Using Map with Typescript

[Gerasimov94]

Hello, i found an interesting issue. When i am passing an object in Map it works fine:

import {Map} from 'immutable';
...
const myMap = Map({a: 1});

But when i am trying to pass an array like on screen below, compiler complains:

const myMap = Map([[ "key", "value" ]]);

I took a that variant from here: https://immutable-js.github.io/immutable-js/docs/#/Map/Map

Argument of type 'string[][]' is not assignable to parameter of type '{ [key: string]: {}; }'. Index signature is missing in type 'string[][]'

In my opinion, it works that way because we have an overloaded Map functions at definitions file, and typescript choosing second variant instead of first.

  immutable-nonambient.d.ts: 761

  export function Map<K, V>(collection: Iterable<[K, V]>): Map<K, V>;
  export function Map<V>(obj: {[key: string]: V}): Map<string, V>;

ts version: 3.3.333333

[vamshi-tg]

Facing same problem. Created this csb for reference https://codesandbox.io/s/immutable-map-typescript-issue-56t35

[vamshi-tg]

We can resolve the typescript error with the below steps.

const strTupleArr: [string, string][] = [["key", "value"]]
const myMap = Map(strTupleArr);

[jdeniau]

Thank you for your bug report. The immutable-js oss fork will soon be merged and a fix for this issue has been included in #1833. Once this PR is merged, this issue will be resolved in the main branch. We will then do our best to to release the 4.0.0 version.

[jdeniau]

Hi!
The 4.0.0-rc.14 version has been released and should fix this issue.
Feel free to test it and re-open this issue if the issue is still present.
Thank you!

[ClusterH]

faced same error even though tried use 4.0.0-rc.14

[jdeniau]

@ClusterH can you try with the stable 4.0.0 and post a reproducible code snippet if there is the error is still present?