58 lines
1.4 KiB
TypeScript
58 lines
1.4 KiB
TypeScript
import fs from "fs"
|
|
|
|
// stateFromJSON returns a JSON file backed object. When object mutates, will
|
|
// serialize the object as JSON to the specified path.
|
|
//
|
|
// with recursive proxy support similar to:
|
|
//
|
|
// https://stackoverflow.com/questions/41299642/how-to-use-javascript-proxy-for-nested-objects
|
|
export function stateFromJSON<T extends Object>(
|
|
filepath: string,
|
|
defaultObject: T,
|
|
opts: {
|
|
replacer?: Function
|
|
reviver?: Function
|
|
} = {}
|
|
): T {
|
|
let root = defaultObject
|
|
|
|
try {
|
|
const data = fs.readFileSync(filepath, "utf8")
|
|
// TODO: support custom revive
|
|
root = JSON.parse(data, opts.reviver as any)
|
|
} catch (err) {}
|
|
|
|
function save() {
|
|
// should be sync to avoid write races
|
|
fs.writeFileSync(filepath, JSON.stringify(root, opts.replacer as any, 2))
|
|
}
|
|
|
|
const proxy = {
|
|
get(target, key) {
|
|
if (typeof target[key] === "object" && target[key] !== null) {
|
|
return new Proxy(target[key], proxy)
|
|
} else {
|
|
return target[key]
|
|
}
|
|
},
|
|
|
|
set(obj, prop, val) {
|
|
obj[prop] = val
|
|
save()
|
|
return true
|
|
},
|
|
}
|
|
|
|
return new Proxy(root, proxy) as T
|
|
}
|
|
|
|
// import { BigNumber } from "ethers";
|
|
// function jsonRevive(_key: string, val: any) {
|
|
// if (val && typeof val == "object") {
|
|
// if (val["type"] == "BigNumber") {
|
|
// return BigNumber.from(val["hex"]);
|
|
// }
|
|
// }
|
|
// return val;
|
|
// }
|