add typescript definitions

README.md

@@ -116,6 +116,24 @@ const MyAppOpts = figgyPudding({
 })
 ```
 
+##### `opts`
+
+###### `other(key: String) -> Boolean`
+
+Additional keys can be allowed, if they pass the test in this function
+
+###### Example
+
+```javascript
+const MyOtherOpts = puddin({
+  a: {}
+}, {
+  other (key) { return /^special-/.test(key) }
+})
+```
+
+This will allow values that start with `special-`
+
 #### <a name="pudding-factory"></a> `> PuddingFactory(...providers) -> FiggyPudding{}`
 
 Instantiates an options object defined by `figgyPudding()`, which uses

index.d.ts

@@ -0,0 +1,72 @@
+
+declare function figgyPudding<
+  S extends figgyPudding.Specs = {},
+  O extends figgyPudding.Options = {}
+>(specs?: S, opts?: O): figgyPudding.PuddingFactory<S, O>
+
+declare module figgyPudding {
+  interface Options {
+    other?(key: string): boolean
+  }
+
+  type OtherOpt = Required<Pick<Options, 'other'>>
+
+  type Specs = {
+    [K in string]: string | Spec
+  }
+  interface Spec {
+    default?: any
+  }
+
+  type SpecWithDefault = Required<Pick<Spec, 'default'>>
+  type WidenPrimitive<T> =
+    T extends string ? string :
+    T extends number ? number :
+    T extends boolean ? boolean :
+    T
+  type SpecDefault<S> = S extends {default(): infer R} ? WidenPrimitive<R> : S extends {default: infer D} ? D : unknown
+
+  interface MapLike<K, V> {
+    get(key: K): V | undefined
+  }
+
+  type AvailableKeys<S, O> = O extends OtherOpt ? string : keyof S
+
+  type Proxy<S, O> = {
+    [K in keyof S]: SpecDefault<S[K]>
+  } & (O extends {other(key: string): boolean} ? {
+    [key: string]: unknown
+  } : {})
+
+  type ProxyFiggyPudding<S, O> = Readonly<Proxy<S, O>> & FiggyPudding<S, O>
+
+  type PuddingFactory<S, O> = (...providers: any[]) => ProxyFiggyPudding<S, O>
+
+  interface FiggyPuddingConstructor {
+    new <S extends Specs, O extends Options>(
+      specs: S, opts: O, providers: any[]
+    ): FiggyPudding<S, O>
+  }
+
+  interface FiggyPudding<S, O> {
+    readonly __isFiggyPudding: true
+    readonly [Symbol.toStringTag]: 'FiggyPudding'
+
+    get<K extends AvailableKeys<S, O>>(key: K): K extends keyof S ? SpecDefault<S[K]> : unknown
+    concat<P extends any[]>(...providers: P): ProxyFiggyPudding<S, O>
+    toJSON(): {
+      [K in AvailableKeys<S, O>]: K extends keyof S ? SpecDefault<S[K]> : unknown
+    }
+    forEach<This = this>(
+      fn: (this: This, value: unknown, key: AvailableKeys<S, O>, opts: this) => void,
+      thisArg?: This
+    ): void
+    entries(matcher: (key: string) => boolean): IterableIterator<[string, unknown]>
+    entries(): IterableIterator<[AvailableKeys<S, O>, unknown]>
+    [Symbol.iterator](): IterableIterator<[AvailableKeys<S, O>, unknown]>
+    keys(): IterableIterator<AvailableKeys<S, O>>
+    values(): IterableIterator<unknown>
+  }
+}
+
+export = figgyPudding

package.json

@@ -3,6 +3,7 @@
   "version": "3.5.1",
   "description": "Delicious, festive, cascading config/opts definitions",
   "main": "index.js",
+  "types": "index.d.ts",
   "files": [
     "*.js",
     "lib"

test/iteration.js

@@ -21,6 +21,11 @@ test('forEach', t => {
     [1, 'a', opts],
     [2, 'b', opts]
   ], 'correct arguments, and only declared props, in declared order')
+
+  opts.forEach(function () {
+    thisArg = this
+  })
+  t.equal(thisArg, opts, 'correct default this')
   t.done()
 })
 

tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "compilerOptions": {
+    "target": "es2015",
+    "strict": true
+  }
+}