[2.x] Refactor createInertiaApp in Svelte adapter (#2036)

* Refactor state management

* Move SSR logic to user-land

* Toggle "removeComments" TS option back to true

* Fix type error

packages/svelte/src/components/App.svelte

@@ -1,16 +1,52 @@
+<script context="module" lang="ts">
+  import type { ComponentResolver, ResolvedComponent } from '../types'
+  import { type Page } from '@inertiajs/core'
+
+  export interface InertiaAppProps {
+    initialComponent: ResolvedComponent
+    initialPage: Page
+    resolveComponent: ComponentResolver
+  }
+</script>
+
 <script lang="ts">
   import type { LayoutType, LayoutResolver } from '../types'
-  import type { PageProps } from '@inertiajs/core'
-  import type { RenderProps } from './Render.svelte'
-  import Render, { h } from './Render.svelte'
-  import store, { type InertiaStore } from '../store'
+  import { router, type PageProps } from '@inertiajs/core'
+  import Render, { h, type RenderProps } from './Render.svelte'
+  import { setPage } from '../page'
+
+  export let initialComponent: InertiaAppProps['initialComponent']
+  export let initialPage: InertiaAppProps['initialPage']
+  export let resolveComponent: InertiaAppProps['resolveComponent']
 
-  $: props = resolveProps($store)
+  let component = initialComponent
+  let key: number | null = null
+  let page = initialPage
+  let renderProps = resolveRenderProps(component, page, key)
+
+  setPage(page)
+
+  const isServer = typeof window === 'undefined'
+
+  if (!isServer) {
+    router.init({
+      initialPage,
+      resolveComponent,
+      swapComponent: async (args) => {
+        component = args.component as ResolvedComponent
+        page = args.page
+        key = args.preserveState ? key : Date.now()
+
+        renderProps = resolveRenderProps(component, page, key)
+        setPage(page)
+      },
+    })
+  }
 
   /**
    * Resolves the render props for the current page component, including layouts.
    */
-  function resolveProps({ component, page, key = null }: InertiaStore): RenderProps {
+  function resolveRenderProps(component: ResolvedComponent, page: Page, key: number | null = null): RenderProps {
     const child = h(component.default, page.props, [], key)
     const layout = component.layout
 
@@ -64,6 +100,4 @@
   }
 </script>
 
-{#if props}
-  <Render {...props} />
-{/if}
+<Render {...renderProps} />

packages/svelte/src/components/Render.svelte

@@ -7,7 +7,7 @@
     props?: PageProps
     children?: RenderProps[]
     key?: number | null
-  } | null
+  }
 
   export type RenderFunction = {
     (component: ComponentType, props?: PageProps, children?: RenderProps[], key?: number | null): RenderProps

packages/svelte/src/createInertiaApp.ts

@@ -1,25 +1,20 @@
 import { router, setupProgress, type InertiaAppResponse, type Page } from '@inertiajs/core'
 import escape from 'html-escape'
 import type { ComponentType } from 'svelte'
-import { version as SVELTE_VERSION } from 'svelte/package.json'
-import App from './components/App.svelte'
-import store from './store'
-import type { ComponentResolver, ResolvedComponent } from './types'
+import App, { type InertiaAppProps } from './components/App.svelte'
+import type { ComponentResolver } from './types'
 
 type SvelteRenderResult = { html: string; head: string; css?: { code: string } }
-type AppComponent = ComponentType<App> & { render: () => SvelteRenderResult }
+type AppComponent = ComponentType<App> & { render: (props: InertiaAppProps) => SvelteRenderResult }
 
 interface CreateInertiaAppProps {
   id?: string
   resolve: ComponentResolver
-  setup?: (props: {
-    el: HTMLElement
-    App: ComponentType<App>
-    props: {
-      initialPage: Page
-      resolveComponent: ComponentResolver
-    }
-  }) => void | App
+  setup: (props: {
+    el: HTMLElement | null
+    App: AppComponent
+    props: InertiaAppProps
+  }) => void | App | SvelteRenderResult
   progress?:
     | false
     | {
@@ -40,75 +35,32 @@ export default async function createInertiaApp({
 }: CreateInertiaAppProps): InertiaAppResponse {
   const isServer = typeof window === 'undefined'
   const el = isServer ? null : document.getElementById(id)
-  const initialPage: Page = page || JSON.parse(el?.dataset?.page || '{}')
+  const initialPage: Page = page || JSON.parse(el?.dataset.page || '{}')
   const resolveComponent = (name: string) => Promise.resolve(resolve(name))
 
