feat: improve TypeScript typings (#165)

* Update actions types

* Remove props from GetButtonPropsOptions

These props are not required for getButtonProps.

* Make getItemProps index optional

* Update state types

* Update DownshiftProps and A11StatusMessageOptions

Allow null in places where the docs say they can go. Add missing `itemCount` property.

* Remove version number from types

* Update contributors

* Address PR comments

* Rename `changes` back to `options`.
* Add optional arguments in the
right places.
* Use `Function` as type for `cb`.
* Use `object` ast type
for `otherStateToSet`.
* Fix incorrect name `setHighlightedItem` by
changing it to
`setHighlightedIndex`.

* Address updated PR comments

* Rename `A11StatusMessageOptions` to `A11yStatusMessageOptions`.
* Remove `ChangeOptions`.
* Remove `onClick` prop.

* Update README.md

.all-contributorsrc

@@ -243,6 +243,15 @@
         "doc",
         "ideas"
       ]
+    },
+    {
+      "login": "tansongyang",
+      "name": "Frank Tan",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/9488719?v=4",
+      "profile": "https://github.com/tansongyang",
+      "contributions": [
+        "code"
+      ]
     }
   ]
 }

README.md

@@ -554,7 +554,7 @@ Thanks goes to these people ([emoji key][emojis]):
 | :---: | :---: | :---: | :---: | :---: | :---: | :---: |
 | [<img src="https://avatars2.githubusercontent.com/u/15073300?v=4" width="100px;"/><br /><sub>monssef</sub>](https://github.com/rezof)<br />[💡](#example-rezof "Examples") | [<img src="https://avatars2.githubusercontent.com/u/5382443?v=4" width="100px;"/><br /><sub>Federico Zivolo</sub>](https://fezvrasta.github.io)<br />[📖](https://github.com/paypal/downshift/commits?author=FezVrasta "Documentation") | [<img src="https://avatars3.githubusercontent.com/u/746482?v=4" width="100px;"/><br /><sub>Divyendu Singh</sub>](https://divyendusingh.com)<br />[💡](#example-divyenduz "Examples") | [<img src="https://avatars1.githubusercontent.com/u/841955?v=4" width="100px;"/><br /><sub>Muhammad Salman</sub>](https://github.com/salmanmanekia)<br />[💻](https://github.com/paypal/downshift/commits?author=salmanmanekia "Code") | [<img src="https://avatars3.githubusercontent.com/u/10820159?v=4" width="100px;"/><br /><sub>João Alberto</sub>](https://twitter.com/psicotropidev)<br />[💻](https://github.com/paypal/downshift/commits?author=psicotropicos "Code") | [<img src="https://avatars0.githubusercontent.com/u/16327281?v=4" width="100px;"/><br /><sub>Bernard Lin</sub>](https://github.com/bernard-lin)<br />[💻](https://github.com/paypal/downshift/commits?author=bernard-lin "Code") [📖](https://github.com/paypal/downshift/commits?author=bernard-lin "Documentation") | [<img src="https://avatars1.githubusercontent.com/u/7330124?v=4" width="100px;"/><br /><sub>Geoff Davis</sub>](https://geoffdavis.info)<br />[💡](#example-geoffdavis92 "Examples") |
 | [<img src="https://avatars0.githubusercontent.com/u/3415488?v=4" width="100px;"/><br /><sub>Anup</sub>](https://github.com/reznord)<br />[📖](https://github.com/paypal/downshift/commits?author=reznord "Documentation") | [<img src="https://avatars0.githubusercontent.com/u/340520?v=4" width="100px;"/><br /><sub>Ferdinand Salis</sub>](http://ferdinandsalis.com)<br />[🐛](https://github.com/paypal/downshift/issues?q=author%3Aferdinandsalis "Bug reports") [💻](https://github.com/paypal/downshift/commits?author=ferdinandsalis "Code") | [<img src="https://avatars2.githubusercontent.com/u/662750?v=4" width="100px;"/><br /><sub>Kye Hohenberger</sub>](https://github.com/tkh44)<br />[🐛](https://github.com/paypal/downshift/issues?q=author%3Atkh44 "Bug reports") | [<img src="https://avatars0.githubusercontent.com/u/1443499?v=4" width="100px;"/><br /><sub>Julien Goux</sub>](https://github.com/jgoux)<br />[🐛](https://github.com/paypal/downshift/issues?q=author%3Ajgoux "Bug reports") [💻](https://github.com/paypal/downshift/commits?author=jgoux "Code") [⚠️](https://github.com/paypal/downshift/commits?author=jgoux "Tests") | [<img src="https://avatars2.githubusercontent.com/u/9586897?v=4" width="100px;"/><br /><sub>Joachim Seminck</sub>](https://github.com/jseminck)<br />[💻](https://github.com/paypal/downshift/commits?author=jseminck "Code") | [<img src="https://avatars3.githubusercontent.com/u/954596?v=4" width="100px;"/><br /><sub>Jesse Harlin</sub>](http://jesseharlin.net/)<br />[🐛](https://github.com/paypal/downshift/issues?q=author%3Athe-simian "Bug reports") [💡](#example-the-simian "Examples") | [<img src="https://avatars0.githubusercontent.com/u/1402095?v=4" width="100px;"/><br /><sub>Matt Parrish</sub>](https://github.com/pbomb)<br />[🔧](#tool-pbomb "Tools") |
-| [<img src="https://avatars1.githubusercontent.com/u/11661846?v=4" width="100px;"/><br /><sub>thom</sub>](http://thom.kr)<br />[💻](https://github.com/paypal/downshift/commits?author=thomhos "Code") | [<img src="https://avatars2.githubusercontent.com/u/1088312?v=4" width="100px;"/><br /><sub>Vu Tran</sub>](http://twitter.com/tranvu)<br />[💻](https://github.com/paypal/downshift/commits?author=vutran "Code") | [<img src="https://avatars1.githubusercontent.com/u/74193?v=4" width="100px;"/><br /><sub>Codie Mullins</sub>](https://github.com/codiemullins)<br />[💻](https://github.com/paypal/downshift/commits?author=codiemullins "Code") [💡](#example-codiemullins "Examples") | [<img src="https://avatars3.githubusercontent.com/u/12202757?v=4" width="100px;"/><br /><sub>Mohammad Rajabifard</sub>](https://morajabi.me)<br />[📖](https://github.com/paypal/downshift/commits?author=morajabi "Documentation") [🤔](#ideas-morajabi "Ideas, Planning, & Feedback") |
+| [<img src="https://avatars1.githubusercontent.com/u/11661846?v=4" width="100px;"/><br /><sub>thom</sub>](http://thom.kr)<br />[💻](https://github.com/paypal/downshift/commits?author=thomhos "Code") | [<img src="https://avatars2.githubusercontent.com/u/1088312?v=4" width="100px;"/><br /><sub>Vu Tran</sub>](http://twitter.com/tranvu)<br />[💻](https://github.com/paypal/downshift/commits?author=vutran "Code") | [<img src="https://avatars1.githubusercontent.com/u/74193?v=4" width="100px;"/><br /><sub>Codie Mullins</sub>](https://github.com/codiemullins)<br />[💻](https://github.com/paypal/downshift/commits?author=codiemullins "Code") [💡](#example-codiemullins "Examples") | [<img src="https://avatars3.githubusercontent.com/u/12202757?v=4" width="100px;"/><br /><sub>Mohammad Rajabifard</sub>](https://morajabi.me)<br />[📖](https://github.com/paypal/downshift/commits?author=morajabi "Documentation") [🤔](#ideas-morajabi "Ideas, Planning, & Feedback") | [<img src="https://avatars3.githubusercontent.com/u/9488719?v=4" width="100px;"/><br /><sub>Frank Tan</sub>](https://github.com/tansongyang)<br />[💻](https://github.com/paypal/downshift/commits?author=tansongyang "Code") |
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
 This project follows the [all-contributors][all-contributors] specification.

