Typescript - any of the types imported from a module

Question

Typescript - any of the types imported from a module

Currently, my code looks like this:

import * as Types from '../schema/types';

and I'm looking to achieve something along the lines of:

let a: Types;

This would signify that a should be one of the various types exported from the file types.ts. Is there a way to accomplish this? (By the way, it's for a graphql server)

typescript graphql

Answer 1

Answer №1

It appears that your goal is to implement union types. To define union types in TypeScript, you can follow the example below:

Scenario 1: Define individual types in a separate module and use unions when needed:

types.ts

type TypeA = {
    name: string;
}

type TypeB ={
    name: number;
}

export type {TypeA, TypeB}

You can then use these types like this:

import {TypeA, TypeB} from './types';

let myVar: TypeA | TypeB;

Or

import * as types from './types';

let myVar: types.TypeA | types.TypeB;

Scenario 2: Create union types directly in a module for ease of use:

types.ts

type TypeA = {
    name: string;
}

type TypeB ={
    id: string;
}

export type Types = TypeA | TypeB

To use them:

import {Types} from './types';

let myVar: Types;

If you need to utilize union types in GraphQL, check out the resources mentioned here.

Update: Regarding accessing all types within a module, it's not possible with interfaces or types as they are only compile-time entities for specifying object structures. Unlike classes, you cannot extract all types at runtime using methods like Object.keys or Object.entries.

Your best approach would be to define union types in the types file or create the union type directly there and import/use them in your main file.

Answer 2

It appears that your goal is to implement union types. To define union types in TypeScript, you can follow the example below:

Scenario 1: Define individual types in a separate module and use unions when needed:

types.ts

type TypeA = {
    name: string;
}

type TypeB ={
    name: number;
}

export type {TypeA, TypeB}

You can then use these types like this:

import {TypeA, TypeB} from './types';

let myVar: TypeA | TypeB;

Or

import * as types from './types';

let myVar: types.TypeA | types.TypeB;

Scenario 2: Create union types directly in a module for ease of use:

types.ts

type TypeA = {
    name: string;
}

type TypeB ={
    id: string;
}

export type Types = TypeA | TypeB

To use them:

import {Types} from './types';

let myVar: Types;

If you need to utilize union types in GraphQL, check out the resources mentioned here.

Update: Regarding accessing all types within a module, it's not possible with interfaces or types as they are only compile-time entities for specifying object structures. Unlike classes, you cannot extract all types at runtime using methods like Object.keys or Object.entries.

Your best approach would be to define union types in the types file or create the union type directly there and import/use them in your main file.

Answer 3

Answer №2

Automating this process may prove challenging, but the key solution lies in utilizing a union type.

If you have previously defined types in the file ../schema/types, such as:

interface Foo {
 ...
}

interface Bar {
 ...
}

You can import them using

import * as Types from '../schema/types';

Subsequently, you can create a union type like so:

type GqType = Types.Bar | Types.Foo;

Finally, by declaring a with this new type:

let a: GqType;

Answer 4

Automating this process may prove challenging, but the key solution lies in utilizing a union type.

If you have previously defined types in the file ../schema/types, such as:

interface Foo {
 ...
}

interface Bar {
 ...
}

You can import them using

import * as Types from '../schema/types';

Subsequently, you can create a union type like so:

type GqType = Types.Bar | Types.Foo;

Finally, by declaring a with this new type:

let a: GqType;

Typescript - any of the types imported from a module

Answer №1

Answer №2

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