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Types not supported

Like any library bugs keep us company. When we find a non supported type we try our best to fix it. If it takes too much time to fix it we usually update this page.

ConditionalType

type TypeName<T> =
    T extends string ? "string" :
    T extends number ? "number" :
    T extends boolean ? "boolean" :
    T extends undefined ? "undefined" :
    T extends Function ? "function" :
    "object";
interface Test {
  conditional: TypeName<string>;
}
const mock = createMock<Test>();
mock.conditional // should be string. It will be null

Symbol Computed Property

const testSymbol: unique symbol = Symbol('aSymbol');
export interface WithSymbolComputed {
    [testSymbol]: string;
}
const mock = createMock<WithSymbolComputed>();
Object.getOwnPropertySymbols(mock); //it should return the symbol testSymbol

TsAutoMock will create a property with the random name generated by typescript (example __@aSymbol) instead of the correct symbol.

Extends Mapped Type

enum SOME_ENUM {
    FIRST = 'FIRST',
    SECOND = 'SECOND',
}
interface IBase {
    someField: string;
    anotherField: number;
}
interface InterfaceWithExtendsMappedType extends Record<SOME_ENUM, IBase[]> {}
const mock = createMock<InterfaceWithExtendsMappedType>();
mock.FIRST // undefined, it should be IBase[]
mock.SECOND // undefined, it should be IBase[]

issue Unfortunately this functionality doesnt work yet because when getting properties from an interface that extend a mapped type typescript returns a different type of property that is difficult to mock.

There is a branch created with a working version but it needs more investigation because the implementation is not readable and it may cause more issues link

Circular Generics

class C<T> {
  public propC: T
  public test: string
}
class A extends C<A> {
  public propA: number
}
const a: A = createMock<A>();
// This will fail because we will not support generics of the same type.
expect(a.propC.propC.test).toBe("");

These are discussed here: link. As of this writing, the problem with circular generics is that the generated AST will circle A over and over, and result in an infinite nested tree of declaration references. The intended behavior is to have the first back-reference stored elsewhere in the generated output and let it reference itself, making the runtime a lazy-evaluated sequence of getters.

Indexed access type with generics

interface StandardInterface {
    prop: string;
}
interface WithKeyGeneric<U extends keyof StandardInterface> {
    test(): StandardInterface[U];
}
const type = createMock<WithKeyGeneric<'prop'>>();
expect(type.test()).toBe(''); // it will be null

These are discussed here: link. Indexed access type it's a though feature to handle correctly. There are few difference scenarios:

From MappedTypes

type Test = {[key in keyof A]: A[key]};

From Generics -> example above
From literal