Class 'Subject<T>' incorrectly extends base class 'Observable<T> Nativescript navigation drawer error

Question

# This is the error I am facing now:

i downloaded navigation drawer sample using npm (https://github.com/shripalsoni04/nativescript-angular-drawer-template). but it gives the following error.

dhrn@dhrn-Inspiron-5548:~/NativeApp/Supervisor$ tns run android

Searching for devices...
iTunes is not available for this operating system. You will not be able to work with connected iOS devices.
Executing before-prepare hook from /home/dhrn/NativeApp/Supervisor/hooks/before-prepare/nativescript-dev-typescript.js
Found peer TypeScript 2.4.1
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'.

node_modules/tns-core-modules/ui/core/properties/properties.d.ts(48,14): error TS2559: Type 'Property<T, U>' has no properties in common with type 'TypedPropertyDescriptor<U>'.

node_modules/tns-core-modules/ui/core/properties/properties.d.ts(59,14): error TS2559: Type 'CoercibleProperty<T, U>' has no properties in common with type 'TypedPropertyDescriptor<U>'.

Unable to apply changes on device: 192.168.56.101:5555. Error is: TypeScript compiler failed with exit code 1.


```
**My configuration:**

```
{
    "description": "NativeScript Application",
    "license": "SEE LICENSE IN <your-license-filename>",
    "readme": "NativeScript Application",
    "repository": "<fill-your-repository-here>",
    "nativescript": {
        "id": "org.nativescript.supervisor",
        "tns-android": {
            "version": "3.1.1"
        }
    },
    "dependencies": {
        "@angular/common": "~4.0.0",
        "@angular/compiler": "~4.0.0",
        "@angular/core": "~4.0.0",
        "@angular/forms": "~4.0.0",
        "@angular/http": "~4.0.0",
        "@angular/platform-browser": "~4.0.0",
        "@angular/platform-browser-dynamic": "~4.0.0",
        "@angular/router": "~4.0.0",
        "nativescript-angular": "~3.0.0",
        "nativescript-telerik-ui": "^2.0.1",
        "nativescript-theme-core": "~1.0.4",
        "reflect-metadata": "~0.1.8",
        "rxjs": "~5.2.0",
        "tns-core-modules": "~3.0.0",
        "zone.js": "0.8.2"
    },
    "devDependencies": {
        "babel-traverse": "6.18.0",
        "babel-types": "6.18.0",
        "babylon": "6.13.1",
        "lazy": "1.0.11",
        "nativescript-dev-typescript": "^0.4.0",
        "typescript": "^2.3.2",
        "zone.js": "~0.7.2"
    }
}

Project Configuration:

dhrn@dhrn-Inspiron-5548:~/NativeApp/Supervisor$ tns info 
All NativeScript components versions information
┌──────────────────┬─────────────────┬────────────────┬───────────────┐
│ Component        │ Current version │ Latest version │ Information   │
│ nativescript     │ 3.1.1           │ 3.1.1          │ Up to date    │
│ tns-core-modules │ 3.1.0           │ 3.1.0          │ Up to date    │
│ tns-android      │ 3.1.1           │ 3.1.1          │ Up to date    │
│ tns-ios          │                 │ 3.1.0          │ Not installed │
└──────────────────┴─────────────────┴────────────────┴───────────────┘

Please kindly help me to fix this issue .

Electrocute

Possible duplicate of How do I get around this "Subject incorrectly extends Observable" error in TypeScript 2.4 and RxJS 5.x? – Knitting

Looks like a duplicate of #44810695. You can get around this with the noStrictGenericChecks compiler option. – Knitting

Answer 1

There are some issues with Microsoft/Typescript 2.4.1 update.
From the discussion in this issues page, it seems you need to use

configuration. Make sure, you actually have typescript 2.4.0 installed.
You can download it from here

Shankle

I needed to use typescript 2.3.4 – Stomatology

@jim in that case make sure you have it as "typescript": "2.3.4" not as "typescript": "^2.3.4" or "typescript": "~2.3.4", Refer to here, and again you should have this particular version installed – Shankle

i'm getting new error -> node_modules/tns-core-modules/ui/core/properties/properties.d.ts(48,14): error TS2559: Type 'Property<T, U>' has no properties in common with type 'TypedPropertyDescriptor<U>'. node_modules/tns-core-modules/ui/core/properties/properties.d.ts(59,14): error TS2559: Type 'CoercibleProperty<T, U>' has no properties in common with type 'TypedPropertyDescriptor<U>'. – Electrocute

@DharanG are you sure you are not referencing version Typescipt 2.4.1 as of now ..? Make sure the version number doesn't contain "^ or ~ " in package.json (for both rxjs: and typescript: ), in that case it will be upgrading and/or pointing to their higher versions, and not to the specific. Take a look here – Shankle

Answer 2

try this tsconfig.json

RxJS 6 will have this fixed, but as a temporary workaround, you can use the noStrictGenericChecks compiler option

"noStrictGenericChecks": true

{
  "compileOnSave": true,
  "compilerOptions": {
    "target": "es5",
    "module": "commonjs",
    "moduleResolution": "node",
    "sourceMap": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "lib": [ "es2015", "dom" ],
    "noImplicitAny": true,
    "suppressImplicitAnyIndexErrors": true,
    "noStrictGenericChecks": true 
  }
}

Waterresistant