New function makeBrandString

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@glideapps/ts-necessities",
-    "version": "2.2.0",
+    "version": "2.2.1",
     "description": "Small utilities to make life with TypeScript easier",
     "main": "dist/index.js",
     "types": "dist/index.d.ts",

src/branded-strings.ts

@@ -13,6 +13,7 @@
  * let orange: Orange = apple;           // error!
  * orange = "jalapeño";                  // error!
  * let justAString: string = apple;      // This is ok
+ * ```
  */
 export type BrandedString<T extends string> = string & { __brand: T };
 
@@ -24,3 +25,19 @@ export type BrandedString<T extends string> = string & { __brand: T };
 export function brandString<T extends string>(s: string): BrandedString<T> {
     return s as BrandedString<T>;
 }
+
+/**
+ * Returns a function that brands a string with the specified brand.  For
+ * example:
+ *
+ * ```ts
+ * type Apple = BrandedString<"apple">;
+ * // `makeApple` will be of type `(s: string) => Apple`
+ * const makeApple = makeBrandString<Apple>();
+ * // `apple` will be of type `Apple`
+ * const apple = makeApple("Pink Lady");
+ * ```
+ */
+export function makeBrandString<T>(): T extends BrandedString<any> ? (s: string) => T : never {
+    return brandString as any;
+}

src/index.ts

@@ -177,4 +177,4 @@ export function exceptionToError(e: unknown): Error {
 
 export { DefaultMap, ReadonlyDefaultMap } from "./default-map";
 
-export { BrandedString, brandString } from "./branded-strings";
+export { BrandedString, brandString, makeBrandString } from "./branded-strings";