feat(types): infer expose type from SetupContext in defineComponent

packages-private/dts-test/defineComponent.test-d.tsx

@@ -3,6 +3,7 @@ import {
   type ComponentOptions,
   type ComponentPublicInstance,
   type PropType,
+  type Ref,
   type SetupContext,
   type Slots,
   type SlotsType,
@@ -12,6 +13,7 @@ import {
   h,
   reactive,
   ref,
+  shallowRef,
   withKeys,
   withModifiers,
 } from 'vue'
@@ -1175,6 +1177,37 @@ describe('componentOptions setup should be `SetupContext`', () => {
   )
 })
 
+describe('infer expose from `SetupContext`', () => {
+  // functional
+  const Baz = defineComponent(
+    <T,>(
+      props: { foo: T },
+      ctx: SetupContext<EmitsOptions, {}, { bar: Ref<T> }>,
+    ) => {
+      ctx.expose({ bar: shallowRef(props.foo) })
+      return () => <></>
+    },
+  )
+  const baz = new Baz({ foo: 1 })
+  expectType<IsAny<typeof baz.bar>>(false)
+  expectType<number>(baz.bar)
+
+  const Qux = defineComponent(
+    <T,>(
+      props: { foo: T },
+      ctx: {
+        expose: (exposed: { bar: Ref<T> }) => void
+      },
+    ) => {
+      ctx.expose({ bar: shallowRef(props.foo) })
+      return () => <></>
+    },
+  )
+  const qux = new Qux({ foo: 1 })
+  expectType<IsAny<typeof qux.bar>>(false)
+  expectType<number>(qux.bar)
+})
+
 describe('extract instance type', () => {
   const Base = defineComponent({
     props: {

packages/runtime-core/src/apiDefineComponent.ts

@@ -116,13 +116,14 @@ export type DefineSetupFnComponent<
   P extends Record<string, any>,
   E extends EmitsOptions = {},
   S extends SlotsType = SlotsType,
+  B extends Record<string, any> = {},
   Props = P & EmitsToProps<E>,
   PP = PublicProps,
 > = new (
   props: Props & PP,
 ) => CreateComponentPublicInstanceWithMixins<
   Props,
-  {},
+  B,
   {},
   {},
   {},
@@ -151,33 +152,35 @@ export function defineComponent<
   E extends EmitsOptions = {},
   EE extends string = string,
   S extends SlotsType = {},
+  B extends Record<string, any> = {},
 >(
   setup: (
     props: Props,
-    ctx: SetupContext<E, S>,
+    ctx: SetupContext<E, S, B>,
   ) => RenderFunction | Promise<RenderFunction>,
   options?: Pick<ComponentOptions, 'name' | 'inheritAttrs'> & {
     props?: (keyof NoInfer<Props>)[]
     emits?: E | EE[]
     slots?: S
   },
-): DefineSetupFnComponent<Props, E, S>
+): DefineSetupFnComponent<Props, E, S, B>
 export function defineComponent<
   Props extends Record<string, any>,
   E extends EmitsOptions = {},
   EE extends string = string,
   S extends SlotsType = {},
+  B extends Record<string, any> = {},
 >(
   setup: (
     props: Props,
-    ctx: SetupContext<E, S>,
+    ctx: SetupContext<E, S, B>,
   ) => RenderFunction | Promise<RenderFunction>,
   options?: Pick<ComponentOptions, 'name' | 'inheritAttrs'> & {
     props?: ComponentObjectPropsOptions<Props>
     emits?: E | EE[]
     slots?: S
   },
-): DefineSetupFnComponent<Props, E, S>
+): DefineSetupFnComponent<Props, E, S, B>
 
 // overload 2: defineComponent with options object, infer props from options
 export function defineComponent<

packages/runtime-core/src/component.ts

@@ -288,14 +288,13 @@ export type LifecycleHook<TFn = Function> = (TFn & SchedulerJob)[] | null
 export type SetupContext<
   E = EmitsOptions,
   S extends SlotsType = {},
+  Exposed extends Record<string, any> = Record<string, any>,
 > = E extends any
   ? {
       attrs: Attrs
       slots: UnwrapSlotsType<S>
       emit: EmitFn<E>
-      expose: <Exposed extends Record<string, any> = Record<string, any>>(
-        exposed?: Exposed,
-      ) => void
+      expose: (exposed?: Exposed) => void
     }
   : never