[refurb] Add coverage of set and frozenset calls (FURB171) (#18035)

## Summary

Adds coverage of using set(...) in addition to `{...} in
SingleItemMembershipTest.

Fixes #15792
(and replaces the old PR #15793)

<!-- What's the purpose of the change? What does it do, and why? -->

## Test Plan

Updated unit test and snapshot.

Steps to reproduce are in the issue linked above.

<!-- How was it tested? -->

Author: naslundx

crates/ruff_linter/resources/test/fixtures/refurb/FURB171.py renamed to crates/ruff_linter/resources/test/fixtures/refurb/FURB171_0.py

@@ -0,0 +1,53 @@
+# Errors.
+
+if 1 in set([1]):
+    print("Single-element set")
+
+if 1 in set((1,)):
+    print("Single-element set")
+
+if 1 in set({1}):
+    print("Single-element set")
+
+if 1 in frozenset([1]):
+    print("Single-element set")
+
+if 1 in frozenset((1,)):
+    print("Single-element set")
+
+if 1 in frozenset({1}):
+    print("Single-element set")
+
+if 1 in set(set([1])):
+    print('Recursive solution')
+
+
+
+# Non-errors.
+
+if 1 in set((1, 2)):
+    pass
+
+if 1 in set([1, 2]):
+    pass
+
+if 1 in set({1, 2}):
+    pass
+
+if 1 in frozenset((1, 2)):
+    pass
+
+if 1 in frozenset([1, 2]):
+    pass
+
+if 1 in frozenset({1, 2}):
+    pass
+
+if 1 in set(1,):
+    pass
+
+if 1 in set(1,2):
+    pass
+
+if 1 in set((x for x in range(2))):
+    pass

crates/ruff_linter/resources/test/fixtures/refurb/FURB171_1.py

@@ -35,7 +35,8 @@ mod tests {
     #[test_case(Rule::UnnecessaryFromFloat, Path::new("FURB164.py"))]
     #[test_case(Rule::PrintEmptyString, Path::new("FURB105.py"))]
     #[test_case(Rule::ImplicitCwd, Path::new("FURB177.py"))]
-    #[test_case(Rule::SingleItemMembershipTest, Path::new("FURB171.py"))]
+    #[test_case(Rule::SingleItemMembershipTest, Path::new("FURB171_0.py"))]
+    #[test_case(Rule::SingleItemMembershipTest, Path::new("FURB171_1.py"))]
     #[test_case(Rule::BitCount, Path::new("FURB161.py"))]
     #[test_case(Rule::IntOnSlicedStr, Path::new("FURB166.py"))]
     #[test_case(Rule::RegexFlagAlias, Path::new("FURB167.py"))]

crates/ruff_linter/src/rules/refurb/mod.rs

@@ -1,6 +1,7 @@
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::helpers::generate_comparison;
 use ruff_python_ast::{self as ast, CmpOp, Expr, ExprStringLiteral};
+use ruff_python_semantic::SemanticModel;
 use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
@@ -78,8 +79,8 @@ pub(crate) fn single_item_membership_test(
         _ => return,
     };
 
-    // Check if the right-hand side is a single-item object.
-    let Some(item) = single_item(right) else {
+    // Check if the right-hand side is a single-item object
+    let Some(item) = single_item(right, checker.semantic()) else {
         return;
     };
 
@@ -115,7 +116,7 @@ pub(crate) fn single_item_membership_test(
 
 /// Return the single item wrapped in `Some` if the expression contains a single
 /// item, otherwise return `None`.
-fn single_item(expr: &Expr) -> Option<&Expr> {
+fn single_item<'a>(expr: &'a Expr, semantic: &'a SemanticModel) -> Option<&'a Expr> {
     match expr {
         Expr::List(ast::ExprList { elts, .. })
         | Expr::Tuple(ast::ExprTuple { elts, .. })
@@ -124,6 +125,19 @@ fn single_item(expr: &Expr) -> Option<&Expr> {
             [item] => Some(item),
             _ => None,
         },
+        Expr::Call(ast::ExprCall {
+            func,
+            arguments,
+            range: _,
+        }) => {
+            if arguments.len() != 1 || !is_set_method(func, semantic) {
+                return None;
+            }
+
+            arguments
+                .find_positional(0)
+                .and_then(|arg| single_item(arg, semantic))
+        }
         string_expr @ Expr::StringLiteral(ExprStringLiteral { value: string, .. })
             if string.chars().count() == 1 =>
         {
@@ -133,6 +147,12 @@ fn single_item(expr: &Expr) -> Option<&Expr> {
     }
 }
 
