fixup! Support mutually exclusive branches for B031 (#3844)

crates/ruff/resources/test/fixtures/flake8_bugbear/B031.py

@@ -78,6 +78,13 @@ def collect_shop_items(shopper, items):
     for shopper in shoppers:
         collect_shop_items(shopper, section_items)  # B031
 
+for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
+    if _section == "greens":
+        collect_shop_items(shopper, section_items)
+    else:
+        collect_shop_items(shopper, section_items)
+        collect_shop_items(shopper, section_items)  # B031
+
 for _section, section_items in itertools.groupby(items, key=lambda p: p[1]):
     # Mutually exclusive branches shouldn't trigger the warning
     if _section == "greens":

crates/ruff/src/rules/flake8_bugbear/rules/reuse_of_groupby_generator.rs

@@ -153,10 +153,9 @@ where
                     self.counter_stack.last_mut().unwrap().push(0);
                 }
 
-                let has_else = !is_if_arm
-                    && orelse
-                        .first()
-                        .map_or(false, |expr| !matches!(expr.node, StmtKind::If { .. }));
+                let has_else = orelse
+                    .first()
+                    .map_or(false, |expr| !matches!(expr.node, StmtKind::If { .. }));
 
                 self.parent_ifs.push(stmt);
                 if has_else {

crates/ruff/src/rules/flake8_bugbear/snapshots/ruff__rules__flake8_bugbear__tests__B031_B031.py.snap

@@ -107,9 +107,23 @@ expression: diagnostics
     fixable: false
   location:
     row: 86
-    column: 40
+    column: 36
   end_location:
     row: 86
+    column: 49
+  fix:
+    edits: []
+  parent: ~
+- kind:
+    name: ReuseOfGroupbyGenerator
+    body: "Using the generator returned from `itertools.groupby()` more than once will do nothing on the second usage"
+    suggestion: ~
+    fixable: false
+  location:
+    row: 93
+    column: 40
+  end_location:
+    row: 93
     column: 53
   fix:
     edits: []
@@ -120,10 +134,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 88
+    row: 95
     column: 40
   end_location:
-    row: 88
+    row: 95
     column: 53
   fix:
     edits: []
@@ -134,10 +148,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 90
+    row: 97
     column: 40
   end_location:
-    row: 90
+    row: 97
     column: 53
   fix:
     edits: []
@@ -148,10 +162,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 91
+    row: 98
     column: 36
   end_location:
-    row: 91
+    row: 98
     column: 49
   fix:
     edits: []
@@ -162,10 +176,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 98
+    row: 105
     column: 48
   end_location:
-    row: 98
+    row: 105
     column: 61
   fix:
     edits: []
@@ -176,10 +190,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 104
+    row: 111
     column: 32
   end_location:
-    row: 104
+    row: 111
     column: 45
   fix:
     edits: []
@@ -190,10 +204,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 113
+    row: 120
     column: 48
   end_location:
-    row: 113
+    row: 120
     column: 61
   fix:
     edits: []
@@ -204,10 +218,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 115
+    row: 122
     column: 48
   end_location:
-    row: 115
+    row: 122
     column: 61
   fix:
     edits: []
@@ -218,10 +232,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 118
+    row: 125
     column: 40
   end_location:
-    row: 118
+    row: 125
     column: 53
   fix:
     edits: []
@@ -232,10 +246,10 @@ expression: diagnostics
     suggestion: ~
     fixable: false
   location:
-    row: 122
+    row: 129
     column: 32
   end_location:
-    row: 122
+    row: 129
     column: 45
   fix:
     edits: []