babel/lib/6to5/transformation/transformers/optional-classes-fast-super.js
2015-01-12 10:19:22 +11:00

75 lines
2.2 KiB
JavaScript

var traverse = require("../../traverse");
var util = require("../../util");
var t = require("../../types");
exports.optional = true;
exports.Class = function (node) {
var superClass = node.superClass || t.identifier("Function");
var hasConstructor = false;
var body = node.body.body;
for (var i in body) {
var methodNode = body[i];
hasConstructor = hasConstructor || methodNode.key.name === "constructor";
traverse(methodNode, {
enter: function (node, parent) {
if (t.isIdentifier(node, { name: "super" })) {
return superIdentifier(superClass, methodNode, node, parent);
} else if (t.isCallExpression(node)) {
var callee = node.callee;
if (!t.isMemberExpression(callee)) return;
if (callee.object.name !== "super") return;
// super.test(); -> ClassName.prototype.MethodName.call(this);
t.appendToMemberExpression(callee, t.identifier("call"));
node.arguments.unshift(t.thisExpression());
}
}
});
}
if (node.superClass && !hasConstructor) {
body.unshift(t.methodDefinition(
t.identifier("constructor"),
util.template("class-super-constructor-call-fast", {
SUPER_NAME: superClass
})
));
}
};
var superIdentifier = function (superClass, methodNode, id, parent) {
var methodName = methodNode.key;
if (parent.property === id) {
return;
} else if (t.isCallExpression(parent, { callee: id })) {
// super(); -> ClassName.prototype.MethodName.call(this);
parent.arguments.unshift(t.thisExpression());
if (methodName.name === "constructor") {
// constructor() { super(); }
return t.memberExpression(superClass, t.identifier("call"));
} else {
id = superClass;
// foo() { super(); }
if (!methodNode.static) {
id = t.memberExpression(id, t.identifier("prototype"));
}
id = t.memberExpression(id, methodName, methodNode.computed);
return t.memberExpression(id, t.identifier("call"));
}
} else if (t.isMemberExpression(parent) && !methodNode.static) {
// super.test -> ClassName.prototype.test
return t.memberExpression(superClass, t.identifier("prototype"));
} else {
return superClass;
}
};