perf(i18nSetup): optimize file reading to reduce I/O operations

Refactored preprocessLitegraph() to read each file only once instead of twice.
Previously files were read once to check for 'declare' keywords and again to
process them. Now files are read once and processed inline if they contain
'declare' keywords, improving performance.

browser_tests/i18nSetup.ts

@@ -13,63 +13,54 @@ const litegraphSrcDir = path.join(rootDir, 'src/lib/litegraph/src')
 
 const backupMap = new Map<string, string>()
 
-/**
- * Find all TypeScript files in litegraph that contain 'declare' keywords
- * perf: this fn reads about 90+ files and costs 70ms
- */
-async function findFilesWithDeclare(): Promise<string[]> {
+export async function preprocessLitegraph() {
+  console.log('Preprocessing litegraph files for i18n collection...')
+
   // Search for all .ts files in litegraph src directory
   const pattern = path.join(litegraphSrcDir, '**/*.ts')
   const files = await glob(pattern, {
     ignore: ['**/*.test.ts', '**/*.spec.ts', '**/node_modules/**']
   })
-  // Filter to only files that actually contain 'declare' keyword
-  const filesWithDeclare = await Promise.all(
+
+  let processedCount = 0
+
+  // Process files in parallel - read once and process if needed
+  await Promise.all(
     files.map(async (filePath) => {
       try {
-        const content = await fs.readFile(filePath, 'utf-8')
+        const originalContent = await fs.readFile(filePath, 'utf-8')
+
         // Check for class property declarations with 'declare' keyword
-        return /^\s*declare\s+/m.test(content) ? filePath : null
-      } catch (error) {
-        console.warn(`  ⚠ Could not read ${filePath}: ${error.message}`)
-        return null
+        if (!/^\s*declare\s+/m.test(originalContent)) {
+          return // Skip files without declare keywords
+        }
+
+        // Store original content in memory
+        backupMap.set(filePath, originalContent)
+
+        // Remove 'declare' keyword from class properties
+        const modifiedContent = originalContent.replace(
+          /^(\s*)declare\s+/gm,
+          '$1// @ts-ignore - removed declare for Playwright\n$1'
+        )
+
+        // Write modified content
+        await fs.writeFile(filePath, modifiedContent)
+        console.log(`  ✓ Processed ${path.relative(litegraphSrcDir, filePath)}`)
+        processedCount++
+      } catch (error: unknown) {
+        console.warn(
+          `  ⚠ Could not process ${filePath}: ${String((error as Error)?.message || error)}`
+        )
       }
     })
   )
 
-  return filesWithDeclare.filter((file): file is string => file !== null)
-}
-
-export async function preprocessLitegraph() {
-  console.log('Preprocessing litegraph files for i18n collection...')
-
-  const filesToProcess = await findFilesWithDeclare()
-
-  if (filesToProcess.length === 0) {
+  if (processedCount === 0) {
     console.log('  ℹ No files with declare keywords found')
-    return
+  } else {
+    console.log(`  Processed ${processedCount} files with declare keywords`)
   }
-
-  console.log(`  Found ${filesToProcess.length} files with declare keywords`)
-
-  await Promise.all(
-    filesToProcess.map(async (filePath) => {
-      const originalContent = await fs.readFile(filePath, 'utf-8')
-
-      // Store original content in memory
-      backupMap.set(filePath, originalContent)
-
-      // Remove 'declare' keyword from class properties
-      const modifiedContent = originalContent.replace(
-        /^(\s*)declare\s+/gm,
-        '$1// @ts-ignore - removed declare for Playwright\n$1'
-      )
-
-      // Write modified content
-      await fs.writeFile(filePath, modifiedContent)
-      console.log(`  ✓ Processed ${path.relative(litegraphSrcDir, filePath)}`)
-    })
-  )
 }
 
 export async function restoreLitegraph() {