perf(void): reuse unchanged source analysis during dev rescans

packages/void/src/pages/scan.ts

@@ -1,4 +1,4 @@
-import { existsSync, readFileSync } from 'node:fs';
+import { existsSync } from 'node:fs';
 import { join, dirname, basename, extname } from 'pathslash';
 import { glob } from 'tinyglobby';
 import { parseSync } from 'vite';
@@ -16,6 +16,7 @@ import {
   type AstProgram,
   type AstVariableDeclaration,
 } from '../shared/ast.ts';
+import { deriveFromSource } from '../shared/source-analysis-cache.ts';
 import { staticExportInitializers, staticLiteral } from '../shared/static-exports.ts';
 import { scriptBlocks } from './island-imports.ts';
 import { resolveNamedLayout } from './layout-resolution.ts';
@@ -222,7 +223,8 @@ export async function scanPages(root: string, options?: PageScanOptions): Promis
   const layouts: Array<LayoutDefinition> = [];
   const namedLayouts: Array<NamedLayoutDefinition> = [];
 
-  for (const file of files) {
+  // Glob traversal order can vary between identical scans. Keep layout inventories stable too.
+  for (const file of files.sort()) {
     const segments = file.split('/');
     // Skip files starting with _ in any segment (except _layouts/)
     if (segments.some((s) => s.startsWith('_') && s !== '_layouts')) {
@@ -298,8 +300,11 @@ export async function scanPages(root: string, options?: PageScanOptions): Promis
       const candidate = `${serverBase}.server.${serverExt}`;
       if (existsSync(join(pagesDir, candidate))) {
         serverPath = candidate;
-        const content = readFileSync(join(pagesDir, candidate), 'utf-8');
-        const metadata = detectPageServerMetadata(content, candidate);
+
+        const metadata = deriveFromSource(join(pagesDir, candidate), 'page-server', (source) =>
+          detectPageServerMetadata(source, candidate),
+        );
+
         methods.push(...metadata.methods);
         revalidate = metadata.revalidate;
         prerender = metadata.prerender;
@@ -331,13 +336,16 @@ export async function scanPages(root: string, options?: PageScanOptions): Promis
     // Extract frontmatter metadata and layout from .md files, or layout from component files
     let metadata: { title?: string; description?: string } | undefined;
     let layout: string | false | undefined;
+
     if (ext === '.md') {
-      const mdContent = readFileSync(join(pagesDir, file), 'utf-8');
-      metadata = extractFrontmatterMeta(mdContent);
-      layout = extractFrontmatterLayout(mdContent);
+      ({ metadata, layout } = deriveFromSource(join(pagesDir, file), 'page-markdown', (source) => ({
+        metadata: extractFrontmatterMeta(source),
+        layout: extractFrontmatterLayout(source),
+      })));
     } else {
-      const componentContent = readFileSync(join(pagesDir, file), 'utf-8');
-      layout = componentLayout(componentContent, file);
+      layout = deriveFromSource(join(pagesDir, file), 'page-layout', (source) =>
+        componentLayout(source, file),
+      );
     }
 
     pages.push({
@@ -354,7 +362,7 @@ export async function scanPages(root: string, options?: PageScanOptions): Promis
       ...rendering,
       hasGetPrerenderPaths,
       island,
-      metadata,
+      metadata: metadata ? { ...metadata } : undefined,
       layout,
     });
   }

packages/void/src/plugin-inference.ts

@@ -11,6 +11,7 @@ import {
   type RouteEnvironment,
 } from './router/parse-filename.ts';
 import { isWebSocketPatternFile } from './router/websocket.ts';
+import { deriveFromSource } from './shared/source-analysis-cache.ts';
 import { getSsrServerEntryPath } from './ssr/entry.ts';
 
 const SOURCE_GLOB = '**/*.{ts,tsx,mts,js,jsx,mjs,astro}';
@@ -168,8 +169,10 @@ export function inferProjectBindings(
         return;
       }
     }
-    const code = readFileSync(file, 'utf-8');
-    allBindings.push(inferBindingsFromFile(file, code));
+
+    allBindings.push(
+      deriveFromSource(file, 'bindings', (code) => inferBindingsFromFile(file, code)),
+    );
   };
 
   for (const dir of dirs) {