ts: trying stuff to fix types

demo/tsconfig.json

@@ -7,6 +7,7 @@
     "esModuleInterop": false,
     "allowSyntheticDefaultImports": true,
     "strict": true,
+    "strictNullChecks": true,
     "forceConsistentCasingInFileNames": true,
     "module": "ESNext",
     "moduleResolution": "Node",
@@ -18,6 +19,5 @@
     "sourceMap": true,
     "plugins": [{ "name": "typescript-plugin-css-modules" }]
   },
-  "include": ["./src"],
-  "references": [{ "path": "./tsconfig.node.json" }]
+  "include": ["./src"]
 }

package.json

@@ -126,7 +126,7 @@
     "react-dom": "^18.2.0",
     "size-limit": "^8.0.1",
     "tsd": "^0.23.0",
-    "typescript": "^4.7.4",
+    "typescript": "^4.8.2",
     "vue": "^3.2.37"
   }
 }

packages/core/src/engines/Engine.ts

@@ -3,6 +3,8 @@ import { getEventDetails } from '../utils/events'
 import { call } from '../utils/fn'
 import { V, computeRubberband } from '../utils/maths'
 import { GestureKey, IngKey, Vector2 } from '../types'
+import { NonUndefined } from '../types'
+import { State } from '../types'
 
 /**
  * The lib doesn't compute the kinematics on the last event of the gesture
@@ -37,7 +39,7 @@ export interface Engine<Key extends GestureKey> {
    * `state._active` or `state._blocked` flags if the gesture isn't intentional.
    * @param event
    */
-  axisIntent?(event?: UIEvent): void
+  axisIntent?(event?: NonUndefined<State[Key]>['event']): void
 
   restrictToAxis?(movement: Vector2): void
 }
@@ -179,10 +181,7 @@ export abstract class Engine<Key extends GestureKey> {
    * Function ran at the start of the gesture.
    * @param event
    */
-  start(event: UIEvent) {
-    // TODO 28.08.22
-    // this should be the actual type of Event NonNullable<State[Key]>['event']
-    // but it now throws an error I'm not sure why
+  start(event: NonUndefined<State[Key]>['event']) {
     const state = this.state
     const config = this.config
     if (!state._active) {
@@ -225,7 +224,7 @@ export abstract class Engine<Key extends GestureKey> {
    * Computes all sorts of state attributes, including kinematics.
    * @param event
    */
-  compute(event?: UIEvent) {
+  compute(event?: NonUndefined<State[Key]>['event']) {
     const { state, config, shared } = this
     state.args = this.args
 

packages/core/src/types/state.ts

@@ -1,5 +1,5 @@
 import { GestureKey } from './config'
-import { Vector2, WebKitGestureEvent } from './utils'
+import { NonUndefined, Vector2, WebKitGestureEvent } from './utils'
 
 export type IngKey = 'dragging' | 'wheeling' | 'moving' | 'hovering' | 'scrolling' | 'pinching'
 
@@ -262,4 +262,4 @@ export interface State {
   pinch?: PinchState & { event: EventTypes['pinch'] }
 }
 
-export type FullGestureState<Key extends GestureKey> = SharedGestureState & NonNullable<State[Key]>
+export type FullGestureState<Key extends GestureKey> = SharedGestureState & NonUndefined<State[Key]>

packages/core/src/types/utils.ts

@@ -2,7 +2,7 @@ export type Vector2 = [number, number]
 export type WebKitGestureEvent = PointerEvent & { scale: number; rotation: number }
 export type Target = EventTarget | { current: EventTarget | null }
 export type PointerType = 'mouse' | 'touch' | 'pen'
-
+export type NonUndefined<T> = T extends undefined ? never : T
 // rip off from React types
 
 export type EventHandler<E extends Event = Event> = (event: E) => void