types.d.ts

interface BasePrompt {
    name: string;
}

interface TextPrompt extends BasePrompt {
    type: 'text';
}

interface ConfirmPrompt extends BasePrompt {
    type: 'confirm';
}

interface SelectPrompt<Choices extends Readonly<Readonly<Choice>[]>> extends BasePrompt {
    type: 'select';
    choices: Choices;
}

interface MultiselectPrompt<Choices extends Readonly<Readonly<Choice>[]>> extends BasePrompt {
    type: 'multiselect';
    choices: Choices;
}

interface Choice {
    value: any;
    label: string;
    hint?: string;
}

type UnionToIntersection<U> = (U extends any ? (k: U) => void : never) extends ((k: infer I) => void) ? I : never

type Prompt = TextPrompt | ConfirmPrompt | SelectPrompt<Readonly<Choice[]>> | MultiselectPrompt<Readonly<Choice[]>>;

type Answer<T extends Prompt, Choices extends Readonly<Choice[]> = T extends SelectPrompt<infer C> ? C : T extends MultiselectPrompt<infer C> ? C : never> = T extends TextPrompt ? string : T extends ConfirmPrompt ? boolean : T extends SelectPrompt<Choices> ? Choices[number]['value'] : T extends MultiselectPrompt<Choices> ? (Choices[number]['value'] | undefined)[] : never;

type Answers<T extends Readonly<Prompt> | Readonly<Prompt[]>> = T extends Readonly<Prompt> ? Partial<{ [key in T['name']]: Answer<T> }> : T extends Readonly<Prompt[]> ? UnionToIntersection<Answers<T[number]>> : never;

interface PromptOptions {
    onSubmit?: () => any;
    onCancel?: () => any;
}

export default function prompt<T extends Readonly<Prompt> | Readonly<Prompt[]>>(questions: T, opts?: PromptOptions): Promise<Answers<T>>;