Why does TypeScript say a defined type is any when compiling

I am using using Angular 19, RxJS 7.8.2, and TypeScript 5.7.3 with the following options in my tsconfig.json file:

{
"compileOnSave": false,
"compilerOptions": {
"target": "ES2022",
"module": "ES2022",
"moduleResolution": "node",
"esModuleInterop": true,
"lib": ["ES2022", "dom"],
"forceConsistentCasingInFileNames": true,

"declaration": false,
"experimentalDecorators": true,
"importHelpers": true,
"outDir": "./dist/out-tsc",
"sourceMap": true,
"useDefineForClassFields": false,

"strict": true,
"allowUnreachableCode": false,
"noFallthroughCasesInSwitch": true,
"noImplicitOverride": true,
"noImplicitReturns": true,
"noPropertyAccessFromIndexSignature": true,
"noUncheckedIndexedAccess": true,
"strictNullChecks": false,
"strictPropertyInitialization": false
}
}


I recently got this build error which says there is an implicit any type, but in the same error is also shows that the implicit type is the correct type. I am pretty confused by this. For now I am using a //@ts-expect-error comment which allows it to compile just fine, but that feels wrong.



The code is basically set up so that a method returns an observable, and then I pipe the value through to something else, like this, where createDocument$() would return a type of Observable<IExtDocument>:

return this.someService.createDocument$(contract).pipe(
map((documentResponse) => { //<-- Error happens here
// Do stuff in here with the documentResponse
}
);


Even if I try and manually add the type definition with documentResponse: IExtDocument I get the following compilation error, which again shows the type but insists that it's actually any instead:

Application bundle generation failed. [5.222 seconds]

X [ERROR] TS7011: Function expression, which lacks return-type annotation, implicitly has an 'any' return type. [plugin angular-compiler]

src/app/path-redacted.component.ts:587:16:
587 │ map((documentResponse: IExtDocument) => {
╵ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Continue reading...