Use set bracket replacement for iteration-over-set (#8001)

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

@@ -6,6 +6,14 @@ for item in {1}:
 for item in {"apples", "lemons", "water"}:  # flags in-line set literals
     print(f"I like {item}.")
 
+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}.")
+
 numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
 
 numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions

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

@@ -1,9 +1,7 @@
-use ast::ExprContext;
-use ruff_python_ast::{self as ast, Expr};
-
 use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_text_size::{Ranged, TextRange};
+use ruff_python_ast::{self as ast, Expr};
+use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
 
@@ -38,7 +36,7 @@ impl AlwaysFixableViolation for IterationOverSet {
     }
 
     fn fix_title(&self) -> String {
-        format!("Use a sequence type instead of a `set` when iterating over values")
+        format!("Convert to `tuple`")
     }
 }
 
@@ -54,15 +52,14 @@ pub(crate) fn iteration_over_set(checker: &mut Checker, expr: &Expr) {
 
     let mut diagnostic = Diagnostic::new(IterationOverSet, expr.range());
 
-    let tuple = checker.generator().expr(&Expr::Tuple(ast::ExprTuple {
+    let tuple = if let [elt] = elts.as_slice() {
-        elts: elts.clone(),
+        let elt = checker.locator().slice(elt);
-        ctx: ExprContext::Store,
+        format!("({elt},)")
-        range: TextRange::default(),
+    } else {
-    }));
+        let set = checker.locator().slice(expr);
-    diagnostic.set_fix(Fix::safe_edit(Edit::range_replacement(
+        format!("({})", &set[1..set.len() - 1])
-        format!("({tuple})"),
+    };
-        expr.range(),
+    diagnostic.set_fix(Fix::safe_edit(Edit::range_replacement(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

@@ -9,7 +9,7 @@ iteration_over_set.py:3:13: PLC0208 [*] Use a sequence type instead of a `set` w
   |             ^^^ PLC0208
 4 |     print(f"I can count to {item}!")
   |
-  = help: Use a sequence type instead of a `set` when iterating over values
+  = help: Convert to `tuple`
 
 ℹ Fix
 1 1 | # Errors
@@ -28,7 +28,7 @@ iteration_over_set.py:6:13: PLC0208 [*] Use a sequence type instead of a `set` w
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PLC0208
 7 |     print(f"I like {item}.")
   |
-  = help: Use a sequence type instead of a `set` when iterating over values
+  = help: Convert to `tuple`
 
 ℹ Fix
 3 3 | for item in {1}:
@@ -38,90 +38,136 @@ iteration_over_set.py:6:13: PLC0208 [*] Use a sequence type instead of a `set` w
   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
+9 9 | for item in {1,}:
 
-iteration_over_set.py:9:28: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+iteration_over_set.py:9:13: 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
+ 9 | for item in {1,}:
-   |                            ^^^^^^^^^ PLC0208
+   |             ^^^^ PLC0208
-10 | 
+10 |     print(f"I can count to {item}!")
-11 | 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
+   = help: Convert to `tuple`
 
 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     |-for item in {1,}:
-   9  |+numbers_list = [i for i in (1, 2, 3)]  # flags sets in list comprehensions
+   9  |+for item in (1,):
-10 10 | 
+10 10 |     print(f"I can count to {item}!")
-11 11 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+11 11 | 
-12 12 | 
+12 12 | for item in {
 
-iteration_over_set.py:11:27: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+iteration_over_set.py:12:13: 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 |       print(f"I can count to {item}!")
-10 | 
+11 |   
-11 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+12 |   for item in {
-   |                           ^^^^^^^^^ PLC0208
+   |  _____________^
-12 | 
+13 | |     "apples", "lemons", "water"
-13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+14 | | }:  # flags in-line set literals
+   | |_^ PLC0208
+15 |       print(f"I like {item}.")
    |
-   = help: Use a sequence type instead of a `set` when iterating over values
+   = help: Convert to `tuple`
 
 ℹ Fix
-8  8  | 
+9  9  | for item in {1,}:
-9  9  | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+10 10 |     print(f"I can count to {item}!")
-10 10 | 
+11 11 | 
-11    |-numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+12    |-for item in {
-   11 |+numbers_set = {i for i in (1, 2, 3)}  # flags sets in set comprehensions
+   12 |+for item in (
-12 12 | 
+13 13 |     "apples", "lemons", "water"
-13 13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+14    |-}:  # flags in-line set literals
-14 14 | 
+   14 |+):  # flags in-line set literals
-
+15 15 |     print(f"I like {item}.")
-iteration_over_set.py:13:36: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
-   |
-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
-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
-
-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 | 
+17 17 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
 
-iteration_over_set.py:15:27: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+iteration_over_set.py:17:28: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
    |
-13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+15 |     print(f"I like {item}.")
-14 | 
-15 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
-   |                           ^^^^^^^^^ PLC0208
 16 | 
-17 | # Non-errors
+17 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+   |                            ^^^^^^^^^ PLC0208
+18 | 
+19 | 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
+   = help: Convert to `tuple`
 
 ℹ Fix
-12 12 | 
+14 14 | }:  # flags in-line set literals
-13 13 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+15 15 |     print(f"I like {item}.")
-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
+17    |-numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+   17 |+numbers_list = [i for i in (1, 2, 3)]  # flags sets in list comprehensions
 18 18 | 
+19 19 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+20 20 | 
+
+iteration_over_set.py:19:27: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+   |
+17 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+18 | 
+19 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+   |                           ^^^^^^^^^ PLC0208
+20 | 
+21 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+   |
+   = help: Convert to `tuple`
+
+ℹ Fix
+16 16 | 
+17 17 | numbers_list = [i for i in {1, 2, 3}]  # flags sets in list comprehensions
+18 18 | 
+19    |-numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+   19 |+numbers_set = {i for i in (1, 2, 3)}  # flags sets in set comprehensions
+20 20 | 
+21 21 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+22 22 | 
+
+iteration_over_set.py:21:36: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+   |
+19 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+20 | 
+21 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+   |                                    ^^^^^^^^^ PLC0208
+22 | 
+23 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+   |
+   = help: Convert to `tuple`
+
+ℹ Fix
+18 18 | 
+19 19 | numbers_set = {i for i in {1, 2, 3}}  # flags sets in set comprehensions
+20 20 | 
+21    |-numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+   21 |+numbers_dict = {str(i): i for i in (1, 2, 3)}  # flags sets in dict comprehensions
+22 22 | 
+23 23 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+24 24 | 
+
+iteration_over_set.py:23:27: PLC0208 [*] Use a sequence type instead of a `set` when iterating over values
+   |
+21 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+22 | 
+23 | numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+   |                           ^^^^^^^^^ PLC0208
+24 | 
+25 | # Non-errors
+   |
+   = help: Convert to `tuple`
+
+ℹ Fix
+20 20 | 
+21 21 | numbers_dict = {str(i): i for i in {1, 2, 3}}  # flags sets in dict comprehensions
+22 22 | 
+23    |-numbers_gen = (i for i in {1, 2, 3})  # flags sets in generator expressions
+   23 |+numbers_gen = (i for i in (1, 2, 3))  # flags sets in generator expressions
+24 24 | 
+25 25 | # Non-errors
+26 26 |