d2-ui
Version:
375 lines (313 loc) • 10.6 kB
JavaScript
/*istanbul ignore next*/"use strict";
exports.__esModule = true;
var _typeof2 = require("babel-runtime/helpers/typeof");
var _typeof3 = _interopRequireDefault(_typeof2);
var _getIterator2 = require("babel-runtime/core-js/get-iterator");
var _getIterator3 = _interopRequireDefault(_getIterator2);
exports.evaluateTruthy = evaluateTruthy;
/*istanbul ignore next*/exports.evaluate = evaluate;
/*istanbul ignore next*/
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
// This file contains Babels metainterpreter that can evaluate static code.
/* eslint eqeqeq: 0 */
var VALID_CALLEES = ["String", "Number", "Math"]; /* eslint indent: 0 */
/* eslint max-len: 0 */
var INVALID_METHODS = ["random"];
/**
* Walk the input `node` and statically evaluate if it's truthy.
*
* Returning `true` when we're sure that the expression will evaluate to a
* truthy value, `false` if we're sure that it will evaluate to a falsy
* value and `undefined` if we aren't sure. Because of this please do not
* rely on coercion when using this method and check with === if it's false.
*
* For example do:
*
* if (t.evaluateTruthy(node) === false) falsyLogic();
*
* **AND NOT**
*
* if (!t.evaluateTruthy(node)) falsyLogic();
*
*/
function evaluateTruthy() {
var res = this.evaluate();
if (res.confident) return !!res.value;
}
/**
* Walk the input `node` and statically evaluate it.
*
* Returns an object in the form `{ confident, value }`. `confident` indicates
* whether or not we had to drop out of evaluating the expression because of
* hitting an unknown node that we couldn't confidently find the value of.
*
* Example:
*
* t.evaluate(parse("5 + 5")) // { confident: true, value: 10 }
* t.evaluate(parse("!true")) // { confident: true, value: false }
* t.evaluate(parse("foo + foo")) // { confident: false, value: undefined }
*
*/
function evaluate() {
var confident = true;
var deoptPath = /*istanbul ignore next*/void 0;
function deopt(path) {
if (!confident) return;
deoptPath = path;
confident = false;
}
var value = evaluate(this);
if (!confident) value = undefined;
return {
confident: confident,
deopt: deoptPath,
value: value
};
function evaluate(path) {
if (!confident) return;
/*istanbul ignore next*/var node = path.node;
if (path.isSequenceExpression()) {
var exprs = path.get("expressions");
return evaluate(exprs[exprs.length - 1]);
}
if (path.isStringLiteral() || path.isNumericLiteral() || path.isBooleanLiteral()) {
return node.value;
}
if (path.isNullLiteral()) {
return null;
}
if (path.isTemplateLiteral()) {
var str = "";
var i = 0;
var _exprs = path.get("expressions");
for ( /*istanbul ignore next*/var _iterator = node.quasis, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : (0, _getIterator3.default)(_iterator);;) {
/*istanbul ignore next*/
var _ref;
if (_isArray) {
if (_i >= _iterator.length) break;
_ref = _iterator[_i++];
} else {
_i = _iterator.next();
if (_i.done) break;
_ref = _i.value;
}
var elem = _ref;
// not confident, evaluated an expression we don't like
if (!confident) break;
// add on cooked element
str += elem.value.cooked;
// add on interpolated expression if it's present
var expr = _exprs[i++];
if (expr) str += String(evaluate(expr));
}
if (!confident) return;
return str;
}
if (path.isConditionalExpression()) {
var testResult = evaluate(path.get("test"));
if (!confident) return;
if (testResult) {
return evaluate(path.get("consequent"));
} else {
return evaluate(path.get("alternate"));
}
}
if (path.isExpressionWrapper()) {
// TypeCastExpression, ExpressionStatement etc
return evaluate(path.get("expression"));
}
// "foo".length
if (path.isMemberExpression() && !path.parentPath.isCallExpression({ callee: node })) {
var property = path.get("property");
var object = path.get("object");
if (object.isLiteral() && property.isIdentifier()) {
var _value = object.node.value;
var type = /*istanbul ignore next*/typeof _value === "undefined" ? "undefined" : (0, _typeof3.default)(_value);
if (type === "number" || type === "string") {
return _value[property.node.name];
}
}
}
if (path.isReferencedIdentifier()) {
var binding = path.scope.getBinding(node.name);
if (binding && binding.hasValue) {
return binding.value;
} else {
if (node.name === "undefined") {
return undefined;
