fix(types): Use alternative Omit

Author: davidmatter

packages/dts-test/setupHelpers.test-d.ts

@@ -1,18 +1,18 @@
 import {
-  defineProps,
+  Ref,
+  Slots,
+  VNode,
+  defineComponent,
   defineEmits,
+  defineModel,
+  defineProps,
+  defineSlots,
   useAttrs,
+  useModel,
   useSlots,
-  withDefaults,
-  Slots,
-  defineSlots,
-  VNode,
-  Ref,
-  defineModel
+  withDefaults
 } from 'vue'
 import { describe, expectType } from './utils'
-import { defineComponent } from 'vue'
-import { useModel } from 'vue'
 
 describe('defineProps w/ type declaration', () => {
   // type declaration
@@ -100,6 +100,31 @@ describe('defineProps w/ union type declaration + withDefaults', () => {
   )
 })
 
+describe('defineProps w/ generic discriminate union + withDefaults', () => {
+  interface B {
+    b?: string
+  }
+  interface S<T> extends B {
+    mode: 'single'
+    v: T
+  }
+  interface M<T> extends B {
+    mode: 'multiple'
+    v: T[]
+  }
+  type Props = S<string> | M<string>
+  const props = withDefaults(defineProps<Props>(), {
+    b: 'b'
+  })
+
+  if (props.mode === 'single') {
+    expectType<string>(props.v)
+  }
+  if (props.mode === 'multiple') {
+    expectType<string[]>(props.v)
+  }
+})
+
 describe('defineProps w/ generic type declaration + withDefaults', <T extends
   number, TA extends {
   a: string

packages/runtime-core/src/apiSetupHelpers.ts

@@ -1,16 +1,18 @@
+import { Ref, ref } from '@vue/reactivity'
 import {
-  isArray,
-  isPromise,
-  isFunction,
   Prettify,
   UnionToIntersection,
-  extend
+  extend,
+  isArray,
+  isFunction,
+  isPromise
 } from '@vue/shared'
+import { watch } from './apiWatch'
 import {
-  getCurrentInstance,
-  setCurrentInstance,
   SetupContext,
   createSetupContext,
+  getCurrentInstance,
+  setCurrentInstance,
   unsetCurrentInstance
 } from './component'
 import { EmitFn, EmitsOptions, ObjectEmitsOptions } from './componentEmits'
@@ -21,16 +23,14 @@ import {
   MethodOptions
 } from './componentOptions'
 import {
-  ComponentPropsOptions,
   ComponentObjectPropsOptions,
+  ComponentPropsOptions,
   ExtractPropTypes,
   NormalizedProps,
   PropOptions
 } from './componentProps'
-import { warn } from './warning'
 import { SlotsType, StrictUnwrapSlotsType } from './componentSlots'
-import { Ref, ref } from '@vue/reactivity'
-import { watch } from './apiWatch'
+import { warn } from './warning'
 
 // dev only
 const warnRuntimeUsage = (method: string) =>
@@ -293,11 +293,16 @@ type InferDefault<P, T> =
   | ((props: P) => T & {})
   | (T extends NativeType ? T : never)
 
+// https://github.com/vuejs/core/issues/9335
+type OmitKeepDiscriminatedUnion<T, K extends keyof any> = T extends any
+  ? Pick<T, Exclude<keyof T, K>>
+  : never
+
 type PropsWithDefaults<
   T,
   Defaults extends InferDefaults<T>,
   BKeys extends keyof T
-> = Omit<T, keyof Defaults> & {
+> = OmitKeepDiscriminatedUnion<T, keyof Defaults> & {
   [K in keyof Defaults]-?: K extends keyof T
     ? Defaults[K] extends undefined
       ? T[K]