+fn is_set_method(func: &Expr, semantic: &SemanticModel) -> bool {
+    ["set", "frozenset"]
+        .iter()
+        .any(|s| semantic.match_builtin_expr(func, s))
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 enum MembershipTest {
     /// Ex) `1 in [1]`

crates/ruff_linter/src/rules/refurb/rules/single_item_membership_test.rs

@@ -1,7 +1,7 @@
 ---
 source: crates/ruff_linter/src/rules/refurb/mod.rs
 ---
-FURB171.py:3:4: FURB171 [*] Membership test against single-item container
+FURB171_0.py:3:4: FURB171 [*] Membership test against single-item container
   |
 1 | # Errors.
 2 |
@@ -20,7 +20,7 @@ FURB171.py:3:4: FURB171 [*] Membership test against single-item container
 5 5 | 
 6 6 | if 1 in [1]:
 
-FURB171.py:6:4: FURB171 [*] Membership test against single-item container
+FURB171_0.py:6:4: FURB171 [*] Membership test against single-item container
   |
 4 |     print("Single-element tuple")
 5 |
@@ -40,7 +40,7 @@ FURB171.py:6:4: FURB171 [*] Membership test against single-item container
 8 8 | 
 9 9 | if 1 in {1}:
 
-FURB171.py:9:4: FURB171 [*] Membership test against single-item container
+FURB171_0.py:9:4: FURB171 [*] Membership test against single-item container
    |
  7 |     print("Single-element list")
  8 |
@@ -60,7 +60,7 @@ FURB171.py:9:4: FURB171 [*] Membership test against single-item container
 11 11 | 
 12 12 | if "a" in "a":
 
-FURB171.py:12:4: FURB171 [*] Membership test against single-item container
+FURB171_0.py:12:4: FURB171 [*] Membership test against single-item container
    |
 10 |     print("Single-element set")
 11 |
@@ -80,7 +80,7 @@ FURB171.py:12:4: FURB171 [*] Membership test against single-item container
 14 14 | 
 15 15 | if 1 not in (1,):
 
-FURB171.py:15:4: FURB171 [*] Membership test against single-item container
+FURB171_0.py:15:4: FURB171 [*] Membership test against single-item container
    |
 13 |     print("Single-element string")
 14 |
@@ -100,7 +100,7 @@ FURB171.py:15:4: FURB171 [*] Membership test against single-item container
 17 17 | 
 18 18 | if not 1 in (1,):
 
-FURB171.py:18:8: FURB171 [*] Membership test against single-item container
+FURB171_0.py:18:8: FURB171 [*] Membership test against single-item container
    |
 16 |     print("Check `not in` membership test")
 17 |
@@ -120,7 +120,7 @@ FURB171.py:18:8: FURB171 [*] Membership test against single-item container
 20 20 | 
 21 21 | # Non-errors.
 
-FURB171.py:52:5: FURB171 [*] Membership test against single-item container
+FURB171_0.py:52:5: FURB171 [*] Membership test against single-item container
    |
 51 |   # https://github.com/astral-sh/ruff/issues/10063
 52 |   _ = a in (
@@ -147,7 +147,7 @@ FURB171.py:52:5: FURB171 [*] Membership test against single-item container
 57 54 | _ = a in (  # Foo1
 58 55 |     (  # Foo2
 
-FURB171.py:57:5: FURB171 [*] Membership test against single-item container
+FURB171_0.py:57:5: FURB171 [*] Membership test against single-item container
    |
 55 |   )
 56 |
@@ -199,7 +199,7 @@ FURB171.py:57:5: FURB171 [*] Membership test against single-item container
 74 63 | foo = (
 75 64 |     lorem()
 
-FURB171.py:77:28: FURB171 [*] Membership test against single-item container
+FURB171_0.py:77:28: FURB171 [*] Membership test against single-item container
    |
 75 |       lorem()
 76 |           .ipsum()
@@ -228,7 +228,7 @@ FURB171.py:77:28: FURB171 [*] Membership test against single-item container
 83 79 | 
 84 80 | foo = (
 
-FURB171.py:87:28: FURB171 [*] Membership test against single-item container
+FURB171_0.py:87:28: FURB171 [*] Membership test against single-item container
    |
 85 |       lorem()
 86 |           .ipsum()
@@ -262,7 +262,7 @@ FURB171.py:87:28: FURB171 [*] Membership test against single-item container
 95 93 | 
 96 94 | foo = lorem() \
 
-FURB171.py:98:24: FURB171 [*] Membership test against single-item container
+FURB171_0.py:98:24: FURB171 [*] Membership test against single-item container
     |
  96 |   foo = lorem() \
  97 |       .ipsum() \
@@ -292,7 +292,7 @@ FURB171.py:98:24: FURB171 [*] Membership test against single-item container
 104 100 | def _():
 105 101 |     if foo not \
 
-FURB171.py:105:8: FURB171 [*] Membership test against single-item container
+FURB171_0.py:105:8: FURB171 [*] Membership test against single-item container
     |
 104 |   def _():
 105 |       if foo not \
@@ -323,7 +323,7 @@ FURB171.py:105:8: FURB171 [*] Membership test against single-item container
 112 107 | def _():
 113 108 |     if foo not \
 
