wallet-core/extension/background/checkable.ts

137 lines
3.7 KiB
TypeScript

/*
This file is part of TALER
(C) 2016 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/>
*/
"use strict";
/**
* Decorators for type-checking JSON into
* an object.
* @module Checkable
* @author Florian Dold
*/
namespace Checkable {
let chkSym = Symbol("checkable");
function checkNumber(target, prop): any {
if ((typeof target) !== "number") {
throw Error("number expected for " + prop.propertyKey);
}
return target;
}
function checkString(target, prop): any {
if (typeof target !== "string") {
throw Error("string expected for " + prop.propertyKey);
}
return target;
}
function checkAnyObject(target, prop): any {
if (typeof target !== "object") {
throw Error("object expected for " + prop.propertyKey);
}
return target;
}
function checkValue(target, prop): any {
let type = prop.type;
if (!type) {
throw Error("assertion failed");
}
let v = target;
if (!v || typeof v !== "object") {
throw Error("expected object for " + prop.propertyKey);
}
let props = type.prototype[chkSym].props;
let remainingPropNames = new Set(Object.getOwnPropertyNames(v));
let obj = new type();
for (let prop of props) {
if (!remainingPropNames.has(prop.propertyKey)) {
throw Error("Property missing: " + prop.propertyKey);
}
if (!remainingPropNames.delete(prop.propertyKey)) {
throw Error("assertion failed");
}
let propVal = v[prop.propertyKey];
obj[prop.propertyKey] = prop.checker(propVal, prop);
}
if (remainingPropNames.size != 0) {
throw Error("superfluous properties " + JSON.stringify(Array.from(
remainingPropNames.values())));
}
return obj;
}
export function Class(target) {
target.checked = (v) => {
return checkValue(v, {
propertyKey: "(root)",
type: target,
checker: checkValue
});
};
return target;
}
export function Value(type) {
function deco(target: Object, propertyKey: string | symbol): void {
let chk = mkChk(target);
chk.props.push({
propertyKey: propertyKey,
checker: checkValue,
type: type
});
}
return deco;
}
export function List(type) {
function deco(target: Object, propertyKey: string | symbol): void {
throw Error("not implemented");
}
return deco;
}
export function Number(target: Object, propertyKey: string | symbol): void {
let chk = mkChk(target);
chk.props.push({propertyKey: propertyKey, checker: checkNumber});
}
export function AnyObject(target: Object, propertyKey: string | symbol): void {
let chk = mkChk(target);
chk.props.push({propertyKey: propertyKey, checker: checkAnyObject});
}
export function String(target: Object, propertyKey: string | symbol): void {
let chk = mkChk(target);
chk.props.push({propertyKey: propertyKey, checker: checkString});
}
function mkChk(target) {
let chk = target[chkSym];
if (!chk) {
chk = {props: []};
target[chkSym] = chk;
}
return chk;
}
}