feat: Add Vue adapter (#416)

* chore: initial work at scaffolding Vue package

* chore: initial work on adding in useField and useForm API

* chore: fix build for Vue package

* chore: migrate to slots for functional comps

* chore: got initial fields rendering

* chore: add component names for debuggability

* chore: fix error regarding passdown props

* chore: fix Promise constructor error in demo

* chore: initial work at writing vue store implementation

* feat: add initial useStore and Subscribe instances

* fix: state is now passed as a dedicated reactive option

* chore: temporarily remove Vue 2 typechecking

* chore: make Provider and selector optional

* chore: add createFormFactory

* chore: attempt 1 of test - JSX

* chore: attempt 2 of test - Vue JSX

* chore: attempt 3 of test - H

* chore: migrate to proper h function

* chore: fix tests by bumping package

* chore: fix JSX typings

* chore: add another test for useForm

* chore: listen for fieldAPIs to update

* fix: fields should now update during mount

* chore: add test for useField in Vue

* test: add useField Vue tests

* docs: add early docs for Vue package

docs/config.json

@@ -93,6 +93,50 @@
           ]
         }
       ]
+    },
+    {
+      "framework": "vue",
+      "menuItems": [
+        {
+          "label": "Getting Started",
+          "children": [
+            {
+              "label": "Quick Start",
+              "to": "framework/vue/quick-start"
+            }
+          ]
+        },
+        {
+          "label": "API Reference",
+          "children": [
+            {
+              "label": "useForm",
+              "to": "framework/vue/reference/useForm"
+            },
+            {
+              "label": "useField",
+              "to": "framework/vue/reference/useField"
+            },
+            {
+              "label": "Field",
+              "to": "framework/vue/reference/Field"
+            },
+            {
+              "label": "FormApi",
+              "to": "framework/vue/reference/formApi"
+            }
+          ]
+        },
+        {
+          "label": "Examples",
+          "children": [
+            {
+              "label": "Simple",
+              "to": "framework/vue/examples/simple"
+            }
+          ]
+        }
+      ]
     }
   ]
 }

docs/framework/vue/quick-start.md

@@ -0,0 +1,46 @@
+---
+id: quick-start
+title: Quick Start
+---
+
+The bare minimum to get started with TanStack Form is to create a form and add a field. Keep in mind that this example does not include any validation or error handling... yet.
+
+```vue
+<!-- App.vue -->
+<script setup>
+import { useForm } from '@tanstack/vue-form'
+
+const form = useForm({
+  // Memoize your default values to prevent re-renders
+  defaultValues: {
+    fullName: '',
+  },
+  onSubmit: async (values) => {
+    // Do something with form data
+    console.log(values)
+  },
+})
+
+form.provideFormContext()
+</script>
+
+<template>
+  <div>
+    <div>
+      <form.Field name="fullName">
+        <template v-slot="field">
+          <input
+            :name="field.name"
+            :value="field.state.value"
+            :onBlur="field.handleBlur"
+            :onChange="(e) => field.handleChange(e.target.value)"
+          />
+        </template>
+      </form.Field>
+    </div>
+    <button type="submit">Submit</button>
+  </div>
+</template>
+```
+
+From here, you'll be ready to explore all of the other features of TanStack Form!

docs/framework/vue/reference/Field.md

@@ -0,0 +1,6 @@
+---
+id: field
+title: Field
+---
+
+Please see [/packages/vue-form/src/useField.tsx](https://github.com/TanStack/form/blob/main/packages/vue-form/src/useField.tsx)

docs/framework/vue/reference/createFormFactory.md

@@ -0,0 +1,36 @@
+---
+id: createFormFactory
+title: createFormFactory
+---
+
+### `createFormFactory`
+
+```tsx
+export function createFormFactory<TFormData>(
+  opts?: FormOptions<TFormData>,
+): FormFactory<TFormData>
+```
+
+A function that creates a new `FormFactory<TFormData>` instance.
+
+- `opts`
+  - Optional form options and a `listen` function to be called with the form state.
+
+### `FormFactory<TFormData>`
+
+A type representing a form factory. Form factories provide a type-safe way to interact with the form API as opposed to using the globally exported form utilities.
+
+```tsx
+export type FormFactory<TFormData> = {
+  useForm: (opts?: FormOptions<TFormData>) => FormApi<TFormData>
+  useField: UseField<TFormData>
+  Field: FieldComponent<TFormData>
+}
+```
+
+- `useForm`
+  - A custom composition that creates and returns a new instance of the `FormApi<TFormData>` class.
+- `useField`
+  - A custom composition that returns an instance of the `FieldApi<TFormData>` class.
+- `Field`
+  - A form field component.

