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Diffstat (limited to 'extension/lib/wallet/checkable.ts')
-rw-r--r-- | extension/lib/wallet/checkable.ts | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/extension/lib/wallet/checkable.ts b/extension/lib/wallet/checkable.ts new file mode 100644 index 000000000..7587f529c --- /dev/null +++ b/extension/lib/wallet/checkable.ts @@ -0,0 +1,136 @@ +/* + 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 + */ + +export 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; + } +} |