typings/index.d.ts

@@ -2,24 +2,24 @@ import * as React from 'react';
 
 export interface DownshiftProps {
     children: ChildrenFunction;
-    defaultHighlightedIndex?: number;
+    defaultHighlightedIndex?: number | null;
     defaultSelectedItem?: any;
     defaultInputValue?: string;
     defaultIsOpen?: boolean;
-    getA11yStatusMessage?: (options: A11StatusMessageOptions) => any;
+    getA11yStatusMessage?: (options: A11yStatusMessageOptions) => any;
     itemToString?: (item: any) => string;
     onChange?: (selectedItem: any, stateAndHelpers: ControllerStateAndHelpers) => void;
     onStateChange?: (options: StateChangeOptions, stateAndHelpers: ControllerStateAndHelpers) => void;
     onUserAction?: (options: StateChangeOptions, stateAndHelpers: ControllerStateAndHelpers) => void;
-    onClick?: Function;
+    itemCount?: number;
     selectedItem?: any;
     isOpen?: boolean;
     inputValue?: string;
     highlightedIndex?: number;
 }
 
-export interface A11StatusMessageOptions {
-    highlightedIndex: number;
+export interface A11yStatusMessageOptions {
+    highlightedIndex: number | null;
     highlightedValue: any;
     inputValue: string;
     isOpen: boolean;
@@ -29,11 +29,6 @@ export interface A11StatusMessageOptions {
     selectedItem: any;
 }
 
-export interface ChangeOptions {
-    selectedItem: any;
-    previousItem: any;
-}
-
 export interface StateChangeOptions {
     highlightedIndex: number;
     inputValue: string;
@@ -49,30 +44,14 @@ export interface GetInputPropsOptions extends React.HTMLProps<HTMLInputElement>
 
 export interface GetLabelPropsOptions extends React.HTMLProps<HTMLLabelElement> { }
 
-export interface GetButtonPropsOptions extends React.HTMLProps<HTMLButtonElement> {
-    // actions
-    clearSelection: () => void;
-    closeMenu: () => void;
-    openMenu: () => void;
-    selectHighlightedItem: () => void;
-    selectItem: (item: any) => void;
-    selectItemAtIndex: (index: number) => void;
-    setHighlightedIndex: (index: number) => void;
-    toggleMenu: (state: boolean) => void;
-
-    // state
-    highlightedIndex: number;
-    inputValue: string;
-    isOpen: boolean;
-    selectedItem: any;
-}
+export interface GetButtonPropsOptions extends React.HTMLProps<HTMLButtonElement> { }
 
 interface OptionalExtraGetItemPropsOptions {
     [key: string]: any;
 }
 
 export interface GetItemPropsOptions extends OptionalExtraGetItemPropsOptions {
-    index: number;
+    index?: number;
     item: any;
 }
 
@@ -85,18 +64,20 @@ export interface ControllerStateAndHelpers {
     getItemProps: (options: GetItemPropsOptions) => any;
 
     // actions
-    openMenu: () => void;
-    closeMenu: () => void;
-    toggleMenu: () => void;
-    selectItem: (item: any) => void;
-    selectItemAtIndex: (index: number) => void;
-    selectHighlightedItem: (index: number) => void;
-    setHighlightedItem: (index: number) => void;
-    clearSelection: () => void;
+    openMenu: (cb?: Function) => void;
+    closeMenu: (cb?: Function) => void;
+    toggleMenu: (cb?: Function) => void;
+    selectItem: (item: any, otherStateToSet?: object, cb?: Function) => void;
+    selectItemAtIndex: (index: number, otherStateToSet?: object, cb?: Function) => void;
+    selectHighlightedItem: (otherStateToSet?: object, cb?: Function) => void;
+    setHighlightedIndex: (index: number, otherStateToSet?: object, cb?: Function) => void;
+    clearSelection: (cb?: Function) => void;
+    reset: (otherStateToSet?: object, cb?: Function) => void;
+    itemToString: (item: any) => void;
 
     // state
-    highlightedIndex: number;
-    inputValue: string;
+    highlightedIndex: number | null;
+    inputValue: string | null;
     isOpen: boolean;
     selectedItem: any;
 }