[dartdevc] Update is, as, and _check methods for null safety

Change-Id: I67e97c988a0c7a0e9d04e84e85c07152f8f35306 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/129202 Reviewed-by: Sigmund Cherem <sigmund@google.com> Commit-Queue: Nicholas Shahan <nshahan@google.com>
flutter · Jan 2, 2020 · 2f57602 · 2f57602
1 parent 3aa23f8
commit 2f57602
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Showing 4 changed files with 46 additions and 20 deletions.
diff --git a/sdk_nnbd/lib/_internal/js_dev_runtime/patch/core_patch.dart b/sdk_nnbd/lib/_internal/js_dev_runtime/patch/core_patch.dart
@@ -66,13 +66,15 @@ class Object {
 
   // Everything is an Object.
   @JSExportName('is')
-  static bool _is_Object(Object o) => true;
+  static bool _is_Object(Object o) => o != null;
 
   @JSExportName('as')
-  static Object _as_Object(Object o) => o;
+  static Object _as_Object(Object o) =>
+      o == null ? dart.cast(o, dart.unwrapType(Object), false) : o;
 
   @JSExportName('_check')
-  static Object _check_Object(Object o) => o;
+  static Object _check_Object(Object o) =>
+      o == null ? dart.cast(o, dart.unwrapType(Object), true) : o;
 }
 
 @patch
@@ -132,14 +134,14 @@ class Function {
   @JSExportName('as')
   static Object _as_Function(Object o) {
     // Avoid extra function call to core.Function.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "function"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "function"')) return o;
     return dart.cast(o, dart.unwrapType(Function), false);
   }
 
   @JSExportName('_check')
   static Object _check_Function(Object o) {
     // Avoid extra function call to core.Function.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "function"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "function"')) return o;
     return dart.cast(o, dart.unwrapType(Function), true);
   }
 }
@@ -211,8 +213,7 @@ class int {
   @JSExportName('as')
   static Object _as_int(Object o) {
     // Avoid extra function call to core.int.is() by manually inlining.
-    if (JS<bool>('!', '(typeof $o == "number" && Math.floor($o) == $o)') ||
-        o == null) {
+    if (JS<bool>('!', '(typeof $o == "number" && Math.floor($o) == $o)')) {
       return o;
     }
     return dart.cast(o, dart.unwrapType(int), false);
@@ -221,8 +222,7 @@ class int {
   @JSExportName('_check')
   static Object _check_int(Object o) {
     // Avoid extra function call to core.int.is() by manually inlining.
-    if (JS<bool>('!', '(typeof $o == "number" && Math.floor($o) == $o)') ||
-        o == null) {
+    if (JS<bool>('!', '(typeof $o == "number" && Math.floor($o) == $o)')) {
       return o;
     }
     return dart.cast(o, dart.unwrapType(int), true);
@@ -250,14 +250,14 @@ class double {
   @JSExportName('as')
   static Object _as_double(o) {
     // Avoid extra function call to core.double.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "number"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "number"')) return o;
     return dart.cast(o, dart.unwrapType(double), false);
   }
 
   @JSExportName('_check')
   static Object _check_double(o) {
     // Avoid extra function call to core.double.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "number"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "number"')) return o;
     return dart.cast(o, dart.unwrapType(double), true);
   }
 }
@@ -272,14 +272,14 @@ abstract class num implements Comparable<num> {
   @JSExportName('as')
   static Object _as_num(o) {
     // Avoid extra function call to core.num.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "number"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "number"')) return o;
     return dart.cast(o, dart.unwrapType(num), false);
   }
 
   @JSExportName('_check')
   static Object _check_num(o) {
     // Avoid extra function call to core.num.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "number"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "number"')) return o;
     return dart.cast(o, dart.unwrapType(num), true);
   }
 }
@@ -652,14 +652,14 @@ class String {
   @JSExportName('as')
   static Object _as_String(Object o) {
     // Avoid extra function call to core.String.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "string"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "string"')) return o;
     return dart.cast(o, dart.unwrapType(String), false);
   }
 
