LibJS: Add String constructor :^)

Libraries/LibJS/Makefile

@@ -37,6 +37,7 @@ OBJS = \
     Runtime/PrimitiveString.o \
     Runtime/ScriptFunction.o \
     Runtime/Shape.o \
+    Runtime/StringConstructor.o \
     Runtime/StringObject.o \
     Runtime/StringPrototype.o \
     Runtime/Value.o \

Libraries/LibJS/Runtime/GlobalObject.cpp

@@ -39,6 +39,7 @@
 #include <LibJS/Runtime/NativeFunction.h>
 #include <LibJS/Runtime/NumberConstructor.h>
 #include <LibJS/Runtime/ObjectConstructor.h>
+#include <LibJS/Runtime/StringConstructor.h>
 #include <LibJS/Runtime/Value.h>
 
 namespace JS {
@@ -72,6 +73,7 @@ GlobalObject::GlobalObject()
     add_constructor("Function", m_function_constructor, *interpreter().function_prototype());
     add_constructor("Number", m_number_constructor, *interpreter().number_prototype());
     add_constructor("Object", m_object_constructor, *interpreter().object_prototype());
+    add_constructor("String", m_string_constructor, *interpreter().string_prototype());
 
 #define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
     add_constructor(#ClassName, m_##snake_name##_constructor, *interpreter().snake_name##_prototype());

Libraries/LibJS/Runtime/StringConstructor.cpp

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibJS/Interpreter.h>
+#include <LibJS/Runtime/Error.h>
+#include <LibJS/Runtime/StringConstructor.h>
+#include <LibJS/Runtime/StringObject.h>
+#include <math.h>
+
+namespace JS {
+
+StringConstructor::StringConstructor()
+{
+    put("prototype", interpreter().string_prototype());
+    put("length", Value(1));
+}
+
+StringConstructor::~StringConstructor()
+{
+}
+
+Value StringConstructor::call(Interpreter& interpreter)
+{
+    if (!interpreter.argument_count())
+        return js_string(interpreter, "");
+    return js_string(interpreter, interpreter.argument(0).to_string());
+}
+
+Value StringConstructor::construct(Interpreter& interpreter)
+{
+    PrimitiveString* primitive_string = nullptr;
+    if (!interpreter.argument_count())
+        primitive_string = js_string(interpreter, "");
+    else
+        primitive_string = js_string(interpreter, interpreter.argument(0).to_string());
+    return Value(interpreter.heap().allocate<StringObject>(primitive_string));
+}
+
+}

Libraries/LibJS/Runtime/StringConstructor.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibJS/Runtime/NativeFunction.h>
+
+namespace JS {
+
+class StringConstructor final : public NativeFunction {
+public:
+    StringConstructor();
+    virtual ~StringConstructor() override;
+
+    virtual Value call(Interpreter&) override;
+    virtual Value construct(Interpreter&) override;
+
+private:
+    virtual bool has_constructor() const override { return true; }
+    virtual const char* class_name() const override { return "StringConstructor"; }
+};
+
+}

Libraries/LibJS/Tests/String.prototype.js

@@ -1,8 +1,11 @@
 try {
-  assert(typeof Object.getPrototypeOf("") === "object");
-  assert(Object.getPrototypeOf("").valueOf() === '');
+    assert(typeof Object.getPrototypeOf("") === "object");
+    assert(Object.getPrototypeOf("").valueOf() === '');
 
-  console.log("PASS");
+    assert(typeof String.prototype === "object");
+    assert(String.prototype.valueOf() === '');
+
+    console.log("PASS");
 } catch (err) {
-  console.log("FAIL: " + err);
+    console.log("FAIL: " + err);
 }