TS thinks spreading Map into object still has Map properties

[elramus]

Bug Report

🔎 Search Terms

Map
Spread

🕗 Version & Regression Information

Not sure when it started, testing on current version. Same behavior observed in Nightly.

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about Maps.

⏯ Playground Link

Playground link

💻 Code

const myMap = new Map([
  ['foo', 'bar']
])

// TS thinks this is a Map, but it's not.
const myNewMap = { ...myMap }

// myNewMap.get is not a function 
myNewMap.get('foo') 

🙁 Actual behavior

TypeScript thinks get will be present, along with all the other Map properties. Running the code crashes though, because spreading the Map into the object yields an object.

🙂 Expected behavior

I'm not sure if TS mistakenly thinks the new object is a Map, or if is mistakenly grabbing the properties of the Map class, but one way or another it seems like TS should know that that spreading a Map into an object means no more Map properties.

[RyanCavanaugh]

Duplicate #53747, etc

[elramus]

@RyanCavanaugh thanks