docs/framework/vue/reference/fieldApi.md

@@ -0,0 +1,6 @@
+---
+id: fieldApi
+title: Field API
+---
+
+Please see [/packages/vue-form/src/useField.tsx](https://github.com/TanStack/form/blob/main/packages/vue-form/src/useField.tsx)

docs/framework/vue/reference/formApi.md

@@ -0,0 +1,6 @@
+---
+id: formApi
+title: Form API
+---
+
+Please see [/packages/vue-form/src/useForm.tsx](https://github.com/TanStack/form/blob/main/packages/vue-form/src/useForm.tsx)

docs/framework/vue/reference/useField.md

@@ -0,0 +1,6 @@
+---
+id: useField
+title: useField
+---
+
+Please see [/packages/vue-form/src/useField.tsx](https://github.com/TanStack/form/blob/main/packages/vue-form/src/useField.tsx)

docs/framework/vue/reference/useForm.md

@@ -0,0 +1,6 @@
+---
+id: useForm
+title: useForm
+---
+
+Please see [/packages/vue-form/src/useForm.tsx](https://github.com/TanStack/form/blob/main/packages/vue-form/src/useForm.tsx)

examples/vue/simple/.gitignore

@@ -0,0 +1,9 @@
+node_modules
+.DS_Store
+dist
+dist-ssr
+*.local
+
+package-lock.json
+yarn.lock
+pnpm-lock.yaml

examples/vue/simple/README.md

@@ -0,0 +1,6 @@
+# Basic example
+
+To run this example:
+
+- `npm install` or `yarn` or `pnpm i`
+- `npm run dev` or `yarn dev` or `pnpm dev`

examples/vue/simple/index.html

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Vue Form Example</title>
+  </head>
+  <body>
+    <div id="app"></div>
+    <script type="module" src="/src/main.ts"></script>
+  </body>
+</html>

examples/vue/simple/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "@tanstack/form-example-vue-simple",
+  "private": true,
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "build:dev": "vite build -m development",
+    "serve": "vite preview"
+  },
+  "dependencies": {
+    "@tanstack/vue-form": "workspace:*",
+    "vue": "^3.3.4"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-vue": "^4.2.3",
+    "typescript": "^5.0.4",
+    "vite": "^4.4.4"
+  }
+}

examples/vue/simple/src/App.vue

@@ -0,0 +1,83 @@
+<script setup lang="ts">
+import { useForm } from '@tanstack/vue-form'
+import FieldInfo from './FieldInfo.vue'
+import { provideFormContext } from '@tanstack/vue-form/src'
+
+const form = useForm({
+  defaultValues: {
+    firstName: '',
+    lastName: '',
+  },
+  onSubmit: async (values) => {
+    // Do something with form data
+    alert(JSON.stringify(values))
+  },
+})
+
+form.provideFormContext()
+
+async function onChangeFirstName(value) {
+  await new Promise((resolve) => setTimeout(resolve, 1000))
+  return value.includes(`error`) && `No 'error' allowed in first name`
+}
+</script>
+
+<template>
+  <form
+    @submit="
+      (e) => {
+        e.preventDefault()
+        e.stopPropagation()
+        void form.handleSubmit()
+      }
+    "
+  >
+    <div>
+      <form.Field
+        name="firstName"
+        :onChange="
+          (value) =>
+            !value
+              ? `A first name is required`
+              : value.length < 3
+              ? `First name must be at least 3 characters`
+              : undefined
+        "
+        :onChangeAsyncDebounceMs="500"
+        :onChangeAsync="onChangeFirstName"
+      >
+        <template v-slot="field, state">
+          <label :htmlFor="field.name">First Name:</label>
+          <input
+            :name="field.name"
+            :value="field.state.value"
+            @input="(e) => field.handleChange(e.target.value)"
+            @blur="field.handleBlur"
+          />
+          <FieldInfo :state="state" />
+        </template>
+      </form.Field>
+    </div>
+    <div>
+      <form.Field name="lastName">
+        <template v-slot="field, state">
+          <label :htmlFor="field.name">Last Name:</label>
+          <input
+            :name="field.name"
+            :value="field.state.value"
+            @input="(e) => field.handleChange(e.target.value)"
+            @blur="field.handleBlur"
+          />
+          <FieldInfo :state="state" />
+        </template>
+      </form.Field>
+    </div>
+    <form.Subscribe>
+      <template v-slot="{ canSubmit, isSubmitting }">
+        <button type="submit" :disabled="!canSubmit">
+          {{ isSubmitting ? '...' : 'Submit' }}
+        </button>
+      </template>
+    </form.Subscribe>
+  </form>
+</template>

examples/vue/simple/src/FieldInfo.vue

@@ -0,0 +1,14 @@
+<script setup lang="ts">
+import { FieldApi } from '@tanstack/vue-form'
+
+const props = defineProps<{
+  state: FieldApi<any, any>['state']
+}>()
+</script>
+
+<template>
+  <em v-if="props.state.meta.touchedError">{{
+    props.state.meta.touchedError
+  }}</em>
+  {{ props.state.meta.isValidating ? 'Validating...' : null }}
+</template>

examples/vue/simple/src/main.ts

@@ -0,0 +1,5 @@
+import { createApp } from 'vue'
+
+import App from './App.vue'
+
+createApp(App).mount('#app')

examples/vue/simple/src/shims-vue.d.ts

@@ -0,0 +1,5 @@
+declare module '*.vue' {
+  import { DefineComponent } from 'vue'
+  const component: DefineComponent<{}, {}, any>
+  export default component
+}

examples/vue/simple/src/types.d.ts

@@ -0,0 +1,6 @@
+export interface Post {
+  userId: number
+  id: number
+  title: string
+  body: string
+}

examples/vue/simple/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "target": "esnext",
+    "module": "esnext",
+    "moduleResolution": "node",
+    "strict": true,
+    "jsx": "preserve",
+    "sourceMap": true,
+    "resolveJsonModule": true,
+    "esModuleInterop": true,
+    "lib": ["esnext", "dom"],
+    "types": ["vite/client"]
+  },
+  "include": ["src/**/*.ts", "src/**/*.d.ts", "src/**/*.vue"]
+}

