LibJS: Implement Error function/constructor

Author: https://github.com/linusg
Commit: https://github.com/SerenityOS/serenity/commit/ee6472fef26
Pull-request: https://github.com/SerenityOS/serenity/pull/1568

Libraries/LibJS/Makefile

@@ -14,6 +14,7 @@ OBJS = \
     Runtime/DateConstructor.o \
     Runtime/DatePrototype.o \
     Runtime/Error.o \
+    Runtime/ErrorConstructor.o \
     Runtime/ErrorPrototype.o \
     Runtime/Exception.o \
     Runtime/Function.o \

Libraries/LibJS/Runtime/ErrorConstructor.cpp

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2020, Linus Groh <mail@linusgroh.de>
+ * 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/ErrorConstructor.h>
+
+namespace JS {
+
+ErrorConstructor::ErrorConstructor()
+{
+    put("prototype", interpreter().error_prototype());
+    put("length", Value(1));
+}
+
+ErrorConstructor::~ErrorConstructor()
+{
+}
+
+Value ErrorConstructor::call(Interpreter& interpreter)
+{
+    return construct(interpreter);
+}
+
+Value ErrorConstructor::construct(Interpreter& interpreter)
+{
+    String message = "";
+    if (!interpreter.call_frame().arguments.is_empty() && !interpreter.call_frame().arguments[0].is_undefined())
+        message = interpreter.call_frame().arguments[0].to_string();
+    return interpreter.heap().allocate<Error>("Error", message);
+}
+
+}

Libraries/LibJS/Runtime/ErrorConstructor.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2020, Linus Groh <mail@linusgroh.de>
+ * 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 ErrorConstructor final : public NativeFunction {
+public:
+    ErrorConstructor();
+    virtual ~ErrorConstructor() 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 "ErrorConstructor"; }
+};
+
+}

Libraries/LibJS/Runtime/GlobalObject.cpp

@@ -4,6 +4,7 @@
 #include <LibJS/Interpreter.h>
 #include <LibJS/Runtime/ConsoleObject.h>
 #include <LibJS/Runtime/DateConstructor.h>
+#include <LibJS/Runtime/ErrorConstructor.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/MathObject.h>
 #include <LibJS/Runtime/NativeFunction.h>
@@ -19,6 +20,7 @@ GlobalObject::GlobalObject()
 
     put("console", heap().allocate<ConsoleObject>());
     put("Date", heap().allocate<DateConstructor>());
+    put("Error", heap().allocate<ErrorConstructor>());
     put("Math", heap().allocate<MathObject>());
     put("Object", heap().allocate<ObjectConstructor>());
 }

Libraries/LibJS/Tests/Error.js

@@ -0,0 +1,29 @@
+function assert(x) { if (!x) throw 1; }
+
+try {
+    var e;
+
+    e = Error();
+    assert(e.name === "Error");
+    assert(e.message === "");
+
+    e = Error(undefined);
+    assert(e.name === "Error");
+    assert(e.message === "");
+
+    e = Error("test");
+    assert(e.name === "Error");
+    assert(e.message === "test");
+
+    e = Error(42);
+    assert(e.name === "Error");
+    assert(e.message === "42");
+
+    e = Error(null);
+    assert(e.name === "Error");
+    assert(e.message === "null");
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}