New: add TypeScript definitions

package.json

@@ -38,6 +38,7 @@
     "url": "http://github.com/developit/preact-css-transition-group/issues"
   },
   "license": "MIT",
+  "types": "src/index.d.ts",
   "devDependencies": {
     "babel-core": "^6.6.4",
     "babel-eslint": "^6.1.2",

src/index.d.ts

@@ -0,0 +1,58 @@
+declare module "preact-css-transition-group" {
+  import {
+    Component,
+    ComponentProps,
+    FunctionalComponent,
+    AnyComponent
+  } from "preact";
+
+  interface CSSTransitionGroupProps<
+    C extends Component<any, any> | FunctionalComponent<any>
+  > extends ComponentProps<C> {
+    transitionName: string;
+    /** Defaults to true. */
+    transitionEnter?: boolean;
+    /** Defaults to true. */
+    transitionLeave?: boolean;
+    transitionEnterTimeout?: number;
+    transitionLeaveTimeout?: number;
+
+    /**
+     * The Preact AnyComponent or DOM component string used to render the
+     * CSSTransitionGroup. Defaults to 'span'.
+     */
+    component?: AnyComponent<any, any> | string;
+
+    /**
+     * Any additional properties specified on the CSSTransitionGroup will be
+     * passed to component. e.g.:
+     *   <CSSTransitionGroup transitionName='foo' component='div' class='foo'
+     *     bar={1}>
+     *     ... children ...
+     *   </CSSTransitionGroup>
+     * Will render as:
+     *   <div class='foo' bar='1'>... children ...</div>
+     */
+    [name: string]: any;
+  }
+
+  // todo: import from Preact instead pending
+  // https://github.com/developit/preact/pull/869.
+  type ComponentChild = JSX.Element | string;
+  type ComponentChildren = ComponentChild[];
+
+  interface CSSTransitionGroupState {
+    children: ComponentChildren;
+  }
+
+  type Key = string | number | any;
+
+  export default abstract class CSSTransitionGroup extends Component<
+    CSSTransitionGroupProps<CSSTransitionGroup>,
+    any
+  > {
+    performEnter(key: Key): void;
+    performLeave(key: Key): void;
+    stop(key: Key): void;
+  }
+}