examples/vue/simple/vite.config.ts

@@ -0,0 +1,10 @@
+import { defineConfig } from 'vite'
+import createVuePlugin from '@vitejs/plugin-vue'
+
+// https://vitejs.dev/config/
+export default defineConfig({
+  plugins: [createVuePlugin()],
+  optimizeDeps: {
+    exclude: ['@tanstack/vue-query', 'vue-demi'],
+  },
+})

package.json

@@ -44,6 +44,7 @@
     "@testing-library/react": "^14.0.0",
     "@testing-library/react-hooks": "^8.0.1",
     "@testing-library/user-event": "^14.4.3",
+    "@testing-library/vue": "^7.0.0",
     "@types/jest": "^26.0.4",
     "@types/luxon": "^2.3.1",
     "@types/node": "^17.0.25",
@@ -53,6 +54,8 @@
     "@types/testing-library__jest-dom": "^5.14.5",
     "@typescript-eslint/eslint-plugin": "^6.4.1",
     "@typescript-eslint/parser": "^6.4.1",
+    "@vitejs/plugin-vue": "^4.3.4",
+    "@vitejs/plugin-vue-jsx": "^3.0.2",
     "@vitest/coverage-istanbul": "^0.34.3",
     "axios": "^0.26.1",
     "babel-eslint": "^10.1.0",
@@ -84,6 +87,7 @@
     "react-dom-17": "npm:react-dom@^17.0.2",
     "rimraf": "^5.0.1",
     "rollup": "^3.23.0",
+    "rollup-plugin-esbuild": "^5.0.0",
     "rollup-plugin-node-externals": "^6.1.0",
     "rollup-plugin-preserve-directives": "^0.2.0",
     "rollup-plugin-size": "^0.2.2",
@@ -97,7 +101,7 @@
     "type-fest": "^3.11.0",
     "typescript": "^5.2.2",
     "vitest": "^0.34.3",
-    "vue": "^3.2.47"
+    "vue": "^3.3.4"
   },
   "bundlewatch": {
     "files": [

packages/vue-form/.eslintrc.cjs

@@ -0,0 +1,11 @@
+// @ts-check
+
+/** @type {import('eslint').Linter.Config} */
+const config = {
+  parserOptions: {
+    tsconfigRootDir: __dirname,
+    project: './tsconfig.json',
+  },
+}
+
+module.exports = config

packages/vue-form/README.md

@@ -0,0 +1,35 @@
+<img src="https://static.scarf.sh/a.png?x-pxid=be2d8a11-9712-4c1d-9963-580b2d4fb133" />
+
+![TanStack Form Header](https://github.com/TanStack/form/raw/main/media/repo-header.png)
+
+Hooks for managing form state in Vue
+
+<a href="https://twitter.com/intent/tweet?button_hashtag=TanStack" target="\_parent">
+  <img alt="#TanStack" src="https://img.shields.io/twitter/url?color=%2308a0e9&label=%23TanStack&style=social&url=https%3A%2F%2Ftwitter.com%2Fintent%2Ftweet%3Fbutton_hashtag%3DTanStack">
+</a><a href="https://discord.com/invite/WrRKjPJ" target="\_parent">
+  <img alt="" src="https://img.shields.io/badge/Discord-TanStack-%235865F2" />
+</a><a href="https://github.com/TanStack/form/actions?query=workflow%3A%22vue-form+tests%22">
+<img src="https://github.com/TanStack/form/workflows/vue-form%20tests/badge.svg" />
+</a><a href="https://www.npmjs.com/package/@tanstack/form-core" target="\_parent">
+  <img alt="" src="https://img.shields.io/npm/dm/@tanstack/form-core.svg" />
+</a><a href="https://bundlephobia.com/package/@tanstack/vue-form@latest" target="\_parent">
+  <img alt="" src="https://badgen.net/bundlephobia/minzip/@tanstack/vue-form" />
+</a><a href="#badge">
+    <img alt="semantic-release" src="https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg">
+  </a><a href="https://github.com/TanStack/form/discussions">
+  <img alt="Join the discussion on Github" src="https://img.shields.io/badge/Github%20Discussions%20%26%20Support-Chat%20now!-blue" />
+</a><a href="https://bestofjs.org/projects/tanstack-form"><img alt="Best of JS" src="https://img.shields.io/endpoint?url=https://bestofjs-serverless.now.sh/api/project-badge?fullName=TanStack%form%26since=daily" /></a><a href="https://github.com/TanStack/form/" target="\_parent">
+  <img alt="" src="https://img.shields.io/github/stars/TanStack/form.svg?style=social&label=Star" />
+</a><a href="https://twitter.com/tannerlinsley" target="\_parent">
+  <img alt="" src="https://img.shields.io/twitter/follow/tannerlinsley.svg?style=social&label=Follow" />
+</a> <a href="https://gitpod.io/from-referrer/">
+  <img src="https://img.shields.io/badge/Gitpod-Ready--to--Code-blue?logo=gitpod" alt="Gitpod Ready-to-Code"/>
+</a>
+
+Enjoy this library? Try the entire [TanStack](https://tanstack.com)! [TanStack Table](https://github.com/TanStack/table), [TanStack Router](https://github.com/tanstack/router), [TanStack Virtual](https://github.com/tanstack/virtual), [React Charts](https://github.com/TanStack/react-charts), [React Ranger](https://github.com/TanStack/ranger)
+
+## Visit [tanstack.com/form](https://tanstack.com/form) for docs, guides, API and more!
+
+### [Become a Sponsor!](https://github.com/sponsors/tannerlinsley/)
+
+<!-- Use the force, Luke -->

