I have a piece of code that looks like this
const { Map } = require('immutable@4.0.0')
let map = new Map().setIn(["user",["alex","country"]],"Poland")
map.getIn(["user",["alex","country"])
I hope the above would return "Poland", but such is not the case. I presume
the reference type ["alex", "country"] is serialized differently when setting and querying. Any assistance on how to achieve this would be helpful. I shy away from having to handle the Array serialization manually
The array isn't serialized. immutable uses the actual object (its reference) as a key and the equal operator to compare keys. That means that the first ["alex","country"] and the second ["alex","country"] are two different keys.
This snippet shows the problem:
if (['alex', 'country'] !== ['alex', 'country']) {
console.log('The references are different');
}I have 3 solutions:
1. Store a reference in a variable
You can store a reference to the array in a variable to use it as a key:
const { Map } = require('immutable');
const arr = ['alex', 'country'];
let map = new Map().setIn(['user', arr], 'Poland');
console.log(map.getIn(['user', arr]));
2. Serialize the array using toString
An alternative solution is to serialize the arrays using toString:
const { Map } = require('immutable@4.0.0')
let map = new Map().setIn(["user",["alex","country"].toString()],"Poland")
map.getIn(["user",["alex","country"].toString()])
Example snippet:
if (['alex', 'country'].toString() === ['alex', 'country'].toString()) {
console.log('The serialized arrays are equal');
}But remember that serializing different arrays can yield the same string:
if (['alex', 'country'].toString() === ['alex,country'].toString()) {
console.log('Serializing different arrays can yield the same string');
}3. Flatten the array
Another approach is to flatten the path array:
const { Map } = require('immutable');
let map = new Map().setIn(['user', ['alex', 'country']].flat(), 'Poland');
console.log(map.getIn(['user', ['alex', 'country']].flat()));