Migrate language_2/lazy to NNBD.

Change-Id: Icd7ea40455f207eca1dc817ff86823cfabed3de0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/149042
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Leaf Petersen <leafp@google.com>

tests/language/lazy/map_test.dart

@@ -0,0 +1,10 @@
+// Copyright (c) 2012, 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.
+
+import "package:expect/expect.dart";
+
+var data = {'a': 'a'};
+main() {
+  Expect.equals('a', data['a']);
+}

tests/language/lazy/static2_test.dart

@@ -0,0 +1,12 @@
+// Copyright (c) 2012, 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.
+
+import "package:expect/expect.dart";
+
+final x = (int t) => t + 1;
+
+main() {
+  Expect.equals(499, x(498));
+  Expect.equals(42, x(41));
+}

tests/language/lazy/static3_test.dart

@@ -0,0 +1,78 @@
+// Copyright (c) 2012, 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.
+
+import "package:expect/expect.dart";
+
+final x = foo();
+var x2 = foo2();
+var x3 = foo3();
+var x4 = foo4();
+var x5 = foo5();
+final x6 = foo6();
+
+// Don't allow unlimited recursion to overflow the stack.
+var x7Depth = 0;
+int x7 = (++x7Depth > 10) ? x7Depth : x7 + 1;
+
+foo() {
+  throw "interrupt initialization";
+}
+
+foo2() {
+  x2 = 499;
+  throw "interrupt initialization";
+}
+
+// Don't allow unlimited recursion to overflow the stack.
+var foo3Depth = 0;
+foo3() => (++foo3Depth > 10) ? foo3Depth : x3 + 1;
+
+foo4() {
+  x4 = 498;
+  x4 = x4 + 1;
+  return x4;
+}
+
+foo5() {
+  x5 = 498;
+  x5 = x5 + 1;
+}
+
+foo6() {
+  try {
+    return x5 + 1;
+  } catch (e) {
+    return 499;
+  }
+}
+
+fib(x) {
+  if (x is! int) return 0;
+  if (x < 2) return x;
+  return fib(x - 1) + fib(x - 2);
+}
+
+main() {
+  // If an initializer throws, then accessing it again re-evaluates the
+  // initializer.
+  Expect.throws(() => fib(x), (e) => e == "interrupt initialization");
+  Expect.throws(() => fib(x), (e) => e == "interrupt initialization");
+  Expect.throws(() => fib(x), (e) => e == "interrupt initialization");
+
+  Expect.throws(() => fib(x2), (e) => e == "interrupt initialization");
+  // The store happened before the throw, so is there now.
+  Expect.equals(499, x2);
+
+  // This value means that the initializer did fully call itself recursively.
+  Expect.equals(21, x3);
+
+  Expect.equals(499, x4);
+
+  Expect.equals(null, x5);
+
+  Expect.equals(499, x6);
+
+  // This value means that the initializer did fully call itself recursively.
+  Expect.equals(21, x7);
+}

tests/language/lazy/static4_test.dart

@@ -0,0 +1,23 @@
+// Copyright (c) 2012, 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.
+
+import "package:expect/expect.dart";
+
+final x = foo(499);
+final y = foo(41) + 1;
+
+final t = bar(499);
+final u = bar(41) + 1;
+final v = bar("some string");
+
+foo(x) => x; // The return type will always be int.
+bar(x) => x; // The return type varies and can be int or String.
+
+main() {
+  Expect.equals(499, x);
+  Expect.equals(42, y);
+  Expect.equals(499, t);
+  Expect.equals(42, u);
+  Expect.equals("some string", v);
+}

tests/language/lazy/static5_test.dart

@@ -0,0 +1,12 @@
+// Copyright (c) 2012, 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.
+
+import "package:expect/expect.dart";
+
+final x = (int t) => (int u) => t + u;
+
+main() {
+  Expect.equals(499, x(498)(1));
+  Expect.equals(42, x(39)(3));
+}

tests/language/lazy/static6_src.dart

@@ -0,0 +1,28 @@
+// Copyright (c) 2012, 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.
+
+/*
+ * A lot of comments to make sure that the lazy initialization code has a
+ * position that does not fit into lazy_static6_test.dart file.
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ ******************************************************************************
+ */
+part of lazy_static6_test;
+
+final x = (int t) => (int u) => t + u;
+
+main() {
+  Expect.equals(499, x(498)(1));
+  Expect.equals(42, x(39)(3));
+}