   @JSExportName('_check')
   static Object _check_String(Object o) {
     // Avoid extra function call to core.String.is() by manually inlining.
-    if (JS<bool>('!', 'typeof $o == "string"') || o == null) return o;
+    if (JS<bool>('!', 'typeof $o == "string"')) return o;
     return dart.cast(o, dart.unwrapType(String), true);
   }
 }
@@ -683,14 +683,14 @@ class bool {
   @JSExportName('as')
   static Object _as_bool(Object o) {
     // Avoid extra function call to core.bool.is() by manually inlining.
-    if (JS<bool>("!", '$o === true || $o === false') || o == null) return o;
+    if (JS<bool>("!", '$o === true || $o === false')) return o;
     return dart.cast(o, dart.unwrapType(bool), false);
   }
 
   @JSExportName('_check')
   static Object _check_bool(Object o) {
     // Avoid extra function call to core.bool.is() by manually inlining.
-    if (JS<bool>("!", '$o === true || $o === false') || o == null) return o;
+    if (JS<bool>("!", '$o === true || $o === false')) return o;
     return dart.cast(o, dart.unwrapType(bool), true);
   }
 }

diff --git a/sdk_nnbd/lib/_internal/js_dev_runtime/private/ddc_runtime/classes.dart b/sdk_nnbd/lib/_internal/js_dev_runtime/private/ddc_runtime/classes.dart
@@ -508,7 +508,7 @@ addTypeTests(ctor, isClass) {
   JS(
       '',
       '''#.as = function as_C(obj) {
-    if (obj == null || obj[#]) return obj;
+    if (obj != null && obj[#]) return obj;
     return #(obj, this, false);
   }''',
       ctor,
@@ -517,7 +517,7 @@ addTypeTests(ctor, isClass) {
   JS(
       '',
       '''#._check = function check_C(obj) {
-    if (obj == null || obj[#]) return obj;
+    if (obj != null && obj[#]) return obj;
     return #(obj, this, true);
   }''',
       ctor,

diff --git a/sdk_nnbd/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart b/sdk_nnbd/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart
@@ -428,7 +428,7 @@ bool instanceOf(obj, type) {
 
 @JSExportName('as')
 cast(obj, type, @notNull bool isImplicit) {
-  if (obj == null) return obj;
+  if (obj == null && (_isNullable(type) || _isNullType(type))) return obj;
   var actual = getReifiedType(obj);
   if (isSubtypeOf(actual, type)) {
     return obj;

diff --git a/sdk_nnbd/lib/_internal/js_dev_runtime/private/ddc_runtime/types.dart b/sdk_nnbd/lib/_internal/js_dev_runtime/private/ddc_runtime/types.dart
@@ -292,6 +292,19 @@ class NullableType extends DartType {
 
   @override
   String toString() => name;
+
+  @JSExportName('is')
+  bool is_T(obj) => obj == null || JS<bool>('!', '#.is(#)', type, obj);
+
+  @JSExportName('as')
+  as_T(obj) => obj == null || JS<bool>('!', '#.is(#)', type, obj)
+      ? obj
+      : cast(obj, this, false);
+
+  @JSExportName('_check')
+  check_T(obj) => obj == null || JS<bool>('!', '#.is(#)', type, obj)
+      ? obj
+      : cast(obj, this, true);
 }
 
 /// A wrapper to identify a legacy (star, *) type of the form [type]*.
@@ -307,6 +320,19 @@ class LegacyType extends DartType {
 
   @override
   String toString() => name;
+
+  @JSExportName('is')
+  bool is_T(obj) => obj != null && JS<bool>('!', '#.is(#)', type, obj);
+
+  @JSExportName('as')
+  as_T(obj) => obj == null || JS<bool>('!', '#.is(#)', type, obj)
+      ? obj
+      : cast(obj, this, false);
+
+  @JSExportName('_check')
+  check_T(obj) => obj == null || JS<bool>('!', '#.is(#)', type, obj)
+      ? obj
+      : cast(obj, this, true);
 }
 
 // TODO(nshahan) Add override optimizations for is, as and _check?