Class 'Subject<T>' incorrectly extends base class 'Observable<T>' with TypeScript 2.4

[zoltantarcsay]

RxJS version:
5.4.1

Code to reproduce:
Save this line this to a TypeScript file (test.ts):
import {Subject} from 'rxjs/Subject';
Then compile:
tsc test.ts

Expected behavior:
No errors

Actual behavior:
Compilation error:

node_modules/rxjs/Subject.d.ts(16,22): error TS2415: Class 'Subject<T>' incorrectly extends base class 'Observable<T>'.
  Types of property 'lift' are incompatible.
    Type '<R>(operator: Operator<T, R>) => Observable<T>' is not assignable to type '<R>(operator: Operator<T, R>) => Observable<R>'.
      Type 'Observable<T>' is not assignable to type 'Observable<R>'.
        Type 'T' is not assignable to type 'R'.

Additional information:
TypeScript version: 2.4.1

TypeScript 2.4 introduced stricter checks for generics (see this blog post)

(Looks like this could be a typo in Observable#lift)

[kwonoj]

dupe of #2699 , #2539, #2700 . #2701 #2702 #2703 #2704

[grafox]

update TS. That's it

[ws6]

upgrade ts won't help. according to ts webpage, I added --noStrictGenericChecks to suppress the error message.

tsc --noStrictGenericChecks

[Argon2000]

Got this error WHEN i updated to TS 2.4.2

[Argon2000]

Fixed by updating RxJS to 5.4.2

[micaz]

@Argon2000
It Work for me, Thank You

[am0wa]

Didn't work for me with typescript 2.4.2 & RxJS 5.4.2
Started to work after the downgrading the typescript to 2.4.0

[am0wa]

@dearfog TypeScript to 2.4.0

[maximilian02]

I've deleted Rxjs node_module folder, and ran again npm install. That made the magic.

[theBull]

@AndrewMur I don't believe there is a Typescript version 5.4.0, latest version (as of right now) is 2.4.2 - perhaps you got it confused with the latest version of RxJS which is currently 5.4.3?

[am0wa]

@theBull srry for typo & confuse. Yeap I meant downgrade to typescript 2.4.0

[tramel-woodard]

Anyone installing from a package.json file, try changing your typescript devDependency from:
"typescript": "^2.0.3" to "typescript": "2.4.0" specifically.

Then delete the typescript package from your node_modules folder and then retry npm install.

[kwonoj]

I am seeing incorrect information's shared in this issue's comment - anyone still experiences compilation issue with LATEST RxJS, please confirm

1. if there are any other copy of RxJS v5 stays under node_modules which isn't latest, should be checked by physical lookup
2. if above is not case and compilation fail occurred with strict generic check on 2.4.2, confirm any user code inherits have correct type definition of base classes.

(check detail at #2726 (comment))

RxJS itself has fixed its own issue of library regarding this type definition issue and remaining failure mostly shoud be those cases listed above. If you're certain library has still failing, please don't hesitate to create new issue with repo have smallest code can reproduce issue.

I'm locking this issue itself to avoid further confusions.