feat: Added expose to component instances

packages/runtime-core/src/index.ts

@@ -90,7 +90,7 @@ export {
 
 // For getting a hold of the internal instance in setup() - useful for advanced
 // plugins
-export { getCurrentInstance } from './component'
+export { getCurrentInstance, getExposeProxy } from './component'
 
 // For raw render function users
 export { h } from './h'

packages/runtime-vapor/src/component.ts

@@ -1,6 +1,6 @@
-import { EffectScope, Ref, ref } from '@vue/reactivity'
+import { EffectScope, isRef, Ref, ref } from '@vue/reactivity'
 
-import { EMPTY_OBJ } from '@vue/shared'
+import { EMPTY_OBJ, isArray } from '@vue/shared'
 import { Block } from './render'
 import { type DirectiveBinding } from './directive'
 import {
@@ -11,6 +11,7 @@ import {
 
 import type { Data } from '@vue/shared'
 import { VaporLifecycleHooks } from './apiLifecycle'
+import { warn } from '@vue/runtime-core'
 
 export type Component = FunctionalComponent | ObjectComponent
 
@@ -42,6 +43,10 @@ export interface ComponentInternalInstance {
   props: Data
   setupState: Data
 
+  // exposed properties via expose()
+  exposed: Record<string, any> | null
+  exposeProxy: Record<string, any> | null
+
   /** directives */
   dirs: Map<Node, DirectiveBinding[]>
 
@@ -123,6 +128,54 @@ export const unsetCurrentInstance = () => {
   currentInstance = null
 }
 
+// TODO: Maybe it can be reused
+// TODO: https://github.com/vuejs/core/blob/04d2c05054c26b02fbc1d84839b0ed5cd36455b6/packages/runtime-core/src/component.ts#L186C1-L186C1
+export type SetupContext = {
+  expose: (exposed?: Record<string, any>) => void
+}
+
+// TODO: Maybe it can be reused
+// TODO: https://github.com/vuejs/core/blob/04d2c05054c26b02fbc1d84839b0ed5cd36455b6/packages/runtime-core/src/component.ts#L983
+export function createSetupContext(
+  instance: ComponentInternalInstance,
+): SetupContext {
+  const expose: SetupContext['expose'] = (exposed) => {
+    if (__DEV__) {
+      if (instance.exposed) {
+        warn(`expose() should be called only once per setup().`)
+      }
+      if (exposed != null) {
+        let exposedType: string = typeof exposed
+        if (exposedType === 'object') {
+          if (isArray(exposed)) {
+            exposedType = 'array'
+          } else if (isRef(exposed)) {
+            exposedType = 'ref'
+          }
+        }
+        if (exposedType !== 'object') {
+          warn(
+            `expose() should be passed a plain object, received ${exposedType}.`,
+          )
+        }
+      }
+    }
+    instance.exposed = exposed || {}
+  }
+
+  if (__DEV__) {
+    // We use getters in dev in case libs like test-utils overwrite instance
+    // properties (overwrites should not be done in prod)
+    return Object.freeze({
+      expose,
+    })
+  } else {
+    return {
+      expose,
+    }
+  }
+}
+
 let uid = 0
 export const createComponentInstance = (
   component: ObjectComponent | FunctionalComponent,
@@ -145,6 +198,10 @@ export const createComponentInstance = (
     props: EMPTY_OBJ,
     setupState: EMPTY_OBJ,
 
+    // exposed properties via expose()
+    exposed: null,
+    exposeProxy: null,
+
     dirs: new Map(),
 
     // lifecycle

packages/runtime-vapor/src/directive.ts

@@ -1,6 +1,7 @@
 import { isFunction } from '@vue/shared'
 import { currentInstance, type ComponentInternalInstance } from './component'
 import { effect } from './scheduler'
+import { getExposeProxy } from '@vue/runtime-core'
 
 export type DirectiveModifiers<M extends string = string> = Record<M, boolean>
 
@@ -69,6 +70,10 @@ export function withDirectives<T extends Node>(
   }
 
   const instance = currentInstance
+  // TODO: Wait for the component instance type to be completed before deleting `any`
+  const instanceProxy =
+    (getExposeProxy(currentInstance as any) as ComponentInternalInstance) ||
+    currentInstance.proxy
   if (!instance.dirs.has(node)) instance.dirs.set(node, [])
   const bindings = instance.dirs.get(node)!
 
@@ -84,7 +89,7 @@ export function withDirectives<T extends Node>(
 
     const binding: DirectiveBinding = {
       dir,
-      instance,
+      instance: instanceProxy,
       source,
       value: null, // set later
       oldValue: null,

packages/runtime-vapor/src/render.ts

@@ -4,6 +4,7 @@ import {
   type Component,
   type ComponentInternalInstance,
   createComponentInstance,
+  createSetupContext,
   setCurrentInstance,
   unsetCurrentInstance,
 } from './component'
@@ -42,7 +43,7 @@ export function mountComponent(
   setCurrentInstance(instance)
   const block = instance.scope.run(() => {
     const { component, props } = instance
-    const ctx = { expose: () => {} }
+    const ctx = createSetupContext(instance)
 
     const setupFn =
       typeof component === 'function' ? component : component.setup