packages/vue-form/package.json

@@ -0,0 +1,68 @@
+{
+  "name": "@tanstack/vue-form",
+  "version": "0.0.12",
+  "description": "Powerful, type-safe forms for Vue.",
+  "author": "tannerlinsley",
+  "license": "MIT",
+  "repository": "tanstack/form",
+  "homepage": "https://tanstack.com/form",
+  "funding": {
+    "type": "github",
+    "url": "https://github.com/sponsors/tannerlinsley"
+  },
+  "type": "module",
+  "types": "build/lib/index.d.ts",
+  "main": "build/lib/index.legacy.cjs",
+  "module": "build/lib/index.legacy.js",
+  "exports": {
+    ".": {
+      "types": "./build/lib/index.d.ts",
+      "import": "./build/lib/index.js",
+      "require": "./build/lib/index.cjs",
+      "default": "./build/lib/index.cjs"
+    },
+    "./package.json": "./package.json"
+  },
+  "sideEffects": false,
+  "scripts": {
+    "clean": "rimraf ./build && rimraf ./coverage",
+    "test:eslint": "eslint --ext .ts,.tsx ./src",
+    "test:types": "tsc",
+    "fixme:test:lib": "pnpm run test:2 && pnpm run test:2.7 && pnpm run test:3",
+    "test:lib": "pnpm run test:3",
+    "test:2": "vue-demi-switch 2 vue2 && vitest",
+    "test:2.7": "vue-demi-switch 2.7 vue2.7 && vitest",
+    "test:3": "vue-demi-switch 3 && vitest",
+    "test:lib:dev": "pnpm run test:lib --watch",
+    "test:build": "publint --strict",
+    "build": "pnpm build:rollup && pnpm build:codemods && pnpm build:types",
+    "build:rollup": "rollup --config rollup.config.js",
+    "build:codemods": "cpy ../codemods/src/**/* ./build/codemods",
+    "build:types": "tsc --emitDeclarationOnly"
+  },
+  "files": [
+    "build",
+    "src"
+  ],
+  "dependencies": {
+    "@tanstack/form-core": "workspace:*",
+    "@tanstack/store": "0.1.3",
+    "@tanstack/vue-store": "0.1.3",
+    "vue-demi": "^0.14.6"
+  },
+  "devDependencies": {
+    "@vue/composition-api": "1.7.2",
+    "vue": "^3.3.4",
+    "vue2": "npm:vue@2.6",
+    "vue2.7": "npm:vue@2.7"
+  },
+  "peerDependencies": {
+    "@vue/composition-api": "^1.1.2",
+    "vue": "^2.5.0 || ^3.0.0"
+  },
+  "peerDependenciesMeta": {
+    "@vue/composition-api": {
+      "optional": true
+    }
+  }
+}

packages/vue-form/rollup.config.js

@@ -0,0 +1,12 @@
+// @ts-check
+
+import { defineConfig } from 'rollup'
+import { buildConfigs } from '../../scripts/getRollupConfig.js'
+
+export default defineConfig(
+  buildConfigs({
+    name: 'vue-form',
+    outputFile: 'index',
+    entryFile: './src/index.ts',
+  }),
+)

packages/vue-form/src/createFormFactory.ts

@@ -0,0 +1,23 @@
+import type { FormApi, FormOptions } from '@tanstack/form-core'
+
+import { type UseField, type FieldComponent, Field, useField } from './useField'
+import { useForm } from './useForm'
+
+export type FormFactory<TFormData> = {
+  useForm: (opts?: FormOptions<TFormData>) => FormApi<TFormData>
+  useField: UseField<TFormData>
+  Field: FieldComponent<TFormData, TFormData>
+}
+
+export function createFormFactory<TFormData>(
+  defaultOpts?: FormOptions<TFormData>,
+): FormFactory<TFormData> {
+  return {
+    useForm: (opts) => {
+      const formOptions = Object.assign({}, defaultOpts, opts)
+      return useForm<TFormData>(formOptions)
+    },
+    useField: useField as any,
+    Field: Field as any,
+  }
+}

packages/vue-form/src/formContext.ts

@@ -0,0 +1,23 @@
+import type { FormApi } from '@tanstack/form-core'
+import { inject, provide } from 'vue-demi'
+
+export type FormContext = {
+  formApi: FormApi<any>
+  parentFieldName?: string
+} | null
+
+export const formContext = Symbol('FormContext')
+
+export function provideFormContext(val: FormContext) {
+  provide(formContext, val)
+}
+
+export function useFormContext() {
+  const formApi = inject(formContext) as FormContext
+
+  if (!formApi) {
+    throw new Error(`You are trying to use the form API outside of a form!`)
+  }
+
+  return formApi
+}

packages/vue-form/src/index.ts

@@ -0,0 +1,5 @@
+export * from '@tanstack/form-core'
+export * from './createFormFactory'
+export * from './formContext'
+export * from './useField'
+export * from './useForm'

packages/vue-form/src/sfc.d.ts

@@ -0,0 +1 @@
+declare module '*.vue'

