import { Expression } from "../params"; /** * A type that splits literal string S with delimiter D. * * For example Split<"a/b/c", "/"> is ['a' | "b" | "c"] */ export type Split<S extends string, D extends string> = string extends S ? string[] : S extends "" ? [] : S extends `${D}${infer Tail}` ? [...Split<Tail, D>] : S extends `${infer Head}${D}${infer Tail}` ? string extends Head ? [...Split<Tail, D>] : [Head, ...Split<Tail, D>] : [ S ]; /** * A type that ensure that type S is not null or undefined. */ export type NullSafe<S extends null | undefined | string> = S extends null ? never : S extends undefined ? never : S extends string ? S : never; /** * A type that extracts parameter name enclosed in bracket as string. * Ignore wildcard matches * * For example, Extract<"{uid}"> is "uid". * For example, Extract<"{uid=*}"> is "uid". * For example, Extract<"{uid=**}"> is "uid". */ export type Extract<Part extends string> = Part extends `{${infer Param}=**}` ? Param : Part extends `{${infer Param}=*}` ? Param : Part extends `{${infer Param}}` ? Param : never; /** * A type that maps all parameter capture gropus into keys of a record. * For example, ParamsOf<"users/{uid}"> is { uid: string } * ParamsOf<"users/{uid}/logs/{log}"> is { uid: string; log: string } * ParamsOf<"some/static/data"> is {} * * For flexibility reasons, ParamsOf<string> is Record<string, string> */ export type ParamsOf<PathPattern extends string | Expression<string>> = PathPattern extends Expression<string> ? Record<string, string> : string extends PathPattern ? Record<string, string> : { [Key in Extract<Split<NullSafe<Exclude<PathPattern, Expression<string>>>, "/">[number]>]: string; };