Support ES6's "new function" construct

This resolves #75.

Merged remote-tracking branch 'janek/js_function_new_1'

3 files changed, 139 insertions, 0 deletions

diff --git a/js/src/tests/ecma_6/Function/invalid-parameter-list.js b/js/src/tests/ecma_6/Function/invalid-parameter-list.js
new file mode 100644
index 000000000..8aae89ef1
--- /dev/null
+++ b/js/src/tests/ecma_6/Function/invalid-parameter-list.js
@@ -0,0 +1,27 @@
+// This constructor behaves like `Function` without checking
+// if the parameter list end is at the expected position.
+// We use this to make sure that the tests we use are otherwise
+// syntactically correct.
+function DumpFunction(...args) {
+    let code = "function anonymous(";
+    code += args.slice(0, -1).join(", ");
+    code += ") {\n";
+    code += args[args.length -1];
+    code += "\n}";
+    eval(code);
+}
+
+const tests = [
+    ["/*", "*/) {"],
+    ["//", ") {"],
+    ["a = `", "` ) {"],
+    [") { var x = function (", "} "],
+    ["x = function (", "}) {"]
+];
+
+for (const test of tests) {
+    DumpFunction(...test);
+    assertThrowsInstanceOf(() => new Function(...test), SyntaxError);
+}
+
+reportCompare(0, 0, 'ok');
diff --git a/js/src/tests/ecma_6/Generators/construct-newtarget.js b/js/src/tests/ecma_6/Generators/construct-newtarget.js
new file mode 100644
index 000000000..f2087852b
--- /dev/null
+++ b/js/src/tests/ecma_6/Generators/construct-newtarget.js
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const GeneratorFunction = function*(){}.constructor;
+
+
+// Test subclassing %GeneratorFunction% works correctly.
+class MyGenerator extends GeneratorFunction {}
+
+var fn = new MyGenerator();
+assertEq(fn instanceof MyGenerator, true);
+assertEq(fn instanceof GeneratorFunction, true);
+assertEq(Object.getPrototypeOf(fn), MyGenerator.prototype);
+
+fn = Reflect.construct(MyGenerator, []);
+assertEq(fn instanceof MyGenerator, true);
+assertEq(fn instanceof GeneratorFunction, true);
+assertEq(Object.getPrototypeOf(fn), MyGenerator.prototype);
+
+fn = Reflect.construct(MyGenerator, [], MyGenerator);
+assertEq(fn instanceof MyGenerator, true);
+assertEq(fn instanceof GeneratorFunction, true);
+assertEq(Object.getPrototypeOf(fn), MyGenerator.prototype);
+
+fn = Reflect.construct(MyGenerator, [], GeneratorFunction);
+assertEq(fn instanceof MyGenerator, false);
+assertEq(fn instanceof GeneratorFunction, true);
+assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);
+
+
+// Set a different constructor as NewTarget.
+fn = Reflect.construct(MyGenerator, [], Array);
+assertEq(fn instanceof MyGenerator, false);
+assertEq(fn instanceof GeneratorFunction, false);
+assertEq(Object.getPrototypeOf(fn), Array.prototype);
+
+fn = Reflect.construct(GeneratorFunction, [], Array);
+assertEq(fn instanceof GeneratorFunction, false);
+assertEq(Object.getPrototypeOf(fn), Array.prototype);
+
+
+// The prototype defaults to %GeneratorFunctionPrototype% if null.
+function NewTargetNullPrototype() {}
+NewTargetNullPrototype.prototype = null;
+
+fn = Reflect.construct(GeneratorFunction, [], NewTargetNullPrototype);
+assertEq(fn instanceof GeneratorFunction, true);
+assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);
+
+fn = Reflect.construct(MyGenerator, [], NewTargetNullPrototype);
+assertEq(fn instanceof MyGenerator, false);
+assertEq(fn instanceof GeneratorFunction, true);
+assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);
+
+
+// "prototype" property is retrieved exactly once.
+var trapLog = [], getLog = [];
+var ProxiedConstructor = new Proxy(GeneratorFunction, new Proxy({
+    get(target, propertyKey, receiver) {
+        getLog.push(propertyKey);
+        return Reflect.get(target, propertyKey, receiver);
+    }
+}, {
+    get(target, propertyKey, receiver) {
+        trapLog.push(propertyKey);
+        return Reflect.get(target, propertyKey, receiver);
+    }
+}));
+
+fn = Reflect.construct(GeneratorFunction, [], ProxiedConstructor);
+assertEqArray(trapLog, ["get"]);
+assertEqArray(getLog, ["prototype"]);
+assertEq(fn instanceof GeneratorFunction, true);
+assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);
+
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);
diff --git a/js/src/tests/ecma_6/Generators/subclass.js b/js/src/tests/ecma_6/Generators/subclass.js
new file mode 100644
index 000000000..f93f4df4d
--- /dev/null
+++ b/js/src/tests/ecma_6/Generators/subclass.js
@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const GeneratorFunction = function*(){}.constructor;
+
+class MyGen extends GeneratorFunction {}
+
+// MyGen inherits from %GeneratorFunction%.
+assertEq(Object.getPrototypeOf(MyGen), GeneratorFunction);
+
+// MyGen.prototype inherits from %Generator%.
+assertEq(Object.getPrototypeOf(MyGen.prototype), GeneratorFunction.prototype);
+
+var fn = new MyGen("yield* [1, 2, 3]");
+
+// fn inherits from MyGen.prototype.
+assertEq(Object.getPrototypeOf(fn), MyGen.prototype);
+
+// fn.prototype inherits from %GeneratorPrototype%.
+assertEq(Object.getPrototypeOf(fn.prototype), GeneratorFunction.prototype.prototype);
+
+// Ensure the new generator function can be executed.
+var it = fn();
+
+// it inherits from fn.prototype.
+assertEq(Object.getPrototypeOf(it), fn.prototype);
+
+// Computes the expected result.
+assertEqArray([...it], [1, 2, 3]);
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);