LibJS: Add initial support for Promises

SerenityOS · Apr 19, 2020 · 7497e04 · 7497e04
1 parent f38897e
commit 7497e04
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Showing 18 changed files with 907 additions and 2 deletions.
diff --git a/Libraries/LibJS/Forward.h b/Libraries/LibJS/Forward.h
@@ -34,6 +34,7 @@
     __JS_ENUMERATE(Function, function, FunctionPrototype, FunctionConstructor)   \
     __JS_ENUMERATE(NumberObject, number, NumberPrototype, NumberConstructor)     \
     __JS_ENUMERATE(Object, object, ObjectPrototype, ObjectConstructor)           \
+    __JS_ENUMERATE(Promise, promise, PromisePrototype, PromiseConstructor)       \
     __JS_ENUMERATE(StringObject, string, StringPrototype, StringConstructor)
 
 #define JS_ENUMERATE_ERROR_SUBCLASSES                                                                   \

diff --git a/Libraries/LibJS/Interpreter.cpp b/Libraries/LibJS/Interpreter.cpp
@@ -195,6 +195,14 @@ Value Interpreter::call(Function* function, Value this_value, Optional<MarkedVal
     return result;
 }
 
+Value Interpreter::call(Value value, Value this_value, Optional<MarkedValueList> arguments)
+{
+    if (!value.is_object() || !value.as_object().is_function())
+        return throw_exception<TypeError>(String::format("%s is not a function", value.to_string().characters()));
+    auto* function = static_cast<Function*>(&value.as_object());
+    return call(function, this_value, move(arguments));
+}
+
 Value Interpreter::throw_exception(Exception* exception)
 {
     if (exception->value().is_object() && exception->value().as_object().is_error()) {
@@ -223,4 +231,23 @@ const GlobalObject& Interpreter::global_object() const
     return static_cast<const GlobalObject&>(*m_global_object);
 }
 
+void Interpreter::enqueue_promise_job(PromiseReactionJob* job)
+{
+    // FIXME: Actually put job in a queue and execute *soon*, not *immediately*
+    //        Rules are here: https://tc39.es/ecma262/#job
+    job->execute(*this);
+}
+
+void Interpreter::promise_rejection_tracker(Promise* promise, Promise::RejectionOperation operation)
+{
+    switch (operation) {
+    case Promise::RejectionOperation::Reject:
+        dbg() << "Promise was rejected without any handlers (reason: " << promise->result() << ")";
+        break;
+    case Promise::RejectionOperation::Handle:
+        dbg() << "A handler was added to an already rejected promise (reason: " << promise->result() << ")";
+        break;
+    }
+}
+
 }
diff --git a/Libraries/LibJS/Interpreter.h b/Libraries/LibJS/Interpreter.h
@@ -35,6 +35,7 @@
 #include <LibJS/Runtime/Exception.h>
 #include <LibJS/Runtime/LexicalEnvironment.h>
 #include <LibJS/Runtime/MarkedValueList.h>
+#include <LibJS/Runtime/Promise.h>
 #include <LibJS/Runtime/Value.h>
 
 namespace JS {
@@ -102,6 +103,7 @@ class Interpreter {
     void exit_scope(const ScopeNode&);
 
     Value call(Function*, Value this_value = {}, Optional<MarkedValueList> arguments = {});
+    Value call(Value, Value this_value = {}, Optional<MarkedValueList> arguments = {});
 
     CallFrame& push_call_frame()
     {
@@ -160,6 +162,9 @@ class Interpreter {
 
     Value last_value() const { return m_last_value; }
 
+    void enqueue_promise_job(PromiseReactionJob*);
+    void promise_rejection_tracker(Promise*, Promise::RejectionOperation);
+
 private:
     Interpreter();
 

diff --git a/Libraries/LibJS/Makefile b/Libraries/LibJS/Makefile
@@ -37,6 +37,9 @@ OBJS = \
     Runtime/ObjectConstructor.o \
     Runtime/ObjectPrototype.o \
     Runtime/PrimitiveString.o \
+    Runtime/Promise.o \
+    Runtime/PromiseConstructor.o \
+    Runtime/PromisePrototype.o \
     Runtime/ScriptFunction.o \
     Runtime/Shape.o \
     Runtime/StringConstructor.o \

diff --git a/Libraries/LibJS/Runtime/FunctionConstructor.cpp b/Libraries/LibJS/Runtime/FunctionConstructor.cpp
@@ -71,7 +71,7 @@ Value FunctionConstructor::construct(Interpreter& interpreter)
     auto function_expression = parser.parse_function_node<FunctionExpression>();
     if (parser.has_errors()) {
         // FIXME: The parser should expose parsing error strings rather than just fprintf()'ing them
-        return Error::create(interpreter.global_object(), "SyntaxError", "");
+        return SyntaxError::create(interpreter.global_object(), "");
     }
     return function_expression->execute(interpreter);
 }

diff --git a/Libraries/LibJS/Runtime/GlobalObject.cpp b/Libraries/LibJS/Runtime/GlobalObject.cpp
@@ -49,6 +49,8 @@
 #include <LibJS/Runtime/Object.h>
 #include <LibJS/Runtime/ObjectConstructor.h>
 #include <LibJS/Runtime/ObjectPrototype.h>
+#include <LibJS/Runtime/PromiseConstructor.h>
+#include <LibJS/Runtime/PromisePrototype.h>
 #include <LibJS/Runtime/Shape.h>
 #include <LibJS/Runtime/StringConstructor.h>
 #include <LibJS/Runtime/StringPrototype.h>
@@ -104,6 +106,7 @@ void GlobalObject::initialize()
     add_constructor("Function", m_function_constructor, *m_function_prototype);
     add_constructor("Number", m_number_constructor, *m_number_prototype);
     add_constructor("Object", m_object_constructor, *m_object_prototype);
+    add_constructor("Promise", m_promise_constructor, *m_promise_prototype);
     add_constructor("String", m_string_constructor, *m_string_prototype);
 
 #define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \

diff --git a/Libraries/LibJS/Runtime/Object.h b/Libraries/LibJS/Runtime/Object.h
@@ -73,6 +73,7 @@ class Object : public Cell {
     virtual bool is_function() const { return false; }
     virtual bool is_native_function() const { return false; }
     virtual bool is_native_property() const { return false; }
+    virtual bool is_promise() const { return false; }
     virtual bool is_string_object() const { return false; }
 
     virtual const char* class_name() const override { return "Object"; }