fix(analyzer): propagate type narrowing through break statements in loops

Author: azjezz

crates/analyzer/src/statement/loop/break.rs

@@ -87,19 +87,21 @@ impl<'ast, 'arena> Analyzable<'ast, 'arena> for Break<'arena> {
             let redefined_vars =
                 block_context.get_redefined_locals(&loop_scope.parent_context_variables, false, &mut removed_var_ids);
 
-            for (var_id, parent_type) in &loop_scope.parent_context_variables {
+            for var_id in loop_scope.parent_context_variables.keys() {
                 if !redefined_vars.contains_key(var_id) {
-                    loop_scope.possibly_redefined_loop_parent_variables.insert(
-                        *var_id,
-                        Rc::new(add_optional_union_type(
-                            (**parent_type).clone(),
-                            loop_scope
-                                .possibly_redefined_loop_parent_variables
-                                .get(var_id)
-                                .map(std::convert::AsRef::as_ref),
-                            context.codebase,
-                        )),
-                    );
+                    if let Some(current_type) = block_context.locals.get(var_id) {
+                        loop_scope.possibly_redefined_loop_parent_variables.insert(
+                            *var_id,
+                            Rc::new(add_optional_union_type(
+                                (**current_type).clone(),
+                                loop_scope
+                                    .possibly_redefined_loop_parent_variables
+                                    .get(var_id)
+                                    .map(std::convert::AsRef::as_ref),
+                                context.codebase,
+                            )),
+                        );
+                    }
                 }
             }
 

crates/analyzer/tests/cases/break_narrowing.php

@@ -5,6 +5,11 @@ function takeString(string $s): void
     takeString($s);
 }
 
+function takeInt(int $i): void
+{
+    takeInt($i);
+}
+
 function testSimpleBreakNarrowing(null|string $value): string
 {
     while (true) {
@@ -19,3 +24,18 @@ function testSimpleBreakNarrowing(null|string $value): string
 
     return $value;
 }
+
+function testBreakAfterNullCheck(null|int $value): null|int
+{
+    while (true) {
+        if ($value !== null) {
+            break;
+        }
+        $value = 0;
+        break;
+    }
+
+    takeInt($value);
+
+    return $value;
+}