add autofix for PLC0208 (#7887)

crates/ruff_linter/resources/test/fixtures/pylint/iteration_over_set.py

@@ -1,5 +1,8 @@
 # Errors
 
+for item in {1}:
+    print(f"I can count to {item}!")
+
 for item in {"apples", "lemons", "water"}:  # flags in-line set literals
     print(f"I like {item}.")
 

crates/ruff_linter/src/rules/pylint/rules/iteration_over_set.rs

@@ -1,10 +1,11 @@
+use ast::ExprContext;
 use ruff_python_ast::{self as ast, Expr};
 
-use ruff_diagnostics::{Diagnostic, Violation};
+use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_text_size::Ranged;
+use ruff_text_size::{Ranged, TextRange};
 
-use crate::checkers::ast::Checker;
+use crate::{checkers::ast::Checker, registry::AsRule};
 
 /// ## What it does
 /// Checks for iterations over `set` literals.
@@ -30,11 +31,15 @@ use crate::checkers::ast::Checker;
 #[violation]
 pub struct IterationOverSet;
 
-impl Violation for IterationOverSet {
+impl AlwaysFixableViolation for IterationOverSet {
     #[derive_message_formats]
     fn message(&self) -> String {
         format!("Use a sequence type instead of a `set` when iterating over values")
     }
+
+    fn fix_title(&self) -> String {
+        format!("Use a sequence type instead of a `set` when iterating over values")
+    }
 }
 
 /// PLC0208
@@ -47,7 +52,19 @@ pub(crate) fn iteration_over_set(checker: &mut Checker, expr: &Expr) {
         return;
     }
 
-    checker
-        .diagnostics
-        .push(Diagnostic::new(IterationOverSet, expr.range()));
+    let mut diagnostic = Diagnostic::new(IterationOverSet, expr.range());
+
+    if checker.patch(diagnostic.kind.rule()) {
+        let tuple = checker.generator().expr(&Expr::Tuple(ast::ExprTuple {
+            elts: elts.clone(),
+            ctx: ExprContext::Store,
+            range: TextRange::default(),
+        }));
+        diagnostic.set_fix(Fix::safe_edit(Edit::range_replacement(
+            format!("({tuple})"),
+            expr.range(),
+        )));
+    }
+
+    checker.diagnostics.push(diagnostic);
 }

crates/ruff_linter/src/rules/pylint/snapshots/ruff_linter__rules__pylint__tests__PLC0208_iteration_over_set.py.snap

@@ -1,53 +1,127 @@
 ---
 source: crates/ruff_linter/src/rules/pylint/mod.rs
 ---
-iteration_over_set.py:3:13: PLC0208 Use a sequence type instead of a `set` when iterating over values
+iteration_over_set.py:3:13: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
   |
 1 | # Errors
 2 | 
-3 | for item in {"apples", "lemons", "water"}:  # flags in-line set literals
-  |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PLC0208
-4 |     print(f"I like {item}.")
+3 | for item in {1}:
+  |             ^^^ PLC0208
+4 |     print(f"I can count to {item}!")
   |
+  = help: Use a sequence type instead of a `set` when iterating over values
+
+ℹ Fix
+1 1 | # Errors
+2 2 | 
+3   |-for item in {1}:
+  3 |+for item in (1,):
+4 4 |     print(f"I can count to {item}!")
+5 5 | 
+6 6 | for item in {"apples", "lemons", "water"}:  # flags in-line set literals
 
-iteration_over_set.py:6:28: PLC0208 Use a sequence type instead of a `set` when iterating over values
+iteration_over_set.py:6:13: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
   |
-4 |     print(f"I like {item}.")
+4 |     print(f"I can count to {item}!")
 5 | 
-6 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
-  |                            ^^^^^^^^^ PLC0208
-7 | 
-8 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+6 | for item in {"apples", "lemons", "water"}:  # flags in-line set literals
+  |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PLC0208
+7 |     print(f"I like {item}.")
   |
+  = help: Use a sequence type instead of a `set` when iterating over values
 
-iteration_over_set.py:8:27: PLC0208 Use a sequence type instead of a `set` when iterating over values
+ℹ Fix
+3 3 | for item in {1}:
+4 4 |     print(f"I can count to {item}!")
+5 5 | 
+6   |-for item in {"apples", "lemons", "water"}:  # flags in-line set literals
+  6 |+for item in ("apples", "lemons", "water"):  # flags in-line set literals
+7 7 |     print(f"I like {item}.")
+8 8 | 
+9 9 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+
+iteration_over_set.py:9:28: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+   |
+ 7 |     print(f"I like {item}.")
+ 8 | 
+ 9 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+   |                            ^^^^^^^^^ PLC0208
+10 | 
+11 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
    |
- 6 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
- 7 | 
- 8 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+   = help: Use a sequence type instead of a `set` when iterating over values
+
+ℹ Fix
+6  6  | for item in {"apples", "lemons", "water"}:  # flags in-line set literals
+7  7  |     print(f"I like {item}.")
+8  8  | 
+9     |-numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+   9  |+numbers_list = [i for i in (1, 2, 3)]  # flags sets in list comprehensions
+10 10 | 
+11 11 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+12 12 | 
+
+iteration_over_set.py:11:27: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+   |
+ 9 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+10 | 
+11 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
    |                           ^^^^^^^^^ PLC0208
- 9 | 
-10 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+12 | 
+13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
    |
+   = help: Use a sequence type instead of a `set` when iterating over values
+
+ℹ Fix
+8  8  | 
+9  9  | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+10 10 | 
+11    |-numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+   11 |+numbers_set = {i for i in (1, 2, 3)}  # flags sets in set comprehensions
+12 12 | 
+13 13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+14 14 | 
 
-iteration_over_set.py:10:36: PLC0208 Use a sequence type instead of a `set` when iterating over values
+iteration_over_set.py:13:36: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
    |
- 8 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
- 9 | 
-10 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+11 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+12 | 
+13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
    |                                    ^^^^^^^^^ PLC0208
-11 | 
-12 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+14 | 
+15 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
    |
+   = help: Use a sequence type instead of a `set` when iterating over values
 
-iteration_over_set.py:12:27: PLC0208 Use a sequence type instead of a `set` when iterating over values
+ℹ Fix
+10 10 | 
+11 11 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+12 12 | 
+13    |-numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+   13 |+numbers_dict = {str(i): i for i in (1, 2, 3)}  # flags sets in dict comprehensions
+14 14 | 
+15 15 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+16 16 | 
+
+iteration_over_set.py:15:27: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
    |
-10 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
-11 | 
-12 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+14 | 
+15 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
    |                           ^^^^^^^^^ PLC0208
-13 | 
-14 | # Non-errors
+16 | 
+17 | # Non-errors
    |
+   = help: Use a sequence type instead of a `set` when iterating over values
+
+ℹ Fix
+12 12 | 
+13 13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+14 14 | 
+15    |-numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+   15 |+numbers_gen = (i for i in (1, 2, 3))  # flags sets in generator expressions
+16 16 | 
+17 17 | # Non-errors
+18 18 |