Rename is{Strong,Weak}Mode to has{Sound,Unsound}NullSafety

Change-Id: If3912d75c5f89a741299b2fae4299d01ac928eec
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/170424
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Reviewed-by: Michael Thomsen <mit@google.com>
Reviewed-by: Mayank Patke <fishythefish@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>

pkg/expect/lib/expect.dart

@@ -10,11 +10,11 @@ library expect;
 
 import 'package:meta/meta.dart';
 
-/// Whether the program is running with weak null safety checking.
-bool get isWeakMode => const <Null>[] is List<Object>;
+/// Whether the program is running without sound null safety.
+bool get hasUnsoundNullSafety => const <Null>[] is List<Object>;
 
-/// Whether the program is running with strong null safety checking.
-bool get isStrongMode => !isWeakMode;
+/// Whether the program is running with sound null safety.
+bool get hasSoundNullSafety => !hasUnsoundNullSafety;
 
 /**
  * Expect is used for tests that do not want to make use of the
@@ -620,11 +620,11 @@ class Expect {
 
   /// Checks that [f] throws an appropriate error on a null argument.
   ///
-  /// In strong mode, this is expected to be a [TypeError] when casting the
-  /// `null` to some non-nullable type. In weak mode, that cast is ignored and
-  /// some later explicit validation should handle it and [ArgumentError].
+  /// With sound null safety, this is expected to be a [TypeError] when casting
+  /// the `null` to some non-nullable type. In weak mode, that cast is ignored
+  /// and some later explicit validation should handle it and [ArgumentError].
   static void throwsNullCheckError(void f()) {
-    if (isStrongMode) {
+    if (hasSoundNullSafety) {
       throwsTypeError(f);
     } else {
       throwsArgumentError(f);

pkg/expect/test/nnbd_mode_test.dart

@@ -14,6 +14,6 @@ final bool strong = () {
 }();
 
 void main() {
-  Expect.equals(strong, isStrongMode);
-  Expect.equals(!strong, isWeakMode);
+  Expect.equals(strong, hasSoundNullSafety);
+  Expect.equals(!strong, hasUnsoundNullSafety);
 }

runtime/tests/vm/dart/error_messages_in_null_checks_test.dart

@@ -89,7 +89,7 @@ main(List<String> args) {
 
   Expect.throws(
       () => 9.81 - doubleNull,
-      (e) => isWeakMode
+      (e) => hasUnsoundNullSafety
           ? (e is NoSuchMethodError &&
               // If '-' is specialized.
               (e.toString().startsWith(

runtime/tests/vm/dart/null_checks_with_dwarf_stack_traces_test.dart

@@ -52,8 +52,10 @@ main(List<String> args) {
 
   Expect.throws(() => doubleNull + 2.17, (e) => e is NoSuchMethodError);
 
-  Expect.throws(() => 9.81 - doubleNull,
-      (e) => isWeakMode ? (e is NoSuchMethodError) : (e is TypeError));
+  Expect.throws(
+      () => 9.81 - doubleNull,
+      (e) =>
+          hasUnsoundNullSafety ? (e is NoSuchMethodError) : (e is TypeError));
 
   Expect.throws(() => intNull * 7, (e) => e is NoSuchMethodError);
 }

runtime/tests/vm/dart/transferable_throws_test.dart

@@ -107,7 +107,7 @@ main() async {
   throwsIfCummulativeListIsTooLargeOn32bitPlatform();
 
   dynamic myNull;
-  if (isWeakMode) {
+  if (hasUnsoundNullSafety) {
     Expect.throwsArgumentError(() => TransferableTypedData.fromList(myNull));
     Expect.throwsArgumentError(() => TransferableTypedData.fromList([myNull]));
     Expect.throwsArgumentError(

tests/corelib/reg_exp_all_matches_test.dart

@@ -10,7 +10,7 @@ class RegExpAllMatchesTest {
   static testIterator() {
     var matches = new RegExp("foo").allMatches("foo foo");
     Iterator it = matches.iterator;
-    if (isStrongMode) {
+    if (hasSoundNullSafety) {
       Expect.throws(() => it.current);
     } else {
       Expect.isNull(it.current);

tests/dart2js/internal/rti/required_named_parameters_test.dart

@@ -51,11 +51,13 @@ main() {
 
   // Subtype may not redeclare optional parameters as required
   rti2 = rti.testingUniverseEval(universe, "@(A,{a!A,b!A,c!A})");
-  Expect.equals(isWeakMode, rti.testingIsSubtype(universe, rti2, rti1));
+  Expect.equals(
+      hasUnsoundNullSafety, rti.testingIsSubtype(universe, rti2, rti1));
 
