[ddc] Fix is type tests on nullable types

Types that are represented by primitives in JS were dropping the
nullable portion when used in `is` type tests.

Add regression test expectations for all built in dart types and
a version of the tests that can run with sound null safety.

Change-Id: I155a673ac23132eb06749d890bce272db3248b33
Fixes: #42851
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/156060
Reviewed-by: Mark Zhou <[email protected]>
Commit-Queue: Nicholas Shahan <[email protected]>

Author: nshahan

pkg/dev_compiler/lib/src/kernel/compiler.dart

@@ -5300,11 +5300,11 @@ class ProgramCompiler extends ComputeOnceConstantVisitor<js_ast.Expression>
     // Generate `is` as `dart.is` or `typeof` depending on the RHS type.
     var lhs = _visitExpression(operand);
     var typeofName = _typeRep.typeFor(type).primitiveTypeOf;
-    // Inline primitives other than int (which requires a Math.floor check).
+    // Inline non-nullable primitive types other than int (which requires a
+    // Math.floor check).
     if (typeofName != null &&
-        type != _types.coreTypes.intLegacyRawType &&
-        type != _types.coreTypes.intNonNullableRawType &&
-        type != _types.coreTypes.intNullableRawType) {
+        type.nullability == Nullability.nonNullable &&
+        type != _types.coreTypes.intNonNullableRawType) {
       return js.call('typeof # == #', [lhs, js.string(typeofName, "'")]);
     } else {
       return js.call('#.is(#)', [_emitType(type), lhs]);

tests/language/nnbd/is_type_test/null_is_test.dart

@@ -0,0 +1,36 @@
+// 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.
+
+import 'package:expect/expect.dart';
+
+// Type tests (is checks) located in a null safe library.
+main() {
+  Expect.isFalse(null is Never);
+  Expect.isTrue(null is Never?);
+  Expect.isTrue(null is Null);
+  Expect.isFalse(null is Object);
+  Expect.isTrue(null is Object?);
+  Expect.isTrue(null is dynamic);
+
+  // Testing all built in types because of a regression that caused them to be
+  // handled differently https://github.com/dart-lang/sdk/issues/42851.
+  Expect.isFalse(null is bool);
+  Expect.isTrue(null is bool?);
+  Expect.isFalse(null is num);
+  Expect.isTrue(null is num?);
+  Expect.isFalse(null is int);
+  Expect.isTrue(null is int?);
+  Expect.isFalse(null is double);
+  Expect.isTrue(null is double?);
+  Expect.isFalse(null is String);
+  Expect.isTrue(null is String?);
+  Expect.isFalse(null is List);
+  Expect.isTrue(null is List?);
+  Expect.isFalse(null is Set);
+  Expect.isTrue(null is Set?);
+  Expect.isFalse(null is Map);
+  Expect.isTrue(null is Map?);
+  Expect.isFalse(null is Symbol);
+  Expect.isTrue(null is Symbol?);
+}

tests/language/nnbd/is_type_test/null_is_type_in_legacy_lib_test.dart

@@ -18,13 +18,48 @@ main() {
   // `null is Never?`
   Expect.isTrue(legacyIsNullable<Never>(null));
   Expect.isTrue(null is Null);
-  // `null is int*`
-  Expect.isFalse(null is int);
-  // `null is int?`
-  Expect.isTrue(legacyIsNullable<int>(null));
   // `null is Object*`
   Expect.isTrue(null is Object);
   // `null is Object?`
   Expect.isTrue(legacyIsNullable<Object>(null));
   Expect.isTrue(null is dynamic);
+
+  // Testing all built in types because of a regression that caused them to be
+  // handled differently https://github.com/dart-lang/sdk/issues/42851.
+  // `null is bool*`
+  Expect.isFalse(null is bool);
+  // `null is bool?`
+  Expect.isTrue(legacyIsNullable<bool>(null));
+  // `null is num*`
+  Expect.isFalse(null is num);
+  // `null is num?`
+  Expect.isTrue(legacyIsNullable<num>(null));
+  // `null is int*`
+  Expect.isFalse(null is int);
+  // `null is int?`
+  Expect.isTrue(legacyIsNullable<int>(null));
+  // `null is double*`
+  Expect.isFalse(null is double);
+  // `null is double?`
+  Expect.isTrue(legacyIsNullable<double>(null));
+  // `null is String*`
+  Expect.isFalse(null is String);
+  // `null is String?`
+  Expect.isTrue(legacyIsNullable<String>(null));
+  // `null is List*`
+  Expect.isFalse(null is List);
+  // `null is List?
+  Expect.isTrue(legacyIsNullable<List>(null));
+  // `null is Set*`
+  Expect.isFalse(null is Set);
+  // `null is Set?
+  Expect.isTrue(legacyIsNullable<Set>(null));
+  // `null is Map*`
+  Expect.isFalse(null is Map);
+  // `null is Map?
+  Expect.isTrue(legacyIsNullable<Map>(null));
+  // `null is Symbol*`
+  Expect.isFalse(null is Symbol);
+  // `null is Symbol?
+  Expect.isTrue(legacyIsNullable<Symbol>(null));
 }

tests/language/nnbd/is_type_test/null_is_type_in_null_safe_lib_test.dart

@@ -15,13 +15,48 @@ main() {
   Expect.isTrue(nullSafeIsLegacy<Never>(null));
   Expect.isTrue(null is Never?);
   Expect.isTrue(null is Null);
-  Expect.isFalse(null is int);
-  // `null is int*`
-  Expect.isFalse(nullSafeIsLegacy<int>(null));
-  Expect.isTrue(null is int?);
   Expect.isFalse(null is Object);
   // `null is Object*`
   Expect.isTrue(nullSafeIsLegacy<Object>(null));
   Expect.isTrue(null is Object?);
   Expect.isTrue(null is dynamic);
+
+  // Testing all built in types because of a regression that caused them to be
+  // handled differently https://github.com/dart-lang/sdk/issues/42851.
+  Expect.isFalse(null is bool);
+  // `null is bool*`
+  Expect.isFalse(nullSafeIsLegacy<bool>(null));
+  Expect.isTrue(null is bool?);
+  Expect.isFalse(null is num);
+  // `null is num*`
+  Expect.isFalse(nullSafeIsLegacy<num>(null));
+  Expect.isTrue(null is num?);
+  Expect.isFalse(null is int);
+  // `null is int*`
+  Expect.isFalse(nullSafeIsLegacy<int>(null));
+  Expect.isTrue(null is int?);
+  Expect.isFalse(null is double);
+  // `null is double*`
+  Expect.isFalse(nullSafeIsLegacy<double>(null));
+  Expect.isTrue(null is double?);
+  Expect.isFalse(null is String);
+  // `null is String*`
+  Expect.isFalse(nullSafeIsLegacy<String>(null));
+  Expect.isTrue(null is String?);
+  Expect.isFalse(null is List);
+  // `null is List*`
+  Expect.isFalse(nullSafeIsLegacy<List>(null));
+  Expect.isTrue(null is List?);
+  Expect.isFalse(null is Set);
+  // `null is Set*`
+  Expect.isFalse(nullSafeIsLegacy<Set>(null));
+  Expect.isTrue(null is Set?);
+  Expect.isFalse(null is Map);
+  // `null is Map*`
+  Expect.isFalse(nullSafeIsLegacy<Map>(null));
+  Expect.isTrue(null is Map?);
+  Expect.isFalse(null is Symbol);
+  // `null is Symbol*`
+  Expect.isFalse(nullSafeIsLegacy<Symbol>(null));
+  Expect.isTrue(null is Symbol?);
 }