Files
babel/src/babel/transformation/helpers/name-method.js

140 lines
3.9 KiB
JavaScript

import getFunctionArity from "./get-function-arity";
import * as util from "../../util";
import * as t from "../../types";
var visitor = {
enter(node, parent, scope, state) {
// check if this node is a referenced identifier that matches the same as our
// function id
if (!this.isReferencedIdentifier({ name: state.name })) return;
// check that we don't have a local variable declared as that removes the need
// for the wrapper
var localDeclar = scope.getBindingIdentifier(state.name);
if (localDeclar !== state.outerDeclar) return;
state.selfReference = true;
this.stop();
}
};
var wrap = function (state, method, id, scope) {
if (state.selfReference) {
var templateName = "property-method-assignment-wrapper";
if (method.generator) templateName += "-generator";
var template = util.template(templateName, {
FUNCTION: method,
FUNCTION_ID: id,
FUNCTION_KEY: scope.generateUidIdentifier(id.name)
});
template.callee._skipModulesRemap = true;
// shim in dummy params to retain function arity, if you try to read the
// source then you'll get the original since it's proxied so it's all good
var params = template.callee.body.body[0].params;
for (var i = 0, len = getFunctionArity(method); i < len; i++) {
params.push(scope.generateUidIdentifier("x"));
}
return template;
} else {
method.id = id;
return method;
}
};
var visit = function (node, name, scope) {
var state = {
selfAssignment: false,
selfReference: false,
outerDeclar: scope.getBindingIdentifier(name),
references: [],
name: name
};
// check to see if we have a local binding of the id we're setting inside of
// the function, this is important as there are caveats associated
var bindingInfo = scope.getOwnBindingInfo(name);
if (bindingInfo) {
if (bindingInfo.kind === "param") {
// safari will blow up in strict mode with code like:
//
// var t = function t(t) {};
//
// with the error:
//
// Cannot declare a parameter named 't' as it shadows the name of a
// strict mode function.
//
// this isn't to the spec and they've invented this behaviour which is
// **extremely** annoying so we avoid setting the name if it has a param
// with the same id
state.selfReference = true;
} else {
// otherwise it's defined somewhere in scope like:
//
// var t = function () {
// var t = 2;
// };
//
// so we can safely just set the id and move along as it shadows the
// bound function id
}
} else {
scope.traverse(node, visitor, state);
}
return state;
};
export function custom(node, id, scope) {
var state = visit(node, id.name, scope);
return wrap(state, node, id, scope);
}
export function property(node, file, scope) {
var key = t.toComputedKey(node, node.key);
if (!t.isLiteral(key)) return node; // we can't set a function id with this
var name = t.toIdentifier(key.value);
if (name === "eval" || name === "arguments") name = "_" + name;
var id = t.identifier(name);
var method = node.value;
var state = visit(method, name, scope);
node.value = wrap(state, method, id, scope);
}
export function bare(node, parent, scope) {
// has an `id` so we don't need to infer one
if (node.id) return node;
var id;
if (t.isProperty(parent) && parent.kind === "init" && (!parent.computed || t.isLiteral(parent.key))) {
// { foo() {} };
id = parent.key;
} else if (t.isVariableDeclarator(parent)) {
// var foo = function () {};
id = parent.id;
} else {
return node;
}
var name;
if (t.isLiteral(id)) {
name = id.value;
} else if (t.isIdentifier(id)) {
name = id.name;
} else {
return;
}
name = t.toIdentifier(name);
id = t.identifier(name);
var state = visit(node, name, scope);
return wrap(state, node, id, scope);
}