   // Subtype may not declare new required named parameters
   rti2 = rti.testingUniverseEval(universe, "@(A,{a!A,b:A,c!A,d!A})");
-  Expect.equals(isWeakMode, rti.testingIsSubtype(universe, rti2, rti1));
+  Expect.equals(
+      hasUnsoundNullSafety, rti.testingIsSubtype(universe, rti2, rti1));
 
   // Rti.toString() appears as expected
   Expect.equals('(B, {required B a, B b, required B c}) => dynamic',

tests/dart2js/internal/rti/subtype_test.dart

@@ -78,7 +78,7 @@ void testTopTypes() {
 }
 
 void testNull() {
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     unrelated(nullName, 'int');
     unrelated(nullName, 'Iterable<CodeUnits>');
     unrelated(nullName, objectName);
@@ -93,7 +93,7 @@ void testNull() {
 
 void testBottom() {
   String never = '0&';
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     strictSubtype(never, nullName);
   } else {
     equivalent(never, nullName);

tests/dart2js_2/internal/rti/required_named_parameters_test.dart

@@ -51,11 +51,13 @@ main() {
 
   // Subtype may not redeclare optional parameters as required
   rti2 = rti.testingUniverseEval(universe, "@(A,{a!A,b!A,c!A})");
-  Expect.equals(isWeakMode, rti.testingIsSubtype(universe, rti2, rti1));
+  Expect.equals(
+      hasUnsoundNullSafety, rti.testingIsSubtype(universe, rti2, rti1));
 
   // Subtype may not declare new required named parameters
   rti2 = rti.testingUniverseEval(universe, "@(A,{a!A,b:A,c!A,d!A})");
-  Expect.equals(isWeakMode, rti.testingIsSubtype(universe, rti2, rti1));
+  Expect.equals(
+      hasUnsoundNullSafety, rti.testingIsSubtype(universe, rti2, rti1));
 
   // Rti.toString() appears as expected
   Expect.equals('(B, {required B a, B b, required B c}) => dynamic',

tests/language/function_subtype/bound_closure5_test.dart

@@ -39,7 +39,7 @@ main() {
   new D<String, bool>().test('bool', true);
   new D<bool, int>().test('int', false);
   new D<Object, Object>().test('Object', false);
-  new D<Null, Null>().test('Null', isWeakMode);
+  new D<Null, Null>().test('Null', hasUnsoundNullSafety);
   new D<Never, Never>().test('Never', true);
   new D<dynamic, dynamic>().test('dynamic', false);
 }

tests/language/function_subtype/bound_closure5a_test.dart

@@ -41,7 +41,7 @@ main() {
   new D<String, bool>().test('bool', true);
   new D<bool, int>().test('int', false);
   new D<Object, Object>().test('Object', false);
-  new D<Null, Null>().test('Null', isWeakMode);
+  new D<Null, Null>().test('Null', hasUnsoundNullSafety);
   new D<Never, Never>().test('Never', true);
   new D<dynamic, dynamic>().test('dynamic', false);
 }

tests/language/function_subtype/bound_closure6_test.dart

@@ -42,6 +42,6 @@ main() {
   new C<int>().test('int', false);
   new C<Object>().test('Object', false);
   new C<dynamic>().test('dynamic', false);
-  new C<Null>().test('Null', isWeakMode);
+  new C<Null>().test('Null', hasUnsoundNullSafety);
   new C<Never>().test('Never', true);
 }

tests/language/function_subtype/cast2_test.dart

@@ -26,7 +26,7 @@ void bar(int i) {}
 void main() {
   new Class<dynamic>().test(false, bar, "dynamic");
   new Class<Object>().test(false, bar, "Object");
-  new Class<Null>().test(isWeakMode, bar, "Null");
+  new Class<Null>().test(hasUnsoundNullSafety, bar, "Null");
   new Class<Never>().test(true, bar, "Never");
   new Class<int>().test(true, bar, "int");
   new Class<bool>().test(false, bar, "bool");

