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Diffstat (limited to 'src/checkable.ts')
| -rw-r--r-- | src/checkable.ts | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/src/checkable.ts b/src/checkable.ts new file mode 100644 index 000000000..89d0c7150 --- /dev/null +++ b/src/checkable.ts @@ -0,0 +1,262 @@ +/* + 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, see <http://www.gnu.org/licenses/> + */ + + +"use strict"; + +/** + * Decorators for type-checking JSON into + * an object. + * @module Checkable + * @author Florian Dold + */ + +export namespace Checkable { + + type Path = (number | string)[]; + + interface SchemaErrorConstructor { + new (err: string): SchemaError; + } + + interface SchemaError { + name: string; + message: string; + } + + interface Prop { + propertyKey: any; + checker: any; + type: any; + elementChecker?: any; + elementProp?: any; + } + + export let SchemaError = (function SchemaError(message: string) { + this.name = 'SchemaError'; + this.message = message; + this.stack = (<any>new Error()).stack; + }) as any as SchemaErrorConstructor; + + + SchemaError.prototype = new Error; + + let chkSym = Symbol("checkable"); + + + function checkNumber(target: any, prop: Prop, path: Path): any { + if ((typeof target) !== "number") { + throw new SchemaError(`expected number for ${path}`); + } + return target; + } + + + function checkString(target: any, prop: Prop, path: Path): any { + if (typeof target !== "string") { + throw new SchemaError(`expected string for ${path}, got ${typeof target} instead`); + } + return target; + } + + + function checkAnyObject(target: any, prop: Prop, path: Path): any { + if (typeof target !== "object") { + throw new SchemaError(`expected (any) object for ${path}, got ${typeof target} instead`); + } + return target; + } + + + function checkAny(target: any, prop: Prop, path: Path): any { + return target; + } + + + function checkList(target: any, prop: Prop, path: Path): any { + if (!Array.isArray(target)) { + throw new SchemaError(`array expected for ${path}, got ${typeof target} instead`); + } + for (let i = 0; i < target.length; i++) { + let v = target[i]; + prop.elementChecker(v, prop.elementProp, path.concat([i])); + } + return target; + } + + + function checkOptional(target: any, prop: Prop, path: Path): any { + console.assert(prop.propertyKey); + prop.elementChecker(target, + prop.elementProp, + path.concat([prop.propertyKey])); + return target; + } + + + function checkValue(target: any, prop: Prop, path: Path): any { + let type = prop.type; + if (!type) { + throw Error(`assertion failed (prop is ${JSON.stringify(prop)})`); + } + let v = target; + if (!v || typeof v !== "object") { + throw new SchemaError( + `expected object for ${path.join(".")}, got ${typeof v} instead`); + } + 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)) { + if (prop.optional) { + continue; + } + throw new SchemaError("Property missing: " + prop.propertyKey); + } + if (!remainingPropNames.delete(prop.propertyKey)) { + throw new SchemaError("assertion failed"); + } + let propVal = v[prop.propertyKey]; + obj[prop.propertyKey] = prop.checker(propVal, + prop, + path.concat([prop.propertyKey])); + } + + if (remainingPropNames.size != 0) { + throw new SchemaError("superfluous properties " + JSON.stringify(Array.from( + remainingPropNames.values()))); + } + return obj; + } + + + export function Class(target: any) { + target.checked = (v: any) => { + return checkValue(v, { + propertyKey: "(root)", + type: target, + checker: checkValue + }, ["(root)"]); + }; + return target; + } + + + export function Value(type: any) { + if (!type) { + throw Error("Type does not exist yet (wrong order of definitions?)"); + } + 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: any) { + let stub = {}; + type(stub, "(list-element)"); + let elementProp = mkChk(stub).props[0]; + let elementChecker = elementProp.checker; + if (!elementChecker) { + throw Error("assertion failed"); + } + function deco(target: Object, propertyKey: string | symbol): void { + let chk = mkChk(target); + chk.props.push({ + elementChecker, + elementProp, + propertyKey: propertyKey, + checker: checkList, + }); + } + + return deco; + } + + + export function Optional(type: any) { + let stub = {}; + type(stub, "(optional-element)"); + let elementProp = mkChk(stub).props[0]; + let elementChecker = elementProp.checker; + if (!elementChecker) { + throw Error("assertion failed"); + } + function deco(target: Object, propertyKey: string | symbol): void { + let chk = mkChk(target); + chk.props.push({ + elementChecker, + elementProp, + propertyKey: propertyKey, + checker: checkOptional, + optional: true, + }); + } + + 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 Any(target: Object, + propertyKey: string | symbol): void { + let chk = mkChk(target); + chk.props.push({ + propertyKey: propertyKey, + checker: checkAny, + optional: true + }); + } + + + export function String(target: Object, propertyKey: string | symbol): void { + let chk = mkChk(target); + chk.props.push({ propertyKey: propertyKey, checker: checkString }); + } + + + function mkChk(target: any) { + let chk = target[chkSym]; + if (!chk) { + chk = { props: [] }; + target[chkSym] = chk; + } + return chk; + } +}
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