Add additional definitions to JSSymbol

CHANGELOG.md

@@ -16,6 +16,12 @@
  but `false` on Windows. Use `FileSystemEntity.typeSync()` instead to get
  portable behavior.
 
+#### `dart:js_interop`
+
+- Added a constructor to `JSSymbol`, as well as `JSSymbol.key`,
+ `JSSymbol.description`, and static methods for all well-known ECMAScript
+ symbols.
+
 #### `dart:js_util`
 
 - dart2wasm no longer supports `dart:js_util`. Any code that imports

sdk/lib/js_interop/js_interop.dart

@@ -529,8 +529,137 @@ extension type JSBoolean._(JSBooleanRepType _jsBoolean) implements JSAny {}
 /// A JavaScript string.
 extension type JSString._(JSStringRepType _jsString) implements JSAny {}
 
+@JS('Symbol')
+external JSSymbol _constructSymbol([String? description]);
+
 /// A JavaScript `Symbol`.
-extension type JSSymbol._(JSSymbolRepType _jsSymbol) implements JSAny {}
+extension type JSSymbol._(JSSymbolRepType _jsSymbol) implements JSAny {
+ // TODO(srujzs): See if this can be made `const` so it can be used in similar
+ // situations to a Dart symbol literal.
+ /// Creates a new, unique JavaScript `Symbol`.
+ ///
+ /// If [description] is provided, it's used for debugging but not to access
+ /// the symbol itself.
+ @Since('3.11')
+ JSSymbol([String? description]) =>
+ description == null ? _constructSymbol() : _constructSymbol(description);
+
+ /// Aearches for an existing symbol in a runtime-wide symbol registry with the
+ /// given key and returns it if found.
+ ///
+ /// Otherwise, creates a new symbol with this key, adds it to the global
+ /// registry, and returns it.
+ @Since('3.11')
+ @JS('for')
+ external static JSSymbol forKey(String key);
+
+ /// `Symbol.asyncDispose` from the ECMAScript [explicit resource management]
+ /// feature.
+ ///
+ /// [explicit resource management]: https://github.com/tc39/proposal-explicit-resource-management
+ @Since('3.11')
+ external static JSSymbol get asyncDispose;
+
+ /// See [`Symbol.asyncIterator`].
+ ///
+ /// [`Symbol.asyncIterator`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/asyncIterator
+ @Since('3.11')
+ external static JSSymbol get asyncIterator;
+
+ /// `Symbol.dispose` from the ECMAScript [explicit resource management]
+ /// feature.
+ ///
+ /// [explicit resource management]: https://github.com/tc39/proposal-explicit-resource-management
+ @Since('3.11')
+ external static JSSymbol get dispose;
+
+ /// See [`Symbol.hasInstance`].
+ ///
+ /// [`Symbol.hasInstance`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/hasInstance
+ @Since('3.11')
+ external static JSSymbol get hasInstance;
+
+ /// See [`Symbol.isConcatSpreadable`].
+ ///
+ /// [`Symbol.isConcatSpreadable`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/isConcatSpreadable
+ @Since('3.11')
+ external static JSSymbol get isConcatSpreadable;
+
+ /// See [`Symbol.iterator`].
+ ///
+ /// [`Symbol.iterator`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/iterator
+ @Since('3.11')
+ external static JSSymbol get iterator;
+
+ /// See [`Symbol.match`].
+ ///
+ /// [`Symbol.match`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/match
+ @Since('3.11')
+ external static JSSymbol get match;
+
+ /// See [`Symbol.matchAll`].
+ ///
+ /// [`Symbol.matchAll`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/matchAll
+ @Since('3.11')
+ external static JSSymbol get matchAll;
+
+ /// See [`Symbol.replace`].
+ ///
+ /// [`Symbol.replace`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/replace
+ @Since('3.11')
+ external static JSSymbol get replace;
+
+ /// See [`Symbol.search`].
+ ///
+ /// [`Symbol.search`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/search
+ @Since('3.11')
+ external static JSSymbol get search;
+
+ /// See [`Symbol.species`].
+ ///
+ /// [`Symbol.species`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/species
+ @Since('3.11')
+ external static JSSymbol get species;
+
+ /// See [`Symbol.split`].
+ ///
+ /// [`Symbol.split`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/split
+ @Since('3.11')
+ external static JSSymbol get split;
+
+ /// See [`Symbol.toPrimitive`].
+ ///
+ /// [`Symbol.toPrimitive`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toPrimitive
+ @Since('3.11')
+ external static JSSymbol get toPrimitive;
+
+ /// See [`Symbol.toStringTag`].
+ ///
+ /// [`Symbol.toStringTag`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toStringTag
+ @Since('3.11')
+ external static JSSymbol get toStringTag;
+
+ /// See [`Symbol.unscopables`].
+ ///
+ /// [`Symbol.unscopables`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/unscopables
+ @Since('3.11')
+ external static JSSymbol get unscopables;
+
+ @Since('3.11')
+ @JS('keyFor')
+ external static String? _keyFor(JSSymbol symbol);
+
+ /// Returns the shared symbol key from the global symbol registry for this
+ /// symbol (as registered with [forKey]), if this symbol was created with
+ /// [Symbol.forKey].
+ @Since('3.11')
+ String get key => _keyFor(this);
+
+ /// A string containing the description of the symbol, as passed to [new
+ /// Symbol].
+ @Since('3.11')
+ external String get description;
+}
 
 /// A JavaScript `BigInt`.
 extension type JSBigInt._(JSBigIntRepType _jsBigInt) implements JSAny {}