} else if (node.name === "Infinity") {
return Infinity;
} else if (node.name === "NaN") {
return NaN;
}
var resolved = path.resolve();
if (resolved === path) {
return deopt(path);
} else {
return evaluate(resolved);
}
}
}
if (path.isUnaryExpression({ prefix: true })) {
if (node.operator === "void") {
// we don't need to evaluate the argument to know what this will return
return undefined;
}
var argument = path.get("argument");
if (node.operator === "typeof" && (argument.isFunction() || argument.isClass())) {
return "function";
}
var arg = evaluate(argument);
if (!confident) return;
switch (node.operator) {
case "!":
return !arg;
case "+":
return +arg;
case "-":
return -arg;
case "~":
return ~arg;
case "typeof":
return (/*istanbul ignore next*/typeof arg === "undefined" ? "undefined" : (0, _typeof3.default)(arg)
);
}
}
if (path.isArrayExpression()) {
var arr = [];
var elems = path.get("elements");
for ( /*istanbul ignore next*/var _iterator2 = elems, _isArray2 = Array.isArray(_iterator2), _i2 = 0, _iterator2 = _isArray2 ? _iterator2 : (0, _getIterator3.default)(_iterator2);;) {
/*istanbul ignore next*/
var _ref2;
if (_isArray2) {
if (_i2 >= _iterator2.length) break;
_ref2 = _iterator2[_i2++];
} else {
_i2 = _iterator2.next();
if (_i2.done) break;
_ref2 = _i2.value;
}
var _elem = _ref2;
_elem = _elem.evaluate();
if (_elem.confident) {
arr.push(_elem.value);
} else {
return deopt(_elem);
}
}
return arr;
}
if (path.isObjectExpression()) {
// todo
}
if (path.isLogicalExpression()) {
// If we are confident that one side of an && is false, or the left
// side of an || is true, we can be confident about the entire expression
var wasConfident = confident;
var left = evaluate(path.get("left"));
var leftConfident = confident;
confident = wasConfident;
var right = evaluate(path.get("right"));
var rightConfident = confident;
confident = leftConfident && rightConfident;
switch (node.operator) {
case "||":
// TODO consider having a "truthy type" that doesn't bail on
// left uncertainity but can still evaluate to truthy.
if (left && leftConfident) {
confident = true;
return left;
}
if (!confident) return;
return left || right;
case "&&":
if (!left && leftConfident || !right && rightConfident) {
confident = true;
}
if (!confident) return;
return left && right;
}
}
if (path.isBinaryExpression()) {
var _left = evaluate(path.get("left"));
if (!confident) return;
var _right = evaluate(path.get("right"));
if (!confident) return;
switch (node.operator) {
case "-":
return _left - _right;
case "+":
return _left + _right;
case "/":
return _left / _right;
case "*":
return _left * _right;
case "%":
return _left % _right;
case "**":
return (/*istanbul ignore next*/Math.pow(_left, _right)
);
case "<":
return _left < _right;
case ">":
return _left > _right;
case "<=":
return _left <= _right;
case ">=":
return _left >= _right;
case "==":
return _left == _right;
case "!=":
return _left != _right;
case "===":
return _left === _right;
case "!==":
return _left !== _right;
case "|":
return _left | _right;
case "&":
return _left & _right;
case "^":
return _left ^ _right;
case "<<":
return _left << _right;
case ">>":
return _left >> _right;
case ">>>":
return _left >>> _right;
}
}
if (path.isCallExpression()) {
var callee = path.get("callee");
var context = /*istanbul ignore next*/void 0;
var func = /*istanbul ignore next*/void 0;
// Number(1);
if (callee.isIdentifier() && !path.scope.getBinding(callee.node.name, true) && VALID_CALLEES.indexOf(callee.node.name) >= 0) {
func = global[node.callee.name];
}
if (callee.isMemberExpression()) {
var _object = callee.get("object");
var _property = callee.get("property");
// Math.min(1, 2)
if (_object.isIdentifier() && _property.isIdentifier() && VALID_CALLEES.indexOf(_object.node.name) >= 0 && INVALID_METHODS.indexOf(_property.node.name) < 0) {
context = global[_object.node.name];
func = context[_property.node.name];
}
// "abc".charCodeAt(4)
if (_object.isLiteral() && _property.isIdentifier()) {
var _type = /*istanbul ignore next*/(0, _typeof3.default)(_object.node.value);
if (_type === "string" || _type === "number") {
context = _object.node.value;
func = context[_property.node.name];
}
}
}
if (func) {
var args = path.get("arguments").map(evaluate);
if (!confident) return;
return func.apply(context, args);
}
}
deopt(path);
}
}