tests/language/function_subtype/checked0_test.dart

@@ -69,6 +69,6 @@ main() {
   new C<int>().test('int', false);
   new C<dynamic>().test('dynamic', false);
   new C<Object>().test('Object', false);
-  new C<Null>().test('Null', isWeakMode);
+  new C<Null>().test('Null', hasUnsoundNullSafety);
   new C<Never>().test('Null', true);
 }

tests/language/function_subtype/inline0_test.dart

@@ -41,7 +41,7 @@ class C<T> {
 }
 
 main() {
-  new C<bool>().test('bool', true, isWeakMode);
+  new C<bool>().test('bool', true, hasUnsoundNullSafety);
   new C<int>().test('int', false, false);
-  new C<dynamic>().test('dynamic', true, isWeakMode);
+  new C<dynamic>().test('dynamic', true, hasUnsoundNullSafety);
 }

tests/language/function_subtype/inline2_test.dart

@@ -23,7 +23,7 @@ void test(var f, String constructorName) {
   testDynamicTypeError(false, () => f(m1), "'new C.$constructorName(m1)'");
   testDynamicTypeError(true, () => f(m2), "'new C.$constructorName(m2)'");
   testDynamicTypeError(
-      isStrongMode, () => f(m3), "'new C.$constructorName(m3)'");
+      hasSoundNullSafety, () => f(m3), "'new C.$constructorName(m3)'");
   testDynamicTypeError(true, () => f(m4), "'new C.$constructorName(m4)'");
   testDynamicTypeError(false, () => f(m5), "'new C.$constructorName(m5)'");
 }

tests/language/function_subtype/local2_test.dart

@@ -38,6 +38,6 @@ main() {
   new C<int>().test('int', false);
   new C<dynamic>().test('dynamic', false);
   new C<Object>().test('Object', false);
-  new C<Null>().test('Null', isWeakMode);
+  new C<Null>().test('Null', hasUnsoundNullSafety);
   new C<Never>().test('Never', true);
 }

tests/language/function_subtype/local5_test.dart

@@ -40,6 +40,6 @@ main() {
   new D<bool, int>().test('int', false);
   new D<dynamic, dynamic>().test('dynamic', false);
   new D<Object, Object>().test('Object', false);
-  new D<Null, Null>().test('Null', isWeakMode);
+  new D<Null, Null>().test('Null', hasUnsoundNullSafety);
   new D<Never, Never>().test('Never', true);
 }

tests/language/function_subtype/not2_test.dart

@@ -22,7 +22,7 @@ void bar(int i) {}
 void main() {
   new Class<dynamic>().test(true, bar, "dynamic");
   new Class<Object>().test(true, bar, "Object");
-  new Class<Null>().test(isStrongMode, bar, "Null");
+  new Class<Null>().test(hasSoundNullSafety, bar, "Null");
   new Class<Never>().test(false, bar, "Never");
   new Class<int>().test(false, bar, "int");
   new Class<bool>().test(true, bar, "bool");

tests/language/function_subtype/not3_test.dart

@@ -26,7 +26,7 @@ void bar(int i) {}
 void main() {
   new Class<dynamic>().test(true, bar, "dynamic");
   new Class<Object>().test(true, bar, "Object");
-  new Class<Null>().test(isStrongMode, bar, "Null");
+  new Class<Null>().test(hasSoundNullSafety, bar, "Null");
   new Class<Never>().test(false, bar, "Never");
   new Class<int>().test(false, bar, "int");
   new Class<bool>().test(true, bar, "bool");

tests/language/function_subtype/top_level1_test.dart

@@ -40,6 +40,6 @@ main() {
   new C<int>().test('int', false);
   new C<Object>().test('Object', false);
   new C<dynamic>().test('dynamic', false);
-  new C<Null>().test('Null', isWeakMode);
+  new C<Null>().test('Null', hasUnsoundNullSafety);
   new C<Never>().test('Never', true);
 }

