fix(solid-router): loaders being called twice during SSR

packages/solid-router/src/Transitioner.tsx

@@ -66,6 +66,7 @@ export function Transitioner() {
 
   // Try to load the initial location
   Solid.createRenderEffect(() => {
+    if (router.isServer) return
     Solid.untrack(() => {
       if (
         (typeof window !== 'undefined' && router.clientSsr) ||

packages/solid-router/tests/Transitioner.test.tsx

@@ -0,0 +1,70 @@
+import { describe, expect, it, vi } from 'vitest'
+import { render, waitFor } from '@solidjs/testing-library'
+import {
+  createMemoryHistory,
+  createRootRoute,
+  createRoute,
+  createRouter,
+} from '../src'
+import { RouterProvider } from '../src/RouterProvider'
+
+describe('Transitioner', () => {
+  it('should call router.load() when Transitioner mounts on the client', async () => {
+    const rootRoute = createRootRoute()
+    const indexRoute = createRoute({
+      getParentRoute: () => rootRoute,
+      path: '/',
+      component: () => <div>Index</div>,
+    })
+
+    const routeTree = rootRoute.addChildren([indexRoute])
+    const router = createRouter({
+      routeTree,
+      history: createMemoryHistory({
+        initialEntries: ['/'],
+      }),
+    })
+
+    // Mock router.load() to verify it gets called
+    const loadSpy = vi.spyOn(router, 'load').mockResolvedValue(undefined)
+
+    render(() => <RouterProvider router={router} />)
+
+    // Wait for the createRenderEffect to run and call router.load()
+    await waitFor(() => {
+      expect(loadSpy).toHaveBeenCalledTimes(1)
+    })
+
+    loadSpy.mockRestore()
+  })
+
+  it('should not call router.load() when on the server', async () => {
+    const rootRoute = createRootRoute()
+    const indexRoute = createRoute({
+      getParentRoute: () => rootRoute,
+      path: '/',
+      component: () => <div>Index</div>,
+    })
+
+    const routeTree = rootRoute.addChildren([indexRoute])
+    const router = createRouter({
+      routeTree,
+      history: createMemoryHistory({
+        initialEntries: ['/'],
+      }),
+      isServer: true,
+    })
+
+    // Mock router.load() to verify it gets called
+    const loadSpy = vi.spyOn(router, 'load').mockResolvedValue(undefined)
+
+    render(() => <RouterProvider router={router} />)
+
+    // Wait for the createRenderEffect to run and call router.load()
+    await waitFor(() => {
+      expect(loadSpy).toHaveBeenCalledTimes(0)
+    })
+
+    loadSpy.mockRestore()
+  })
+})

packages/solid-router/tests/router.test.tsx

@@ -1574,15 +1574,15 @@ describe('does not strip search params if search validation fails', () => {
     expect(window.location.search).toBe('?root=hello&index=world')
   })
 
-  it('root is missing', async () => {
+  it('root is missing', () => {
     window.history.replaceState(null, 'root', '/?index=world')
     const router = getRouter()
     render(() => <RouterProvider router={router} />)
 
     expect(window.location.search).toBe('?index=world')
   })
 
-  it('index is missing', async () => {
+  it('index is missing', () => {
     window.history.replaceState(null, 'root', '/?root=hello')
     const router = getRouter()