packages/vue-form/src/tests/useField.test.tsx

@@ -0,0 +1,240 @@
+/// <reference lib="dom" />
+import { h, defineComponent } from 'vue-demi'
+import { render, waitFor } from '@testing-library/vue'
+import '@testing-library/jest-dom'
+import {
+  createFormFactory,
+  type FieldApi,
+  provideFormContext,
+  useForm,
+} from '../index'
+import userEvent from '@testing-library/user-event'
+import * as React from 'react'
+import { sleep } from './utils'
+
+const user = userEvent.setup()
+
+describe('useField', () => {
+  it('should allow to set default value', async () => {
+    type Person = {
+      firstName: string
+      lastName: string
+    }
+
+    const formFactory = createFormFactory<Person>()
+
+    const Comp = defineComponent(() => {
+      const form = formFactory.useForm()
+
+      provideFormContext({ formApi: form })
+
+      return () => (
+        <form.Field name="firstName" defaultValue="FirstName">
+          {(field: FieldApi<string, Person>) => (
+            <input
+              data-testid={'fieldinput'}
+              value={field.state.value}
+              onBlur={field.handleBlur}
+              onInput={(e) =>
+                field.handleChange((e.target as HTMLInputElement).value)
+              }
+            />
+          )}
+        </form.Field>
+      )
+    })
+
+    const { getByTestId } = render(Comp)
+    const input = getByTestId('fieldinput')
+    await waitFor(() => expect(input).toHaveValue('FirstName'))
+  })
+
+  it('should not validate on change if isTouched is false', async () => {
+    type Person = {
+      firstName: string
+      lastName: string
+    }
+    const error = 'Please enter a different value'
+
+    const formFactory = createFormFactory<Person>()
+
+    const Comp = defineComponent(() => {
+      const form = formFactory.useForm()
+
+      provideFormContext({ formApi: form })
+
+      return () => (
+        <form.Field
+          name="firstName"
+          onChange={(value) => (value === 'other' ? error : undefined)}
+        >
+          {(field: FieldApi<string, Person>) => (
+            <div>
+              <input
+                data-testid="fieldinput"
+                name={field.name}
+                value={field.state.value}
+                onBlur={field.handleBlur}
+                onInput={(e) =>
+                  field.setValue((e.target as HTMLInputElement).value)
+                }
+              />
+              <p>{field.getMeta().error}</p>
+            </div>
+          )}
+        </form.Field>
+      )
+    })
+
+    const { getByTestId, queryByText } = render(Comp)
+    const input = getByTestId('fieldinput')
+    await user.type(input, 'other')
+    expect(queryByText(error)).not.toBeInTheDocument()
+  })
+
+  it('should validate on change if isTouched is true', async () => {
+    type Person = {
+      firstName: string
+      lastName: string
+    }
+    const error = 'Please enter a different value'
+
+    const formFactory = createFormFactory<Person>()
+
+    const Comp = defineComponent(() => {
+      const form = formFactory.useForm()
+
+      provideFormContext({ formApi: form })
+
+      return () => (
+        <form.Field
+          name="firstName"
+          onChange={(value) => (value === 'other' ? error : undefined)}
+        >
+          {(field: FieldApi<string, Person>) => (
+            <div>
+              <input
+                data-testid="fieldinput"
+                name={field.name}
+                value={field.state.value}
+                onBlur={field.handleBlur}
+                onInput={(e) =>
+                  field.handleChange((e.target as HTMLInputElement).value)
+                }
+              />
+              <p>{field.getMeta().error}</p>
+            </div>
+          )}
+        </form.Field>
+      )
+    })
+
+    const { getByTestId, getByText, queryByText } = render(Comp)
+    const input = getByTestId('fieldinput')
+    expect(queryByText(error)).not.toBeInTheDocument()
+    await user.type(input, 'other')
+    expect(getByText(error)).toBeInTheDocument()
+  })
+
+  it('should validate async on change', async () => {
+    type Person = {
+      firstName: string
+      lastName: string
+    }
+    const error = 'Please enter a different value'
+
+    const formFactory = createFormFactory<Person>()
+
+    const Comp = defineComponent(() => {
+      const form = formFactory.useForm()
+
+      provideFormContext({ formApi: form })
+
+      return () => (
+        <form.Field
+          name="firstName"
+          defaultMeta={{ isTouched: true }}
+          onChangeAsync={async () => {
+            await sleep(10)
+            return error
+          }}
+        >
+          {(field: FieldApi<string, Person>) => (
+            <div>
+              <input
+                data-testid="fieldinput"
+                name={field.name}
+                value={field.state.value}
+                onBlur={field.handleBlur}
+                onInput={(e) =>
+                  field.handleChange((e.target as HTMLInputElement).value)
+                }
+              />
+              <p>{field.getMeta().error}</p>
+            </div>
+          )}
+        </form.Field>
+      )
+    })
+
+    const { getByTestId, getByText, queryByText } = render(Comp)
+    const input = getByTestId('fieldinput')
+    expect(queryByText(error)).not.toBeInTheDocument()
+    await user.type(input, 'other')
+    await waitFor(() => getByText(error))
+    expect(getByText(error)).toBeInTheDocument()
+  })
+
+  it('should validate async on change with debounce', async () => {
+    type Person = {
+      firstName: string
+      lastName: string
+    }
+
+    const mockFn = vi.fn()
+    const error = 'Please enter a different value'
+    const formFactory = createFormFactory<Person>()
+
+    const Comp = defineComponent(() => {
+      const form = formFactory.useForm()
+
+      provideFormContext({ formApi: form })
+
+      return () => (
+        <form.Field
+          name="firstName"
+          defaultMeta={{ isTouched: true }}
+          onChangeAsyncDebounceMs={100}
+          onChangeAsync={async () => {
+            mockFn()
+            await sleep(10)
+            return error
+          }}
+        >
+          {(field: FieldApi<string, Person>) => (
+            <div>
+              <input
+                data-testid="fieldinput"
+                name={field.name}
+                value={field.state.value}
+                onBlur={field.handleBlur}
+                onInput={(e) =>
+                  field.handleChange((e.target as HTMLInputElement).value)
+                }
+              />
+              <p>{field.getMeta().error}</p>
+            </div>
+          )}
+        </form.Field>
+      )
+    })
+
+    const { getByTestId, getByText } = render(<Comp />)
+    const input = getByTestId('fieldinput')
+    await user.type(input, 'other')
+    // mockFn will have been called 5 times without onChangeAsyncDebounceMs
+    expect(mockFn).toHaveBeenCalledTimes(0)
+    await waitFor(() => getByText(error))
+    expect(getByText(error)).toBeInTheDocument()
+  })
+})

