#3057. Add promotion tests for if and break statements

TypeSystem/flow-analysis/reachability_break_A05_t01.dart

@@ -0,0 +1,86 @@
+// 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 Break statement: If `N` is a statement of the form `break [L];`,
+/// then:
+/// - Let `S` be the statement targeted by the `break`. If `L` is not present,
+///   this is the innermost `do`, `for`, `switch`, or `while` statement.
+///   Otherwise it is the `do`, `for`, `switch`, or `while` statement with a
+///   label matching L.
+/// - Update `break(S) = join(break(S), before(N))`.
+/// - Let `after(N) = unreachable(before(N))`.
+///
+/// @description Checks that if some type `T` is made a type of interest
+/// `before(N)` then the variable can be promoted to `T` in `after(N)`.
+/// @author sgrekhov22@gmail.com
+
+class S {}
+
+class T extends S {
+  int answer() => 42;
+}
+
+test1() {
+  S s = S();
+  for (int j = 0; j < 1; j++) {
+    if (s is T) {} // Make `T` a type of interest
+    break;
+    // Unreachable, but does support promotion.
+    s = T();
+    s.answer();
+  }
+}
+
+test2() {
+  S s = S();
+  for (var j in []) {
+    if (s is T) {}
+    break;
+    s = T();
+    s.answer();
+  }
+}
+
+test3() {
+  S s = S();
+  do {
+    if (s is T) {}
+    break;
+    s = T();
+    s.answer();
+  } while (1 > 2);
+}
+
+test4() {
+  S s = S();
+  int i = 0;
+  while (i < 1) {
+    i++;
+    if (s is T) {}
+    break;
+    s = T();
+    s.answer();
+  }
+}
+
+test5() {
+  S s = S();
+  switch (42) {
+    case 1:
+      break;
+    case 42:
+      if (s is T) {}
+      break;
+      s = T();
+      s.answer();
+  }
+}
+
+main() {
+  test1();
+  test2();
+  test3();
+  test4();
+  test5();
+}

TypeSystem/flow-analysis/reachability_break_A05_t02.dart

@@ -0,0 +1,101 @@
+// 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 Break statement: If `N` is a statement of the form `break [L];`,
+/// then:
+/// - Let `S` be the statement targeted by the `break`. If `L` is not present,
+///   this is the innermost `do`, `for`, `switch`, or `while` statement.
+///   Otherwise it is the `do`, `for`, `switch`, or `while` statement with a
+///   label matching L.
+/// - Update `break(S) = join(break(S), before(N))`.
+/// - Let `after(N) = unreachable(before(N))`.
+///
+/// @description Checks that if some type `T` is made a type of interest
+/// `before(N)` then the variable can be promoted to `T` in `after(N)`.
+/// @author sgrekhov22@gmail.com
+
+class S {}
+
+class T extends S {
+  int answer() => 42;
+}
+
+test1() {
+  S s = S();
+  L:
+  for (int j = 0; j < 1; j++) {
+    for (int j = 0; j < 1; j++) {
+      if (s is T) {} // Make `T` a type of interest
+      break L;
+      // Unreachable, but does support promotion.
+      s = T();
+      s.answer();
+    }
+  }
+}
+
+test2() {
+  S s = S();
+  L:
+  for (var i in []) {
+    for (var j in []) {
+      if (s is T) {}
+      break L;
+      s = T();
+      s.answer();
+    }
+  }
+}
+
+test3() {
+  S s = S();
+  L:
+  do {
+    do {
+      if (s is T) {}
+      break L;
+      s = T();
+      s.answer();
+    } while (1 > 2);
+  } while (1 > 2);
+}
+
+test4() {
+  S s = S();
+  int i = 0;
+  L:
+  while (i < 1) {
+    while (i < 1) {
+      i++;
+      if (s is T) {}
+      break L;
+      s = T();
+      s.answer();
+    }
+  }
+}
+
+test5() {
+  S s = S();
+  L:
+  for (;;) {
+    switch (42) {
+      case 1:
+        break;
+      case 42:
+        if (s is T) {}
+        break L;
+        s = T();
+        s.answer();
+    }
+  }
+}
+
+main() {
+  test1();
+  test2();
+  test3();
+  test4();
+  test5();
+}

TypeSystem/flow-analysis/reachability_break_A05_t03.dart

@@ -0,0 +1,101 @@
+// 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 Break statement: If `N` is a statement of the form `break [L];`,
+/// then:
+/// - Let `S` be the statement targeted by the `break`. If `L` is not present,
+///   this is the innermost `do`, `for`, `switch`, or `while` statement.
+///   Otherwise it is the `do`, `for`, `switch`, or `while` statement with a
+///   label matching L.
+/// - Update `break(S) = join(break(S), before(N))`.
+/// - Let `after(N) = unreachable(before(N))`.
+///
+/// @description Checks that if some type `T` is made a type of interest
+/// `after(N)` then the variable cannot be promoted to `T` in `before(N)`.
+/// @author sgrekhov22@gmail.com
+
+class S {}
+
+class T extends S {
+  int answer() => 42;
+}
+
+test1() {
+  S s = S();
+  for (int j = 0; j < 2; j++) {
+    s = T();
+    s.answer();
+//    ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    break;
+    // Unreachable, but does support promotion.
+    if (s is T) {} // Make `T` a type of interest
+  }
+}
+
+test2() {
+  S s = S();
+  for (var j in []) {
+    s = T();
+    s.answer();
+//    ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    break;
+    if (s is T) {}
+  }
+}
+
+test3() {
+  S s = S();
+  do {
+    s = T();
+    s.answer();
+//    ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    break;
+    if (s is T) {}
+  } while (1 > 2);
+}
+
+test4() {
+  S s = S();
+  int i = 0;
+  while (i < 2) {
+    i++;
+    s = T();
+    s.answer();
+//    ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+    break;
+    if (s is T) {}
+  }
+}
+
+test5() {
+  S s = S();
+  switch (42) {
+    case 1:
+      break;
+    case 42:
+      s = T();
+      s.answer();
+//      ^^^^^^
+// [analyzer] unspecified
+// [cfe] unspecified
+      break;
+      if (s is T) {}
+  }
+}
+
+main() {
+  print(test1);
+  print(test2);
+  print(test5);
+  print(test4);
+  print(test5);
+}