@shopify/useful-types - npm Package Compare versions

Comparing version 2.1.5 to 2.2.0

CHANGELOG.md

@@ -8,4 +8,8 @@ # Changelog
 
-<!-- ## [Unreleased] -->
+## [2.2.0] - 2019-06-12
 
+### Added
+
+- Added the `ConstructorArguments`, `ConstructorArgumentAtIndex`, and `FirstConstructorArgument` type aliases
+
 ## [2.1.4] - 2019-01-27
@@ -12,0 +16,0 @@

dist/src/types.d.ts

@@ -32,3 +32,8 @@ export declare type ThenType<T> = T extends Promise<infer U> ? U : T;
 export declare type ExtendedWindow<T> = Window & typeof globalThis & T;
+export declare type ConstructorArguments<T> = T extends {
+    new (...args: infer U): any;
+} ? U : never;
+export declare type ConstructorArgumentAtIndex<T, I extends keyof ConstructorArguments<T>> = ConstructorArguments<T>[I];
+export declare type FirstConstructorArgument<T> = ConstructorArgumentAtIndex<T, 0>;
 export {};
 //# sourceMappingURL=types.d.ts.map

package.json

 {
   "name": "@shopify/useful-types",
-  "version": "2.1.5",
+  "version": "2.2.0",
   "license": "MIT",
@@ -5,0 +5,0 @@ "description": "A few handy TypeScript types",

README.md

@@ -44,2 +44,26 @@ # `@shopify/useful-types`
 
+- `ConstructorArgumentAtIndex<T, Index>`: Resolves to the type of the argument of the passed class's constructor at the passed index. Useful for cases where you wish to extract the type of arguments without actually exporting the argument types, and is a nice complement to TypeScript’s built-in `ReturnType`.
+
+  ```tsx
+  class SomeClass {
+    constructor(floop: string, doop: number) {
+      console.log(floop);
+    }
+  }
+
+  type DoopType = ConstructorArgument<typeof SomeClass, 1>; // number
+  ```
+
+- `FirstConstructorArgument<T>`: Resolves to the type of the first argument to the passed class's constructor. This is shorthand for `ConstructorArgumentAtIndex<T, 0>`.
+
+  ```ts
+  class SomeClass {
+    constructor(floop: string) {
+      console.log(floop);
+    }
+  }
+
+  type DoopType = FirstConstructorArgument<typeof SomeClass>; // string
+  ```
+
 - `ArrayElement<T>`: When `T` is an array, resolves to the type contained within the array.
@@ -46,0 +70,0 @@

No alert changes

Improved metrics

Total package byte prevSize

11095

16.83%

Lines of code

42

13.51%

Number of lines in readme file

108

28.57%

No dependency changes