-  await Promise.all([resolveComponent(initialPage.component), router.decryptHistory().catch(() => {})]).then(
-    ([initialComponent]) => {
-      store.set({
-        component: initialComponent,
-        page: initialPage,
-        key: null,
-      })
-    },
-  )
+  const [initialComponent] = await Promise.all([
+    resolveComponent(initialPage.component),
+    router.decryptHistory().catch(() => {}),
+  ])
 
-  if (isServer) {
-    const isSvelte5 = SVELTE_VERSION.startsWith('5')
-    const { html, head, css } = await (async () => {
-      if (isSvelte5) {
-        const { render } = await dynamicImport('svelte/server')
-        if (typeof render === 'function') {
-          return render(App) as SvelteRenderResult
-        }
-      }
+  const props: InertiaAppProps = { initialPage, initialComponent, resolveComponent }
 
-      return (App as AppComponent).render()
-    })()
+  const svelteApp = setup({
+    el,
+    App: App as unknown as AppComponent,
+    props
+  })
+
+  if (isServer) {
+    const { html, head, css } = svelteApp as SvelteRenderResult
 
     return {
       body: `<div data-server-rendered="true" id="${id}" data-page="${escape(JSON.stringify(initialPage))}">${html}</div>`,
       head: [head, css ? `<style data-vite-css>${css.code}</style>` : ''],
     }
   }
 
-  if (!el) {
-    throw new Error(`Element with ID "${id}" not found.`)
-  }
-
-  router.init({
-    initialPage,
-    resolveComponent,
-    swapComponent: async ({ component, page, preserveState }) => {
-      store.update((current) => ({
-        component: component as ResolvedComponent,
-        page,
-        key: preserveState ? current.key : Date.now(),
-      }))
-    },
-  })
-
   if (progress) {
     setupProgress(progress)
   }
-
-  setup({
-    el,
-    App,
-    props: {
-      initialPage,
-      resolveComponent,
-    },
-  })
-}
-
-// Loads the module dynamically during execution instead of at
-// build time. The `@vite-ignore` flag prevents Vite from
-// analyzing or pre-bundling this import.
-async function dynamicImport(module: string) {
-  try {
-    return await import(/* @vite-ignore */ module)
-  } catch {
-    return null
-  }
 }

packages/svelte/src/page.ts

@@ -1,6 +1,8 @@
-import { derived } from 'svelte/store'
-import store from './store'
+import { type Page } from '@inertiajs/core'
+import { writable } from 'svelte/store'
 
-const page = derived(store, ($store) => $store.page)
+const { set, subscribe } = writable<Page>()
 
-export default page
+export const setPage = set
+
+export default { subscribe }

packages/svelte/test-app/Pages/Svelte/PropsAndPageStore.svelte

@@ -0,0 +1,41 @@
+<script>
+  import { inertia, page, router, useForm } from '@inertiajs/svelte'
+  import { onMount } from 'svelte'
+
+  export let foo
+  
+  const form = useForm({ foo })
+
+  console.log('[script] foo prop is', foo)
+  console.log('[script] $page.props.foo is', $page.props.foo)
+
+  $: console.log('[reactive expression] foo prop is', foo)
+  $: console.log('[reactive expression] $page.props.foo is', $page.props.foo)
+
+  onMount(() => {
+    console.log('[onMount] foo prop is', foo)
+    console.log('[onMount] $page.props.foo is', $page.props.foo)
+  })
+</script>
+
+<div>
+  <input id="input" type="text" bind:value={$form.foo}>
+  <p>foo prop is {foo}</p>
+  <p>$page.props.foo is {$page.props.foo}</p>
+
+  <a
+    href="/svelte/props-and-page-store"
+    use:inertia={{ data: { foo: 'bar' } }}
+  >
+    Bar
+  </a>
+  <a
+    href="/svelte/props-and-page-store"
+    use:inertia={{ data: { foo: 'baz' } }}
+  >
+    Baz
+  </a>
+  <a href="/" use:inertia>
+    Home
+  </a>
+</div>