tests/language/generic/instanceof.dart

@@ -56,7 +56,7 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<List<Object>>();
-      Expect.equals(isWeakMode, foo.isT(new List.filled(5, null)));
+      Expect.equals(hasUnsoundNullSafety, foo.isT(new List.filled(5, null)));
       Expect.equals(true, foo.isT(new List<Object>.filled(5, "o")));
       Expect.equals(true, foo.isT(new List<int>.filled(5, 0)));
       Expect.equals(true, foo.isT(new List<num>.filled(5, 0)));
@@ -64,7 +64,7 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<List<int>>();
-      Expect.equals(isWeakMode, foo.isT(new List.filled(5, null)));
+      Expect.equals(hasUnsoundNullSafety, foo.isT(new List.filled(5, null)));
       Expect.equals(false, foo.isT(new List<Object>.filled(5, "o")));
       Expect.equals(true, foo.isT(new List<int>.filled(5, 0)));
       Expect.equals(false, foo.isT(new List<num>.filled(5, 0)));
@@ -72,7 +72,7 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<List<num>>();
-      Expect.equals(isWeakMode, foo.isT(new List.filled(5, null)));
+      Expect.equals(hasUnsoundNullSafety, foo.isT(new List.filled(5, null)));
       Expect.equals(false, foo.isT(new List<Object>.filled(5, "o")));
       Expect.equals(true, foo.isT(new List<int>.filled(5, 0)));
       Expect.equals(true, foo.isT(new List<num>.filled(5, 0)));
@@ -80,7 +80,7 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<List<String>>();
-      Expect.equals(isWeakMode, foo.isT(new List.filled(5, null)));
+      Expect.equals(hasUnsoundNullSafety, foo.isT(new List.filled(5, null)));
       Expect.equals(false, foo.isT(new List<Object>.filled(5, "o")));
       Expect.equals(false, foo.isT(new List<int>.filled(5, 0)));
       Expect.equals(false, foo.isT(new List<num>.filled(5, 0)));
@@ -96,7 +96,8 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<Object>();
-      Expect.equals(isWeakMode, foo.isListT(new List.filled(5, null)));
+      Expect.equals(
+          hasUnsoundNullSafety, foo.isListT(new List.filled(5, null)));
       Expect.equals(true, foo.isListT(new List<Object>.filled(5, "o")));
       Expect.equals(true, foo.isListT(new List<int>.filled(5, 0)));
       Expect.equals(true, foo.isListT(new List<num>.filled(5, 0)));
@@ -104,7 +105,8 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<int>();
-      Expect.equals(isWeakMode, foo.isListT(new List.filled(5, null)));
+      Expect.equals(
+          hasUnsoundNullSafety, foo.isListT(new List.filled(5, null)));
       Expect.equals(false, foo.isListT(new List<Object>.filled(5, "o")));
       Expect.equals(true, foo.isListT(new List<int>.filled(5, 0)));
       Expect.equals(false, foo.isListT(new List<num>.filled(5, 0)));
@@ -112,7 +114,8 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<num>();
-      Expect.equals(isWeakMode, foo.isListT(new List.filled(5, null)));
+      Expect.equals(
+          hasUnsoundNullSafety, foo.isListT(new List.filled(5, null)));
       Expect.equals(false, foo.isListT(new List<Object>.filled(5, "o")));
       Expect.equals(true, foo.isListT(new List<int>.filled(5, 0)));
       Expect.equals(true, foo.isListT(new List<num>.filled(5, 0)));
@@ -120,7 +123,8 @@ class GenericInstanceof {
     }
     {
       Foo foo = new Foo<String>();
-      Expect.equals(isWeakMode, foo.isListT(new List.filled(5, null)));
+      Expect.equals(
+          hasUnsoundNullSafety, foo.isListT(new List.filled(5, null)));
       Expect.equals(false, foo.isListT(new List<Object>.filled(5, "o")));
       Expect.equals(false, foo.isListT(new List<int>.filled(5, 0)));
       Expect.equals(false, foo.isListT(new List<num>.filled(5, 0)));

tests/language/generic_methods/generic_class_tearoff_test.dart

@@ -38,6 +38,6 @@ main() {
 
   Expect.isTrue(h is! Int2Int);
   Expect.isTrue(h is! String2String);
-  Expect.equals(isWeakMode, h is Object2Object);
+  Expect.equals(hasUnsoundNullSafety, h is Object2Object);
   Expect.isTrue(h is! GenericMethod);
 }