-FURB171.py:113:8: FURB171 [*] Membership test against single-item container
+FURB171_0.py:113:8: FURB171 [*] Membership test against single-item container
     |
 112 |   def _():
 113 |       if foo not \

crates/ruff_linter/src/rules/refurb/snapshots/ruff_linter__rules__refurb__tests__FURB171_FURB171.py.snap renamed to crates/ruff_linter/src/rules/refurb/snapshots/ruff_linter__rules__refurb__tests__FURB171_FURB171_0.py.snap

@@ -0,0 +1,141 @@
+---
+source: crates/ruff_linter/src/rules/refurb/mod.rs
+---
+FURB171_1.py:3:4: FURB171 [*] Membership test against single-item container
+  |
+1 | # Errors.
+2 |
+3 | if 1 in set([1]):
+  |    ^^^^^^^^^^^^^ FURB171
+4 |     print("Single-element set")
+  |
+  = help: Convert to equality test
+
+ℹ Safe fix
+1 1 | # Errors.
+2 2 | 
+3   |-if 1 in set([1]):
+  3 |+if 1 == 1:
+4 4 |     print("Single-element set")
+5 5 | 
+6 6 | if 1 in set((1,)):
+
+FURB171_1.py:6:4: FURB171 [*] Membership test against single-item container
+  |
+4 |     print("Single-element set")
+5 |
+6 | if 1 in set((1,)):
+  |    ^^^^^^^^^^^^^^ FURB171
+7 |     print("Single-element set")
+  |
+  = help: Convert to equality test
+
+ℹ Safe fix
+3 3 | if 1 in set([1]):
+4 4 |     print("Single-element set")
+5 5 | 
+6   |-if 1 in set((1,)):
+  6 |+if 1 == 1:
+7 7 |     print("Single-element set")
+8 8 | 
+9 9 | if 1 in set({1}):
+
+FURB171_1.py:9:4: FURB171 [*] Membership test against single-item container
+   |
+ 7 |     print("Single-element set")
+ 8 |
+ 9 | if 1 in set({1}):
+   |    ^^^^^^^^^^^^^ FURB171
+10 |     print("Single-element set")
+   |
+   = help: Convert to equality test
+
+ℹ Safe fix
+6  6  | if 1 in set((1,)):
+7  7  |     print("Single-element set")
+8  8  | 
+9     |-if 1 in set({1}):
+   9  |+if 1 == 1:
+10 10 |     print("Single-element set")
+11 11 | 
+12 12 | if 1 in frozenset([1]):
+
+FURB171_1.py:12:4: FURB171 [*] Membership test against single-item container
+   |
+10 |     print("Single-element set")
+11 |
+12 | if 1 in frozenset([1]):
+   |    ^^^^^^^^^^^^^^^^^^^ FURB171
+13 |     print("Single-element set")
+   |
+   = help: Convert to equality test
+
+ℹ Safe fix
+9  9  | if 1 in set({1}):
+10 10 |     print("Single-element set")
+11 11 | 
+12    |-if 1 in frozenset([1]):
+   12 |+if 1 == 1:
+13 13 |     print("Single-element set")
+14 14 | 
+15 15 | if 1 in frozenset((1,)):
+
+FURB171_1.py:15:4: FURB171 [*] Membership test against single-item container
+   |
+13 |     print("Single-element set")
+14 |
+15 | if 1 in frozenset((1,)):
+   |    ^^^^^^^^^^^^^^^^^^^^ FURB171
+16 |     print("Single-element set")
+   |
+   = help: Convert to equality test
+
+ℹ Safe fix
+12 12 | if 1 in frozenset([1]):
+13 13 |     print("Single-element set")
+14 14 | 
+15    |-if 1 in frozenset((1,)):
+   15 |+if 1 == 1:
+16 16 |     print("Single-element set")
+17 17 | 
+18 18 | if 1 in frozenset({1}):
+
+FURB171_1.py:18:4: FURB171 [*] Membership test against single-item container
+   |
+16 |     print("Single-element set")
+17 |
+18 | if 1 in frozenset({1}):
+   |    ^^^^^^^^^^^^^^^^^^^ FURB171
+19 |     print("Single-element set")
+   |
+   = help: Convert to equality test
+
+ℹ Safe fix
+15 15 | if 1 in frozenset((1,)):
+16 16 |     print("Single-element set")
+17 17 | 
+18    |-if 1 in frozenset({1}):
+   18 |+if 1 == 1:
+19 19 |     print("Single-element set")
+20 20 | 
+21 21 | if 1 in set(set([1])):
+
+FURB171_1.py:21:4: FURB171 [*] Membership test against single-item container
+   |
+19 |     print("Single-element set")
+20 |
+21 | if 1 in set(set([1])):
+   |    ^^^^^^^^^^^^^^^^^^ FURB171
+22 |     print('Recursive solution')
+   |
+   = help: Convert to equality test
+
+ℹ Safe fix
+18 18 | if 1 in frozenset({1}):
+19 19 |     print("Single-element set")
+20 20 | 
+21    |-if 1 in set(set([1])):
+   21 |+if 1 == 1:
+22 22 |     print('Recursive solution')
+23 23 | 
+24 24 |