Get string template variables

getStringTemplateVariables.ts

// if you have a object like this
// {
//   tpl1: `Hello {name}, welcome to {location}`,
//   tpl2: `yo {bro}`,
// }
// and you wanna get a type like this
// {
//   name: string,
//   location: string,
//   bro: string
// }
type UnionToIntersection<U> = (U extends any ? (k: U) => void : never) extends ((k: infer I) => void) ? I : never;
type PickAndFlatten<T, K extends keyof T> = UnionToIntersection<T[K]>;
type GetTemplateVariables<T> = T extends '' ? {} :
    T extends `${infer P}{${infer B}}${infer S}` 
        ? { [T in B]: string } | GetTemplateVariables<S>
        : unknown;

// T extends `{${infer B}}${infer S}` ? GetAllTemplateVariables<S> : unknown;
type GetAllTemplateVariables<T> = {
    [P in keyof T]: GetTemplateVariables<T[P]>;
}

const t1 = {
    a: ` {var1} dfadf {var12} `,
    b: `{var2}`
} as const;

const t1Vars: PickAndFlatten<GetAllTemplateVariables<typeof t1>, keyof typeof t1> = {} as any;
// t1Vars: {
//     var1: string;
// } & {
//     var12: string;
// } & {
//     var2: string;
// }