tests/language/is/is2_test.dart

@@ -59,7 +59,7 @@ class InstanceofTest {
       var a = new List.empty();
       Expect.equals(true, a is List);
       Expect.equals(true, a is List<Object?>);
-      Expect.equals(isWeakMode, a is List<Object>);
+      Expect.equals(hasUnsoundNullSafety, a is List<Object>);
       Expect.equals(false, a is List<int>);
       Expect.equals(false, a is List<num>);
       Expect.equals(false, a is List<String>);

tests/language/nnbd/constant_null_safety_mode_test.dart

@@ -5,15 +5,15 @@
 import 'package:expect/expect.dart';
 
 main() {
-  const trueInWeakMode = <Null>[] is List<int>;
-  Expect.equals(isWeakMode, trueInWeakMode);
+  const trueInNoSoundMode = <Null>[] is List<int>;
+  Expect.equals(hasUnsoundNullSafety, trueInNoSoundMode);
 
   // The following tests use the Uri.pathSegments() to access a constant list
   // that is defined in the SDK and verify the type associated with it does not
   // allow null when running with sound null safety.
   var emptyUri = Uri(pathSegments: []);
   dynamic stringList = emptyUri.pathSegments.toList();
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(() {
       stringList.add(null);
     });

tests/language/null/null_test.dart

@@ -145,13 +145,13 @@ void test() {
 
   // Test cast, "as", operator.
   Expect.equals(null, null as Null);
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(() => null as Object);
   } else {
     Expect.equals(null, null as Object);
   }
   Expect.equals(null, null as Object?);
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(() => null as int);
   } else {
     Expect.equals(null, null as int);
@@ -163,13 +163,13 @@ void test() {
   Expect.equals(null, new Generic<int?>().cast(null));
 
   Expect.equals(null, obj as Null);
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(() => obj as Object);
   } else {
     Expect.equals(null, obj as Object);
   }
   Expect.equals(null, obj as Object?);
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(() => obj as int);
   } else {
     Expect.equals(null, obj as int);

tests/language/regress/regress34147_test.dart

@@ -16,7 +16,7 @@ void main() {
 }
 
 void expectError(Function() callback) {
-  if (isWeakMode) {
+  if (hasUnsoundNullSafety) {
     Expect.throwsAssertionError(callback);
   } else {
     Expect.throwsTypeError(callback);

tests/language/regress/regress41890_test.dart

@@ -43,8 +43,8 @@ void test() {
       var item = items[i];
       String code = answers[i];
       bool expected = code == 'T' ||
-          (code == 'S' && isStrongMode) ||
-          (code == 'W' && isWeakMode);
+          (code == 'S' && hasSoundNullSafety) ||
+          (code == 'W' && hasUnsoundNullSafety);
       Expect.equals(expected, predicate(item), "$predicate '$code' $item");
     }
   }

tests/language/vm/bool_check_stack_traces_test.dart

@@ -81,7 +81,7 @@ void testStackTrace(void testCase(dynamic condition), List<int> lineNumbers) {
     print(stacktrace);
     print('-----------------------------');
 
-    if (isStrongMode) {
+    if (hasSoundNullSafety) {
       Expect.isTrue(e is TypeError);
       Expect.equals(
           "type 'Null' is not a subtype of type 'bool'", e.toString());

tests/lib/mirrors/null_test.dart

@@ -18,7 +18,7 @@ void test() {
 
   InstanceMirror im1 = reflect(null);
   Expect.equals(cm, im1.type);
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(() => im1.invoke(const Symbol("=="), [null]),
         'null not assignable to Object');
   } else {
@@ -29,7 +29,7 @@ void test() {
   var obj = confuse(null); // Null value that isn't known at compile-time.
   InstanceMirror im2 = reflect(obj);
   Expect.equals(cm, im2.type);
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(() => im2.invoke(const Symbol("=="), [null]),
         'null not assignable to Object');
   } else {
@@ -41,7 +41,7 @@ void test() {
   Expect.isTrue(nullMirror.getField(#hashCode).reflectee is int);
   Expect.equals(null.hashCode, nullMirror.getField(#hashCode).reflectee);
   Expect.equals('Null', nullMirror.getField(#runtimeType).reflectee.toString());
-  if (isStrongMode) {
+  if (hasSoundNullSafety) {
     Expect.throwsTypeError(
         () => nullMirror.invoke(#==, [null]), 'null not assignable to Object');
   } else {