Merge ecc8834 into 1640ca7

Author: tenhobi

pkg/analyzer/lib/src/dart/resolver/flow_analysis_visitor.dart

@@ -459,7 +459,10 @@ class TypeSystemOperations
   @override
   TypeClassification classifyType(SharedTypeView<DartType> type) {
     DartType unwrapped = type.unwrapTypeView();
-    if (isSubtypeOfInternal(unwrapped, typeSystem.typeProvider.objectType)) {
+    if (type is InvalidType) {
+      return TypeClassification.potentiallyNullable;
+    } else if (isSubtypeOfInternal(
+        unwrapped, typeSystem.typeProvider.objectType)) {
       return TypeClassification.nonNullable;
     } else if (isSubtypeOfInternal(
         unwrapped, typeSystem.typeProvider.nullType)) {

pkg/analyzer/test/src/diagnostics/unnecessary_null_assert_pattern_test.dart

@@ -15,7 +15,7 @@ main() {
 
 @reflectiveTest
 class UnnecessaryNullAssertPatternTest extends PubPackageResolutionTest {
-  test_interfaceType_nonNullable() async {
+  Future<void> test_interfaceType_nonNullable() async {
     await assertErrorsInCode('''
 void f(int x) {
   if (x case var a!) {}
@@ -26,7 +26,7 @@ void f(int x) {
     ]);
   }
 
-  test_interfaceType_nullable() async {
+  Future<void> test_interfaceType_nullable() async {
     await assertErrorsInCode('''
 void f(int? x) {
   if (x case var a!) {}
@@ -36,7 +36,34 @@ void f(int? x) {
     ]);
   }
 
-  test_typeParameter_nonNullable() async {
+  Future<void> test_invalidType_nonNullable() async {
+    await assertErrorsInCode('''
+UnknownType getValue() => UnknownType();
+void f() {
+  if (getValue() case final valueX!) {
+    print(valueX);
+  }
+}
+''', [
+      error(CompileTimeErrorCode.UNDEFINED_CLASS, 0, 11),
+      error(CompileTimeErrorCode.UNDEFINED_FUNCTION, 26, 11),
+    ]);
+  }
+
+  Future<void> test_invalidType_nullable() async {
+    await assertErrorsInCode('''
+UnknownType? getValue() => null;
+void f() {
+  if (getValue() case final valueX!) {
+    print(valueX);
+  }
+}
+''', [
+      error(CompileTimeErrorCode.UNDEFINED_CLASS, 0, 11),
+    ]);
+  }
+
+  Future<void> test_typeParameter_nonNullable() async {
     await assertErrorsInCode('''
 class A<T extends num> {
   void f(T x) {
@@ -49,7 +76,7 @@ class A<T extends num> {
     ]);
   }
 
-  test_typeParameter_nullable() async {
+  Future<void> test_typeParameter_nullable() async {
     await assertErrorsInCode('''
 class A<T> {
   void f(T x) {

pkg/analyzer/test/src/diagnostics/unnecessary_null_check_pattern_test.dart

@@ -15,7 +15,7 @@ main() {
 
 @reflectiveTest
 class UnnecessaryNullCheckPatternTest extends PubPackageResolutionTest {
-  test_interfaceType_nonNullable() async {
+  Future<void> test_interfaceType_nonNullable() async {
     await assertErrorsInCode('''
 void f(int x) {
   if (x case var a?) {}
@@ -26,7 +26,7 @@ void f(int x) {
     ]);
   }
 
-  test_interfaceType_nullable() async {
+  Future<void> test_interfaceType_nullable() async {
     await assertErrorsInCode('''
 void f(int? x) {
   if (x case var a?) {}
@@ -36,7 +36,34 @@ void f(int? x) {
     ]);
   }
 
-  test_typeParameter_nonNullable() async {
+  Future<void> test_invalidType_nonNullable() async {
+    await assertErrorsInCode('''
+UnknownType getValue() => UnknownType();
+void f() {
+  if (getValue() case final valueX?) {
+    print(valueX);
+  }
+}
+''', [
+      error(CompileTimeErrorCode.UNDEFINED_CLASS, 0, 11),
+      error(CompileTimeErrorCode.UNDEFINED_FUNCTION, 26, 11),
+    ]);
+  }
+
+  Future<void> test_invalidType_nullable() async {
+    await assertErrorsInCode('''
+UnknownType? getValue() => null;
+void f() {
+  if (getValue() case final valueX?) {
+    print(valueX);
+  }
+}
+''', [
+      error(CompileTimeErrorCode.UNDEFINED_CLASS, 0, 11),
+    ]);
+  }
+
+  Future<void> test_typeParameter_nonNullable() async {
     await assertErrorsInCode('''
 class A<T extends num> {
   void f(T x) {
@@ -49,7 +76,7 @@ class A<T extends num> {
     ]);
   }
 
-  test_typeParameter_nullable() async {
+  Future<void> test_typeParameter_nullable() async {
     await assertErrorsInCode('''
 class A<T> {
   void f(T x) {