Search Terms
- getPromisedTypeOfPromise
- detect Promise
Suggestion
expose getPromisedTypeOfPromise in the TypeChecker API.
Use Cases
Writing lint rules with typechecking involving promises. One example is one checking the result of a yield in a generator. Since yields inside generators are not typed, being able to use linting to check types are properly annotated can be powerful.
Examples
// source code
const myAsyncFunc = async (num: number) => num;
function* gen() {
const y = yield call(myFunc);
}
call is a redux saga effect that has an API contract of calling a passed function and awaiting if it is a promise. Given this contract, its possible to write a lint rule instructing a consumer to annotate y with : number.
// lint rule
...
let returnType = appliedFunctionType.getCallSignatures()[0].getReturnType();
if(// is promise) {
returnType = typeChecker.getPromisedTypeOfPromise(returnType);
}
Checklist
My suggestion meets these guidelines:
Search Terms
Suggestion
expose
getPromisedTypeOfPromisein theTypeCheckerAPI.Use Cases
Writing lint rules with typechecking involving promises. One example is one checking the result of a yield in a generator. Since yields inside generators are not typed, being able to use linting to check types are properly annotated can be powerful.
Examples
callis a redux saga effect that has an API contract of calling a passed function and awaiting if it is a promise. Given this contract, its possible to write a lint rule instructing a consumer to annotateywith: number.Checklist
My suggestion meets these guidelines: