fix: tdz and host path normalization.

Author: knightedcodemonkey

playwright/app.spec.ts

@@ -376,6 +376,30 @@ test('react mode typecheck loads types without malformed URL fetches', async ({
   }
 })
 
+test('react mode executes default React import without TDZ runtime failure', async ({
+  page,
+}) => {
+  await waitForInitialRender(page)
+
+  await ensurePanelToolsVisible(page, 'component')
+
+  await page.getByLabel('ShadowRoot (open)').uncheck()
+  await page.locator('#render-mode').selectOption('react')
+  await setComponentEditorSource(
+    page,
+    [
+      "import React from 'react'",
+      'const App = () => <button>react default import works</button>',
+    ].join('\n'),
+  )
+
+  await expect(page.locator('#status')).toHaveText('Rendered')
+  await expect(page.locator('#preview-host button')).toContainText(
+    'react default import works',
+  )
+  await expect(page.locator('#preview-host pre')).toHaveCount(0)
+})
+
 test('clearing component source reports clear action without error status', async ({
   page,
 }) => {

src/modules/render-runtime.js

@@ -305,6 +305,17 @@ export const createRenderRuntimeController = ({
     const preamble = []
     const unsupportedSources = new Set()
     let requiresReactRuntime = false
+    let hasReactRuntimeAlias = false
+
+    const ensureReactRuntimeAlias = () => {
+      if (hasReactRuntimeAlias) {
+        return '__knightedReactRuntime'
+      }
+
+      hasReactRuntimeAlias = true
+      preamble.push('const __knightedReactRuntime = React')
+      return '__knightedReactRuntime'
+    }
 
     for (const entry of imports) {
       if (!entry || entry.importKind !== 'value') {
@@ -324,15 +335,28 @@ export const createRenderRuntimeController = ({
         }
 
         if (binding.kind === 'default' || binding.kind === 'namespace') {
+          if (binding.local === 'React') {
+            continue
+          }
+
           preamble.push(`const ${binding.local} = React`)
           continue
         }
 
         if (binding.kind === 'named') {
           if (binding.imported === 'default') {
+            if (binding.local === 'React') {
+              continue
+            }
+
             preamble.push(`const ${binding.local} = React`)
           } else {
-            preamble.push(`const ${binding.local} = React.${binding.imported}`)
+            if (binding.local === 'React') {
+              const reactRuntimeAlias = ensureReactRuntimeAlias()
+              preamble.push(`const React = ${reactRuntimeAlias}.${binding.imported}`)
+            } else {
+              preamble.push(`const ${binding.local} = React.${binding.imported}`)
+            }
           }
         }
       }

src/modules/type-diagnostics.js

@@ -681,11 +681,11 @@ export const createTypeDiagnosticsController = ({
       fileExists: fileName => files.has(normalizeVirtualFileName(fileName)),
       readFile: fileName => files.get(normalizeVirtualFileName(fileName)),
       directoryExists: directoryName => {
-        const normalized = normalizeRelativePath(directoryName)
+        const normalized = normalizeRelativePath(normalizeVirtualFileName(directoryName))
         return listVirtualDirectories(normalized).length > 0
       },
       getDirectories: directoryName => {
-        const normalized = normalizeRelativePath(directoryName)
+        const normalized = normalizeRelativePath(normalizeVirtualFileName(directoryName))
         return listVirtualDirectories(normalized)
       },
       realpath: fileName => normalizeVirtualFileName(fileName),