Fixed bug where classes declared in a conditional scope were not properly handled.

server/src/analyzer/scope.ts

@@ -374,7 +374,8 @@ export class Scope {
 
         if (this._parent) {
             // If our recursion is about to take us outside the scope of the current
-            // module (i.e. into a built-in scope), indicate as such with the second parameter.
+            // module (i.e. into a built-in scope), indicate as such with the second
+            // parameter.
             return this._parent._lookUpSymbolRecursiveInternal(name,
                 isOutsideCallerModule || this._scopeType === ScopeType.Module,
                 isBeyondExecutionScope || this.isIndependentlyExecutable());

server/src/analyzer/typeAnalyzer.ts

@@ -3471,6 +3471,15 @@ export class TypeAnalyzer extends ParseTreeWalker {
         let prevScope = this._currentScope;
         let newScope = AnalyzerNodeInfo.getScope(node);
         assert(newScope !== undefined);
+
+        let prevParent: Scope | undefined;
+        if (!newScope!.isIndependentlyExecutable()) {
+            // Temporary reparent the scope in case it is contained
+            // within a temporary scope.
+            prevParent = newScope!.getParent();
+            newScope!.setParent(this._currentScope);
+        }
+
         this._currentScope = newScope!;
 
         // Clear the raises/returns flags in case this wasn't our
@@ -3486,6 +3495,9 @@ export class TypeAnalyzer extends ParseTreeWalker {
         this._currentScope.clearTypeConstraints();
 
         this._currentScope = prevScope;
+        if (prevParent) {
+            newScope!.setParent(prevParent);
+        }
 
         return newScope!;
     }

server/src/tests/samples/unbound1.py

@@ -0,0 +1,19 @@
+# This sample tests the type checker's ability to determine which
+# symbols are potentially unbound.
+
+if True:
+    class X:
+        # This should generate an error because 'X' is not yet declared.
+        def foo(self) -> X:
+            return X()
+
+    a: X
+
+    class A:
+        a: X
+        b = X
+
+        def fn(self) -> X:
+            return X()
+
+

server/src/tests/typeAnalyzer.test.ts

@@ -523,3 +523,9 @@ test('UnnecessaryIsInstance1', () => {
     analysisResults = TestUtils.typeAnalyzeSampleFiles(['unnecessaryIsInstance1.py'], configOptions);
     validateResults(analysisResults, 3);
 });
+
+test('Unbound1', () => {
+    let analysisResults = TestUtils.typeAnalyzeSampleFiles(['unbound1.py']);
+
+    validateResults(analysisResults, 1);
+});