packages/vue-form/src/tests/useForm.test.tsx

@@ -0,0 +1,130 @@
+/// <reference lib="dom" />
+import { h, defineComponent, ref } from 'vue-demi'
+import { render } from '@testing-library/vue'
+import '@testing-library/jest-dom'
+import {
+  createFormFactory,
+  type FieldApi,
+  provideFormContext,
+  useForm,
+} from '../index'
+import userEvent from '@testing-library/user-event'
+import * as React from 'react'
+import { waitFor } from '@testing-library/react'
+
+const user = userEvent.setup()
+
+describe('useForm', () => {
+  it('preserved field state', async () => {
+    type Person = {
+      firstName: string
+      lastName: string
+    }
+
+    const formFactory = createFormFactory<Person>()
+
+    const Comp = defineComponent(() => {
+      const form = formFactory.useForm()
+
+      provideFormContext({ formApi: form })
+
+      return () => (
+        <form.Field name="firstName" defaultValue="">
+          {(field: FieldApi<string, Person>) => (
+            <input
+              data-testid={'fieldinput'}
+              value={field.state.value}
+              onBlur={field.handleBlur}
+              onInput={(e) =>
+                field.handleChange((e.target as HTMLInputElement).value)
+              }
+            />
+          )}
+        </form.Field>
+      )
+    })
+
+    const { getByTestId, queryByText } = render(Comp)
+    const input = getByTestId('fieldinput')
+    expect(queryByText('FirstName')).not.toBeInTheDocument()
+    await user.type(input, 'FirstName')
+    expect(input).toHaveValue('FirstName')
+  })
+
+  it('should allow default values to be set', async () => {
+    type Person = {
+      firstName: string
+      lastName: string
+    }
+
+    const formFactory = createFormFactory<Person>()
+
+    const Comp = defineComponent(() => {
+      const form = formFactory.useForm({
+        defaultValues: {
+          firstName: 'FirstName',
+          lastName: 'LastName',
+        },
+      })
+      form.provideFormContext()
+
+      return () => (
+        <form.Field name="firstName" defaultValue="">
+          {(field: FieldApi<string, Person>) => <p>{field.state.value}</p>}
+        </form.Field>
+      )
+    })
+
+    const { findByText, queryByText } = render(Comp)
+    expect(await findByText('FirstName')).toBeInTheDocument()
+    expect(queryByText('LastName')).not.toBeInTheDocument()
+  })
+
+  it('should handle submitting properly', async () => {
+    const Comp = defineComponent(() => {
+      const submittedData = ref<{ firstName: string }>()
+
+      const form = useForm({
+        defaultValues: {
+          firstName: 'FirstName',
+        },
+        onSubmit: (data) => {
+          submittedData.value = data
+        },
+      })
+      form.provideFormContext()
+
+      return () => (
+        <form.Provider>
+          <form.Field name="firstName">
+            {(field: FieldApi<string, { firstName: string }>) => {
+              return (
+                <input
+                  value={field.state.value}
+                  onBlur={field.handleBlur}
+                  onChange={(e) =>
+                    field.handleChange((e.target as HTMLInputElement).value)
+                  }
+                  placeholder={'First name'}
+                />
+              )
+            }}
+          </form.Field>
+          <button onClick={form.handleSubmit}>Submit</button>
+          {submittedData.value && (
+            <p>Submitted data: {submittedData.value.firstName}</p>
+          )}
+        </form.Provider>
+      )
+    })
+
+    const { findByPlaceholderText, getByText } = render(Comp)
+    const input = await findByPlaceholderText('First name')
+    await user.clear(input)
+    await user.type(input, 'OtherName')
+    await user.click(getByText('Submit'))
+    await waitFor(() =>
+      expect(getByText('Submitted data: OtherName')).toBeInTheDocument(),
+    )
+  })
+})

packages/vue-form/src/tests/utils.ts

@@ -0,0 +1,5 @@
+export function sleep(timeout: number): Promise<void> {
+  return new Promise((resolve, _reject) => {
+    setTimeout(resolve, timeout)
+  })
+}

packages/vue-form/src/types.ts

@@ -0,0 +1 @@
+export type NoInfer<T> = [T][T extends any ? 0 : never]

