Class fields, part 3 (backends)

test/mjsunit/harmony/class-fields-syntax.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-class-fields
+
+// ASI
+
+{
+  class C {
+    a = 0
+    b(){}
+  }
+
+  let c = new C;
+  assertArrayEquals(['constructor', 'b'], Object.getOwnPropertyNames(C.prototype));
+  assertArrayEquals(['a'], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C {
+    a
+    b(){}
+  }
+
+  let c = new C;
+  assertArrayEquals(['constructor', 'b'], Object.getOwnPropertyNames(C.prototype));
+  assertArrayEquals(['a'], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C {
+    a
+    b
+  }
+
+  let c = new C;
+  assertArrayEquals(['constructor'], Object.getOwnPropertyNames(C.prototype));
+  assertArrayEquals(['a', 'b'], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C {
+    a
+    *b(){}
+  }
+
+  let c = new C;
+  assertArrayEquals(['constructor', 'b'], Object.getOwnPropertyNames(C.prototype));
+  assertArrayEquals(['a'], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C {
+    a
+    ['b'](){}
+  }
+
+  let c = new C;
+  assertArrayEquals(['constructor', 'b'], Object.getOwnPropertyNames(C.prototype));
+  assertArrayEquals(['a'], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C { // a property named 'a' and a property named 'get'
+    a
+    get
+  }
+
+  let c = new C;
+  assertArrayEquals(['constructor'], Object.getOwnPropertyNames(C.prototype));
+  assertArrayEquals(['a', 'get'], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C {
+    get
+    *a(){}
+  }
+
+  let c = new C;
+  assertArrayEquals(['constructor', 'a'], Object.getOwnPropertyNames(C.prototype));
+  assertArrayEquals(['get'], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C { // a single static property named 'a'
+    static
+    a
+  }
+
+  let c = new C;
+  //assertArrayEquals(['length', 'name', 'prototype', 'a'], Object.getOwnPropertyNames(C)); // TODO(bakkot) re-enable once no longer using fields to communicate
+  assertArrayEquals([], Object.getOwnPropertyNames(c));
+}
+
+{
+  class C { // a property named 'a' and a property named 'static'
+    a
+    static
+  }
+
+  let c = new C;
+  //assertArrayEquals(['length', 'name', 'prototype'], Object.getOwnPropertyNames(C)); // TODO(bakkot) re-enable once no longer using fields to communicate
+  assertArrayEquals(['a', 'static'], Object.getOwnPropertyNames(c));
+}
+
+
+// ASI non-examples / errors
+
+assertThrows(() => eval(`
+  class C { a b }
+`)); // There is no line terminator after 'a', so ASI does not occur
+
+assertThrows(() => eval(`
+  class C {
+    a = 0
+    *b(){}
+  }
+`)); // '*' may follow 0 in an AssignmentExpression, so no ASI occurs after 0
+
+assertThrows(() => eval(`
+  class C {
+    a = 0
+    ['b'](){}
+  }
+`)); // '[' may follow 0 in an AssignmentExpression, so no ASI occurs after 0
+
+assertThrows(() => eval(`
+  class C {
+    get
+    a
+  }
+`)); // 'a' may follow 'get' in a MethodDefinition, so no ASI occurs after 'get'
+
+
+// Forbid static properties named 'prototype'
+
+// assertThrows(() => eval(`
+//   class C {
+//     static prototype;
+//   }
+// `), SyntaxError); // TODO(bakkot) re-enable once this restriction is spec'd and added
+
+// assertThrows(() => eval(`
+//   class C {
+//     static prototype;
+//   }
+// `), TypeError); // TODO(bakkot) re-enable once this restriction is spec'd and added
+
+
+// Non-examples
+
+{
+  class C { // a getter for 'a' on C.prototype; this is pre-existing syntax
+    get
+    a(){}
+  }
+
+  let c = new C;
+  assertTrue(Object.getOwnPropertyDescriptor(C.prototype, 'a').hasOwnProperty('get'));
+  assertArrayEquals([], Object.getOwnPropertyNames(c));
+}