprehensions/fixes.rs

@@ -1,8 +1,9 @@
 use anyhow::Result;
 use libcst_native::{
-    Arg, Call, Codegen, Dict, DictComp, DictElement, Element, Expr, Expression, LeftCurlyBrace,
+    Arg, AssignEqual, Call, Codegen, Dict, DictComp, DictElement, Element, Expr, Expression,
-    LeftParen, LeftSquareBracket, List, ListComp, Name, ParenthesizableWhitespace, RightCurlyBrace,
+    LeftCurlyBrace, LeftParen, LeftSquareBracket, List, ListComp, Name, ParenthesizableWhitespace,
-    RightParen, RightSquareBracket, Set, SetComp, SimpleString, SimpleWhitespace, Tuple,
+    RightCurlyBrace, RightParen, RightSquareBracket, Set, SetComp, SimpleString, SimpleWhitespace,
+    Tuple,
 };
 
 use crate::ast::types::Range;
@@ -649,6 +650,92 @@ pub fn fix_unnecessary_list_call(
     ))
 }
 
+/// (C413) Convert `list(sorted([2, 3, 1]))` to `sorted([2, 3, 1])`.
+/// (C413) Convert `reversed(sorted([2, 3, 1]))` to `sorted([2, 3, 1],
+/// reverse=True)`.
+pub fn fix_unnecessary_call_around_sorted(
+    locator: &SourceCodeLocator,
+    expr: &rustpython_ast::Expr,
+) -> Result<Fix> {
+    let module_text = locator.slice_source_code_range(&Range::from_located(expr));
+    let mut tree = match_module(&module_text)?;
+    let mut body = match_expr(&mut tree)?;
+    let outer_call = match_call(body)?;
+    let inner_call = match &outer_call.args[..] {
+        [arg] => {
+            if let Expression::Call(call) = &arg.value {
+                call
+            } else {
+                return Err(anyhow::anyhow!("Expected node to be: Expression::Call "));
+            }
+        }
+        _ => {
+            return Err(anyhow::anyhow!(
+                "Expected one argument in outer function call"
+            ))
+        }
+    };
+
+    if let Expression::Name(outer_name) = &*outer_call.func {
+        if outer_name.value == "list" {
+            body.value = Expression::Call(inner_call.clone());
+        } else {
+            let args = if inner_call.args.iter().any(|arg| {
+                matches!(
+                    arg.keyword,
+                    Some(Name {
+                        value: "reverse",
+                        ..
+                    })
+                )
+            }) {
+                inner_call.args.clone()
+            } else {
+                let mut args = inner_call.args.clone();
+                args.push(Arg {
+                    value: Expression::Name(Box::new(Name {
+                        value: "True",
+                        lpar: Default::default(),
+                        rpar: Default::default(),
+                    })),
+                    keyword: Some(Name {
+                        value: "reverse",
+                        lpar: Default::default(),
+                        rpar: Default::default(),
+                    }),
+                    equal: Some(AssignEqual {
+                        whitespace_before: Default::default(),
+                        whitespace_after: Default::default(),
+                    }),
+                    comma: Default::default(),
+                    star: Default::default(),
+                    whitespace_after_star: Default::default(),
+                    whitespace_after_arg: Default::default(),
+                });
+                args
+            };
+
+            body.value = Expression::Call(Box::new(Call {
+                func: inner_call.func.clone(),
+                args,
+                lpar: inner_call.lpar.clone(),
+                rpar: inner_call.rpar.clone(),
+                whitespace_after_func: inner_call.whitespace_after_func.clone(),
+                whitespace_before_args: inner_call.whitespace_before_args.clone(),
+            }))
+        }
+    }
+
+    let mut state = Default::default();
+    tree.codegen(&mut state);
+
+    Ok(Fix::replacement(
+        state.to_string(),
+        expr.location,
+        expr.end_location.unwrap(),
+    ))
+}
+
 /// (C416) Convert `[i for i in x]` to `list(x)`.
 pub fn fix_unnecessary_comprehension(
     locator: &SourceCodeLocator,

src/snapshots/ruff__linter__tests__C413_C413.py.snap

@@ -5,28 +5,73 @@ expression: checks
 - kind:
     UnnecessaryCallAroundSorted: list
   location:
-    row: 2
+    row: 3
     column: 0
   end_location:
-    row: 2
+    row: 3
     column: 15
-  fix: ~
+  fix:
+    patch:
+      content: sorted(x)
+      location:
+        row: 3
+        column: 0
+      end_location:
+        row: 3
+        column: 15
+    applied: false
 - kind:
     UnnecessaryCallAroundSorted: reversed
   location:
-    row: 3
+    row: 4
     column: 0
   end_location:
-    row: 3
+    row: 4
     column: 19
-  fix: ~
+  fix:
+    patch:
+      content: "sorted(x, reverse=True)"
+      location:
+        row: 4
+        column: 0
+      end_location:
+        row: 4
+        column: 19
+    applied: false
 - kind:
     UnnecessaryCallAroundSorted: reversed
   location:
-    row: 4
+    row: 5
     column: 0
   end_location:
-    row: 4
+    row: 5
+    column: 36
+  fix:
+    patch:
+      content: "sorted(x, key=lambda e: e, reverse=True)"
+      location:
+        row: 5
+        column: 0
+      end_location:
+        row: 5
+        column: 36
+    applied: false
+- kind:
+    UnnecessaryCallAroundSorted: reversed
+  location:
+    row: 6
+    column: 0
+  end_location:
+    row: 6
     column: 33
-  fix: ~
+  fix:
+    patch:
+      content: "sorted(x, reverse=True)"
+      location:
+        row: 6
+        column: 0
+      end_location:
+        row: 6
+        column: 33
+    applied: false