packages/vue-form/src/useField.tsx

@@ -0,0 +1,151 @@
+import {
+  type DeepKeys,
+  type DeepValue,
+  FieldApi,
+  type FieldOptions,
+  type Narrow,
+} from '@tanstack/form-core'
+import { useStore } from '@tanstack/vue-store'
+import {
+  type SetupContext,
+  defineComponent,
+  type Ref,
+  onMounted,
+  onUnmounted,
+  watch,
+} from 'vue-demi'
+import { provideFormContext, useFormContext } from './formContext'
+
+declare module '@tanstack/form-core' {
+  // eslint-disable-next-line no-shadow
+  interface FieldApi<TData, TFormData> {
+    Field: FieldComponent<TData, TFormData>
+  }
+}
+
+export interface UseFieldOptions<TData, TFormData>
+  extends FieldOptions<TData, TFormData> {
+  mode?: 'value' | 'array'
+}
+
+export type UseField<TFormData> = <TField extends DeepKeys<TFormData>>(
+  opts?: { name: Narrow<TField> } & UseFieldOptions<
+    DeepValue<TFormData, TField>,
+    TFormData
+  >,
+) => FieldApi<DeepValue<TFormData, TField>, TFormData>
+
+export function useField<TData, TFormData>(
+  opts: UseFieldOptions<TData, TFormData>,
+): {
+  api: FieldApi<TData, TFormData>
+  state: Readonly<Ref<FieldApi<TData, TFormData>['state']>>
+} {
+  // Get the form API either manually or from context
+  const { formApi, parentFieldName } = useFormContext()
+
+  const fieldApi = (() => {
+    const name = (
+      typeof opts.index === 'number'
+        ? [parentFieldName, opts.index, opts.name]
+        : [parentFieldName, opts.name]
+    )
+      .filter((d) => d !== undefined)
+      .join('.')
+
+    const api = new FieldApi({ ...opts, form: formApi, name: name as never })
+
+    api.Field = Field as never
+
+    return api
+  })()
+
+  const fieldState = useStore(fieldApi.store, (state) => state)
+
+  let cleanup!: () => void
+  onMounted(() => {
+    cleanup = fieldApi.mount()
+  })
+
+  onUnmounted(() => {
+    cleanup()
+  })
+
+  watch(
+    () => opts,
+    () => {
+      // Keep options up to date as they are rendered
+      fieldApi.update({ ...opts, form: formApi } as never)
+    },
+  )
+
+  return { api: fieldApi, state: fieldState } as never
+}
+
+// export type FieldValue<TFormData, TField> = TFormData extends any[]
+//   ? TField extends `[${infer TIndex extends number | 'i'}].${infer TRest}`
+//     ? DeepValue<TFormData[TIndex extends 'i' ? number : TIndex], TRest>
+//     : TField extends `[${infer TIndex extends number | 'i'}]`
+//     ? TFormData[TIndex extends 'i' ? number : TIndex]
+//     : never
+//   : TField extends `${infer TPrefix}[${infer TIndex extends
+//       | number
+//       | 'i'}].${infer TRest}`
+//   ? DeepValue<
+//       DeepValue<TFormData, TPrefix>[TIndex extends 'i' ? number : TIndex],
+//       TRest
+//     >
+//   : TField extends `${infer TPrefix}[${infer TIndex extends number | 'i'}]`
+//   ? DeepValue<TFormData, TPrefix>[TIndex extends 'i' ? number : TIndex]
+//   : DeepValue<TFormData, TField>
+
+export type FieldValue<TFormData, TField> = TFormData extends any[]
+  ? unknown extends TField
+    ? TFormData[number]
+    : DeepValue<TFormData[number], TField>
+  : DeepValue<TFormData, TField>
+
+// type Test1 = FieldValue<{ foo: { bar: string }[] }, 'foo'>
+// //   ^?
+// type Test2 = FieldValue<{ foo: { bar: string }[] }, 'foo[i]'>
+// //   ^?
+// type Test3 = FieldValue<{ foo: { bar: string }[] }, 'foo[2].bar'>
+// //   ^?
+
+export type FieldComponent<TParentData, TFormData> = <TField>(
+  fieldOptions: {
+    children?: (
+      fieldApi: FieldApi<FieldValue<TParentData, TField>, TFormData>,
+    ) => any
+  } & Omit<
+    UseFieldOptions<FieldValue<TParentData, TField>, TFormData>,
+    'name' | 'index'
+  > &
+    (TParentData extends any[]
+      ? {
+          name?: TField extends undefined ? TField : DeepKeys<TParentData>
+          index: number
+        }
+      : {
+          name: TField extends undefined ? TField : DeepKeys<TParentData>
+          index?: never
+        }),
+  context: SetupContext,
+) => any
+
+export const Field = defineComponent(
+  <TData, TFormData>(
+    fieldOptions: UseFieldOptions<TData, TFormData>,
+    context: SetupContext,
+  ) => {
+    const fieldApi = useField({ ...fieldOptions, ...context.attrs })
+
+    provideFormContext({
+      formApi: fieldApi.api.form,
+      parentFieldName: fieldApi.api.name,
+    } as never)
+
+    return () => context.slots.default!(fieldApi.api, fieldApi.state.value)
+  },
+  { name: 'Field', inheritAttrs: false },
+)