packages/svelte/test-app/app.ts

@@ -8,7 +8,7 @@ createInertiaApp({
     const pages = import.meta.glob<ResolvedComponent>('./Pages/**/*.svelte', { eager: true })
     return pages[`./Pages/${name}.svelte`]
   },
-  setup({ el, App }) {
-    new App({ target: el })
+  setup({ el, App, props }) {
+    new App({ target: el, props })
   },
 })

packages/svelte/tsconfig.json

@@ -20,6 +20,6 @@
     "noUnusedLocals": true,
     "noUnusedParameters": true,
     "preserveConstEnums": true,
-    "removeComments": false
+    "removeComments": true
   }
 }

playgrounds/svelte4/resources/js/app.ts

@@ -5,7 +5,7 @@ createInertiaApp({
     const pages = import.meta.glob<ResolvedComponent>('./Pages/**/*.svelte', { eager: true })
     return pages[`./Pages/${name}.svelte`]
   },
-  setup({ el, App }) {
-    new App({ target: el, hydrate: true })
+  setup({ el, App, props }) {
+    new App({ target: el, props, hydrate: true })
   },
 })

playgrounds/svelte4/resources/js/ssr.ts

@@ -8,5 +8,8 @@ createServer((page) =>
       const pages = import.meta.glob<ResolvedComponent>('./Pages/**/*.svelte', { eager: true })
       return pages[`./Pages/${name}.svelte`]
     },
+    setup({ App, props }) {
+      return App.render(props)
+    }
   }),
 )

playgrounds/svelte5/resources/js/app.ts

@@ -6,11 +6,11 @@ createInertiaApp({
     const pages = import.meta.glob<ResolvedComponent>('./Pages/**/*.svelte', { eager: true })
     return pages[`./Pages/${name}.svelte`]
   },
-  setup({ el, App }) {
+  setup({ el, App, props }) {
     if (el.dataset.serverRendered === 'true') {
-      hydrate(App, { target: el })
+      hydrate(App, { target: el, props })
     } else {
-      mount(App, { target: el })
+      mount(App, { target: el, props })
     }
   },
 })

playgrounds/svelte5/resources/js/ssr.ts

@@ -1,5 +1,6 @@
 import { createInertiaApp, type ResolvedComponent } from '@inertiajs/svelte'
 import createServer from '@inertiajs/svelte/server'
+import { render } from 'svelte/server'
 
 createServer((page) =>
   createInertiaApp({
@@ -8,5 +9,8 @@ createServer((page) =>
       const pages = import.meta.glob<ResolvedComponent>('./Pages/**/*.svelte', { eager: true })
       return pages[`./Pages/${name}.svelte`]
     },
+    setup({ App, props }) {
+      return render(App, { props })
+    }
   }),
 )

tests/app/server.js

@@ -310,6 +310,10 @@ app.get('/deferred-props/page-2', (req, res) => {
   }
 })
 
+app.get('/svelte/props-and-page-store', (req, res) =>
+  inertia.render(req, res, { component: 'Svelte/PropsAndPageStore', props: { foo: req.query.foo || 'default' }}),
+)
+
 app.all('/sleep', (req, res) => setTimeout(() => res.send(''), 2000))
 app.post('/redirect', (req, res) => res.redirect(303, '/dump/get'))
 app.get('/location', ({ res }) => inertia.location(res, '/dump/get'))