No idea who would I contact.

Using Typescript 3.4.1, React 16.8 and ArcGIS JS 4.11

I'm unable to compile when I added @types/arcgis-js-api, even when not using it.

Attached is a very simple typescript react.

It does nothing but unable to compile when @types/arcgis-js-api is installed.

Any suggestions?

Error output:

node_modules/@types/react/index.d.ts:100:31 - error TS2344: Type 'T' does not satisfy the constraint 'string | ((props: any) => ReactElement<any, string | ... | (new (props: any) => Component<any, any, any>)>) | (new (props: any) => Component<any, any, any>)'.
  Type 'string | number | ((props: any) => ReactElement<any, string | ... | (new (props: any) => Component<any, any, any>)>) | (new (props: any) => Component<any, any, any>)' is not assignable to type 'string | ((props: any) => ReactElement<any, string | ... | (new (props: any) => Component<any, any, any>)>) | (new (props: any) => Component<any, any, any>)'.
    Type 'number' is not assignable to type 'string | ((props: any) => ReactElement<any, string | ... | (new (props: any) => Component<any, any, any>)>) | (new (props: any) => Component<any, any, any>)'.
      Type 'T' is not assignable to type 'string'.
        Type 'string | number | ((props: any) => ReactElement<any, string | ... | (new (props: any) => Component<any, any, any>)>) | (new (props: any) => Component<any, any, any>)' is not assignable to type 'string'.
          Type 'number' is not assignable to type 'string'.
100     > extends ReactElement<P, T> { }‍‍‍‍‍‍‍‍

package.json

{
  "name": "test2",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  "author": "",
  "license": "ISC",
  "dependencies": {
    "react": "^16.8.6",
    "react-dom": "^16.8.6"
  "devDependencies": {
    "@types/arcgis-js-api": "^4.11.0",
    "@types/react": "^16.8.11",
    "@types/react-dom": "^16.8.3",
    "typescript": "^3.4.1"
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

tsconfig.json

{
  "compileOnSave": true,
  "compilerOptions": {
    "target": "es5",
    "module": "umd",
    "removeComments": true,
    "noEmitOnError": true,
    "sourceMap": true,
    "declaration": false,
    "jsx": "react",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "experimentalDecorators": true,
    "lib": ["dom", "scripthost", "es5", "es2015.promise", "es2015.core", "es2015.collection", "es2015.iterable"]   
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Hi Rene,

I'm using Typescript 3.8.3, and ArcGIS JS 4.15 and having similar issue in which the compiler reports errors as below on autocasting Color from string. The complied js works fine but it's a bit eyesore to have see this in VS code. I've added "skipLibCheck": true in the tsconfig.json within the compilerOptions but that didn't fix my problem.  wonder if you could help me. thanks.

view
  .when(() => {
    map.ground.navigationConstraint = { type: 'none' };
    map.ground.surfaceColor = '#fff';
    map.ground.opacity = 0.4;
    map.add(featureLayer);
  })‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

error

app/main.ts:104:5 - error TS2322: Type '"#fff"' is not assignable to type 'Color'.
104 map.ground.surfaceColor = '#fff';‍‍

tsconfig.json

{
  "compilerOptions": {
    "module": "amd",
    "noImplicitAny": true,
    "esModuleInterop": true,
    "sourceMap": true,
    "jsx": "react",
    "jsxFactory": "tsx",
    "target": "es5",
    "experimentalDecorators": true,
    "preserveConstEnums": true,
    "suppressImplicitAnyIndexErrors": true,
    "skipLibCheck": true
  "include": ["./app/*"],
  "exclude": ["node_modules"]
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