tests/language/lazy/static6_test.dart

@@ -0,0 +1,7 @@
+// Copyright (c) 2012, 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.
+library lazy_static6_test;
+
+import "package:expect/expect.dart";
+part "static6_src.dart";

tests/language/lazy/static7_test.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2015, 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.
+
+import "package:expect/expect.dart";
+
+var sideEffect = 0;
+int x = (() {
+  sideEffect++;
+  return 499;
+})();
+
+main() {
+  if (new DateTime.now().day >= -1) {
+    x = 42;
+  }
+  Expect.equals(42, x);
+  Expect.equals(0, sideEffect);
+}

tests/language/lazy/static8_test.dart

@@ -0,0 +1,76 @@
+// Copyright (c) 2017, 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.
+
+import "package:expect/expect.dart";
+
+// Test re-entrant initializer - calls throw StackOverflowError.
+
+var trace;
+
+final foo = bar;
+
+var recursionDepth = 0;
+
+get bar {
+  if (recursionDepth > 3) throw "recursed";
+  recursionDepth++;
+
+  trace.add(recursionDepth);
+  try {
+    return foo ?? 1;
+  } catch (e) {
+    trace.add(e);
+  }
+
+  return 42;
+}
+
+void testTopLevel() {
+  trace = [];
+  recursionDepth = 0;
+  var result = foo;
+  Expect.equals(42, result);
+  Expect.equals('1,2,3,4,recursed', trace.join(','));
+  trace = [];
+  recursionDepth = 0;
+  result = foo;
+  Expect.equals(42, result);
+  Expect.equals('', trace.join(','));
+}
+
+class X {
+  static final foo = X.bar;
+
+  static get bar {
+    if (recursionDepth > 3) throw "recursed";
+    recursionDepth++;
+
+    trace.add(recursionDepth);
+    try {
+      return foo ?? 1;
+    } catch (e) {
+      trace.add(e);
+    }
+
+    return 49;
+  }
+}
+
+void testClassStatic() {
+  trace = [];
+  recursionDepth = 0;
+  var result = X.foo;
+  Expect.equals(49, result);
+  Expect.equals('1,2,3,4,recursed', trace.join(','));
+  trace = [];
+  recursionDepth = 0;
+  result = X.foo;
+  Expect.equals(49, result);
+  Expect.equals('', trace.join(','));
+}
+
+main() {
+  testTopLevel();
+  testClassStatic();
+}

tests/language/lazy/static_test.dart

@@ -0,0 +1,50 @@
+// Copyright (c) 2012, 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.
+
+import "package:expect/expect.dart";
+
+final x = foo();
+final y = y2(y3);
+final y2 = incrementCreator();
+final y3 = fib(5);
+
+foo() => 499;
+
+incrementCreator() => (x) => x + 1;
+fib(x) {
+  if (x < 2) return x;
+  return fib(x - 1) + fib(x - 2);
+}
+
+var count = 0;
+sideEffect() => count++;
+
+final t = sideEffect();
+var t2 = sideEffect();
+
+class A {
+  static final a = toto();
+  static final b = b2(b3);
+  static final b2 = decrementCreator();
+  static final b3 = fact(5);
+
+  static toto() => 666;
+
+  static decrementCreator() => (x) => x - 1;
+  static fact(x) {
+    if (x <= 1) return x;
+    return x * fact(x - 1);
+  }
+}
+
+main() {
+  Expect.equals(499, x);
+  Expect.equals(6, y);
+  Expect.equals(666, A.a);
+  Expect.equals(119, A.b);
+  Expect.equals(0, t);
+  t2 = 499;
+  Expect.equals(499, t2);
+  Expect.equals(1, count);
+}

tests/language/lazy/throwing_variable_test.dart

@@ -0,0 +1,25 @@
+// Copyright (c) 2013, 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.
+
+// Test that engines will not infer that [a] is always of type int.
+import 'package:expect/expect.dart';
+
+var a = foo();
+
+foo() {
+  () => 42;
+  if (true) throw 'Sorry';
+  return 42;
+}
+
+main() {
+  try {
+    a;
+  } catch (e) {
+    // Ignore.
+  }
+  Expect.throws(() {
+    if (a is num) throw 'Test failed';
+  }, (error) => error == 'Sorry');
+}