fix(types): this type in data(), fix #570 (#576)

Author: antfu

src/component/componentOptions.ts

@@ -1,10 +1,8 @@
+import { VNode, ComponentOptions as Vue2ComponentOptions } from 'vue'
 import { Data } from './common'
 import { ComponentPropsOptions, ExtractPropTypes } from './componentProps'
-import { VNode } from 'vue'
 import { ComponentInstance, ComponentRenderProxy } from './componentProxy'
 
-import { ComponentOptions as Vue2ComponentOptions } from 'vue'
-
 export interface SetupContext {
   readonly attrs: Record<string, string>
   readonly slots: { [key: string]: (...args: any[]) => VNode[] }
@@ -43,12 +41,11 @@ interface ComponentOptionsBase<
   D = Data,
   C extends ComputedOptions = {},
   M extends MethodOptions = {}
->
-  extends Omit<
+> extends Omit<
     Vue2ComponentOptions<Vue, D, M, C, Props>,
     'data' | 'computed' | 'method' | 'setup' | 'props'
   > {
-  data?: (this: Props, vm: Props) => D
+  data?: (this: Props & Vue, vm: Props) => D
   computed?: C
   methods?: M
 }
@@ -70,7 +67,7 @@ export type ComponentOptionsWithProps<
   Props = ExtractPropTypes<PropsOptions>
 > = ComponentOptionsBase<Props, D, C, M> & {
   props?: PropsOptions
-  emits?: string[] | Record<string, null | ((emitData: any) => boolean) >
+  emits?: string[] | Record<string, null | ((emitData: any) => boolean)>
   setup?: SetupFunction<Props, RawBindings>
 } & ThisType<ComponentRenderProxy<Props, RawBindings, D, C, M>>
 

test-dts/defineComponent.test-d.ts

@@ -242,6 +242,7 @@ describe('type inference w/ options API', () => {
       // Limitation: we cannot expose the return result of setup() on `this`
       // here in data() - somehow that would mess up the inference
       expectType<number | undefined>(this.a)
+      expectType<Function>(this.$emit)
       return {
         c: this.a || 123,
       }