#3057. Add null-aware method invocation tests

TypeSystem/flow-analysis/reachability_A24_t01.dart

@@ -0,0 +1,38 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion Null-aware method invocation
+/// For now (April, 2025) the flow-analysis feature specification does not
+/// specify the analysis of Null-aware method invocation.
+///
+/// @description Checks that flow analysis doesn't promote to `Null`.
+/// @author [email protected]
+
+// SharedOptions=--enable-experiment=sound-flow-analysis
+
+class C {
+  void foo(int x) {}
+}
+
+test1(C? c) {
+  late int i;
+  if (c == null) { // This doesn't promote `c` to `Null`
+    c?.foo(i = 42);
+  }
+  i; // Possibly assigned
+}
+
+test2(C? c) {
+  late int i;
+  if (c == null) {
+    c?..foo(i = 0)
+      ..foo(0);
+  }
+  i;
+}
+
+main() {
+  print(test1);
+  print(test2);
+}

TypeSystem/flow-analysis/reachability_A24_t02.dart

@@ -0,0 +1,45 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion Null-aware method invocation
+/// For now (April, 2025) the flow-analysis feature specification does not
+/// specify the analysis of Null-aware method invocation.
+///
+/// @description Checks that is come variable is promoted to non-nullable then
+/// null-aware method invocation is treated as a regular invocation.
+/// @author [email protected]
+
+// SharedOptions=--enable-experiment=sound-flow-analysis
+
+class C {
+  void foo(int x) {}
+}
+
+test1(C? c) {
+  int i;
+  if (c != null) {
+    c?.foo(i = 42); // ignore: invalid_null_aware_operator
+  } else {
+    i = 0;
+  }
+  i; // Definitely assigned
+}
+
+test2(C? c) {
+  int i;
+  if (c != null) {
+    c?..foo(0)  // ignore: invalid_null_aware_operator
+      ..foo(i = 42);
+  } else {
+    i = 1;
+  }
+  i; // Definitely assigned
+}
+
+main() {
+  test1(C());
+  test1(null);
+  test2(C());
+  test2(null);
+}

TypeSystem/flow-analysis/reachability_A24_t03.dart

@@ -0,0 +1,53 @@
+// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion Null-aware method invocation
+/// For now (April, 2025) the flow-analysis feature specification does not
+/// specify the analysis of Null-aware method invocation.
+///
+/// @description Checks reachability after method call. Test return type `Never`
+/// @author [email protected]
+
+// SharedOptions=--enable-experiment=sound-flow-analysis
+
+class C {
+  Never m1() => throw "Exception";
+}
+
+test1(C? c) {
+  try {
+    late int i;
+    if (c != null) {
+      c?.m1();    // ignore: invalid_null_aware_operator
+      i = 42;     // This is dead code, which leaves `i` definitely unassigned.
+    }
+    i; // Definitely unassigned.
+//  ^
+// [analyzer] unspecified
+// [cfe] unspecified
+  } catch (_) {
+  }
+}
+
+test2(C? c) {
+  try {
+    late int i;
+    if (c != null) {
+      c?..m1(); // ignore: invalid_null_aware_operator
+      i = 42;
+    }
+    i;
+//  ^
+// [analyzer] unspecified
+// [cfe] unspecified
+  } catch (_) {
+  }
+}
+
+main() {
+  test1(C());
+  test1(null);
+  test2(C());
+  test2(null);
+}

TypeSystem/flow-analysis/reachability_A24_t04.dart

@@ -0,0 +1,47 @@
+// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion Null-aware method invocation
+/// For now (April, 2025) the flow-analysis feature specification does not
+/// specify the analysis of Null-aware method invocation.
+///
+/// @description Checks reachability after method call. Test return type `Never`
+/// @author [email protected]
+
+// SharedOptions=--enable-experiment=sound-flow-analysis
+
+class C {
+  Never m1() => throw "Exception";
+}
+
+test1(C? c) {
+  try {
+    late int i;
+    if (c == null) {  // This doesn't promote `c` to `Null`
+      c?.m1();
+      i = 42;
+    }
+    i; // Possibly assigned
+  } catch (_) {
+  }
+}
+
+test2(C? c) {
+  try {
+    late int i;
+    if (c == null) {
+      c?..m1();
+      i = 42;
+    }
+    i;
+  } catch (_) {
+  }
+}
+
+main() {
+  test1(C());
+  test1(null);
+  test2(C());
+  test2(null);
+}

TypeSystem/flow-analysis/reachability_A24_t05.dart

@@ -0,0 +1,46 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion Null-aware method invocation
+/// For now (April, 2025) the flow-analysis feature specification does not
+/// specify the analysis of Null-aware method invocation.
+///
+/// @description Checks that code after type `Never` is unreachable.
+/// @author [email protected]
+/// @issue 54820
+
+// SharedOptions=--enable-experiment=sound-flow-analysis
+
+class C {
+  Never? get foo => throw "Exception";
+}
+
+test1() {
+  C c = C();
+  late int i;
+  if (1 > 2) {
+    c.foo?.bar(i = 42);  // ignore: receiver_of_type_never, dead_code
+  }
+  i; // Definitely unassigned
+//^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+test2() {
+  C c = C();
+  late int i;
+  if (1 > 2) {
+    c.foo?..bar(i = 0);  // ignore: receiver_of_type_never, dead_code
+  }
+  i;
+//^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(test1);
+  print(test2);
+}