packages/vue-form/src/useForm.tsx

@@ -0,0 +1,63 @@
+import { FormApi, type FormState, type FormOptions } from '@tanstack/form-core'
+import { useStore } from '@tanstack/vue-store'
+import { type UseField, type FieldComponent, Field, useField } from './useField'
+import { provideFormContext } from './formContext'
+import { defineComponent } from 'vue-demi'
+import type { NoInfer } from './types'
+
+declare module '@tanstack/form-core' {
+  // eslint-disable-next-line no-shadow
+  interface FormApi<TFormData> {
+    Provider: (props: Record<string, any> & {}) => any
+    provideFormContext: () => void
+    Field: FieldComponent<TFormData, TFormData>
+    useField: UseField<TFormData>
+    useStore: <TSelected = NoInfer<FormState<TFormData>>>(
+      selector?: (state: NoInfer<FormState<TFormData>>) => TSelected,
+    ) => TSelected
+    Subscribe: <TSelected = NoInfer<FormState<TFormData>>>(props: {
+      selector?: (state: NoInfer<FormState<TFormData>>) => TSelected
+    }) => any
+  }
+}
+
+export function useForm<TData>(opts?: FormOptions<TData>): FormApi<TData> {
+  const formApi = (() => {
+    const api = new FormApi<TData>(opts)
+
+    api.Provider = defineComponent(
+      (_, context) => {
+        provideFormContext({ formApi })
+        return () => context.slots.default!()
+      },
+      { name: 'Provider' },
+    )
+    api.provideFormContext = () => {
+      provideFormContext({ formApi })
+    }
+    api.Field = Field as never
+    api.useField = useField as never
+    api.useStore = (selector) => {
+      return useStore(api.store as never, selector as never) as never
+    }
+    api.Subscribe = defineComponent(
+      (props, context) => {
+        const allProps = { ...props, ...context.attrs }
+        const selector = allProps.selector ?? ((state) => state)
+        const data = useStore(api.store as never, selector as never)
+        return () => context.slots.default!(data.value)
+      },
+      {
+        name: 'Subscribe',
+        inheritAttrs: false,
+      },
+    )
+
+    return api
+  })()
+
+  // formApi.useStore((state) => state.isSubmitting)
+  formApi.update(opts)
+
+  return formApi as never
+}

packages/vue-form/test-setup.ts

@@ -0,0 +1,8 @@
+import Vue from 'vue2'
+Vue.config.productionTip = false
+Vue.config.devtools = false
+
+// Hide annoying console warnings for Vue2
+import Vue27 from 'vue2.7'
+Vue27.config.productionTip = false
+Vue27.config.devtools = false

packages/vue-form/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "types": ["vitest/globals", "vue/jsx"],
+    "outDir": "./build/lib",
+    "jsx": "preserve",
+    "jsxImportSource": "vue"
+  },
+  "include": ["src"]
+}

packages/vue-form/vitest.config.ts

@@ -0,0 +1,17 @@
+import { defineConfig } from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    name: 'vue-query',
+    dir: './src',
+    watch: false,
+    environment: 'jsdom',
+    globals: true,
+    setupFiles: ['test-setup.ts'],
+    coverage: { provider: 'istanbul' },
+  },
+  esbuild: {
+    jsxFactory: 'h',
+    jsxFragment: 'Fragment',
+  },
+})

scripts/getRollupConfig.js

@@ -9,6 +9,9 @@ import commonJS from '@rollup/plugin-commonjs'
 import externals from 'rollup-plugin-node-externals'
 import preserveDirectives from 'rollup-plugin-preserve-directives'
 import { rootDir } from './config.js'
+import vue from '@vitejs/plugin-vue'
+import vueJsx from '@vitejs/plugin-vue-jsx'
+import esbuild from 'rollup-plugin-esbuild'
 
 /** @param {'development' | 'production'} type */
 const forceEnvPlugin = (type) =>
@@ -106,7 +109,26 @@ function modernConfig(opts) {
     input: [opts.entryFile],
     output: forceBundle ? bundleOutput : normalOutput,
     plugins: [
+      vue({
+        isProduction: true,
+      }),
+      vueJsx({
+        exclude: [
+          './packages/solid-form/**',
+          './packages/svelte-form/**',
+          './packages/react-form/**',
+        ],
+      }),
       commonJS(),
+      esbuild({
+        exclude: [],
+        loaders: {
+          '.vue': 'ts',
+        },
+        define: {
+          'process.env.NODE_ENV': JSON.stringify('production'),
+        },
+      }),
       babelPlugin('modern'),
       nodeResolve({ extensions: ['.ts', '.tsx'] }),
       forceDevEnv ? forceEnvPlugin('development') : undefined,
@@ -181,7 +203,26 @@ function legacyConfig(opts) {
     input: [opts.entryFile],
     output: forceBundle ? bundleOutput : normalOutput,
     plugins: [
+      vue({
+        isProduction: true,
+      }),
+      vueJsx({
+        exclude: [
+          './packages/solid-form/**',
+          './packages/svelte-form/**',
+          './packages/react-form/**',
+        ],
+      }),
       commonJS(),
+      esbuild({
+        exclude: [],
+        loaders: {
+          '.vue': 'ts',
+        },
+        define: {
+          'process.env.NODE_ENV': JSON.stringify('production'),
+        },
+      }),
       babelPlugin('legacy'),
       nodeResolve({ extensions: ['.ts', '.tsx'] }),
       forceDevEnv ? forceEnvPlugin('development') : undefined,