fix(changecache): Improve cache manifest validation and atomic file writes; add local settings and overrides

ts/mod_format/classes.changecache.ts

@@ -29,21 +29,67 @@ export class ChangeCache {
   }
   
   async getManifest(): Promise<ICacheManifest> {
+    const defaultManifest: ICacheManifest = {
+      version: this.cacheVersion,
+      lastFormat: 0,
+      files: []
+    };
+    
     const exists = await plugins.smartfile.fs.fileExists(this.manifestPath);
     if (!exists) {
-      return {
-        version: this.cacheVersion,
-        lastFormat: 0,
-        files: []
-      };
+      return defaultManifest;
     }
     
-    const content = plugins.smartfile.fs.toStringSync(this.manifestPath);
-    return JSON.parse(content);
+    try {
+      const content = plugins.smartfile.fs.toStringSync(this.manifestPath);
+      const manifest = JSON.parse(content);
+      
+      // Validate the manifest structure
+      if (this.isValidManifest(manifest)) {
+        return manifest;
+      } else {
+        console.warn('Invalid manifest structure, returning default manifest');
+        return defaultManifest;
+      }
+    } catch (error) {
+      console.warn(`Failed to read cache manifest: ${error.message}, returning default manifest`);
+      // Try to delete the corrupted file
+      try {
+        await plugins.smartfile.fs.remove(this.manifestPath);
+      } catch (removeError) {
+        // Ignore removal errors
+      }
+      return defaultManifest;
+    }
   }
   
   async saveManifest(manifest: ICacheManifest): Promise<void> {
-    await plugins.smartfile.memory.toFs(JSON.stringify(manifest, null, 2), this.manifestPath);
+    // Validate before saving
+    if (!this.isValidManifest(manifest)) {
+      throw new Error('Invalid manifest structure, cannot save');
+    }
+    
+    // Use atomic write: write to temp file, then move it
+    const tempPath = `${this.manifestPath}.tmp`;
+    
+    try {
+      // Write to temporary file
+      const jsonContent = JSON.stringify(manifest, null, 2);
+      await plugins.smartfile.memory.toFs(jsonContent, tempPath);
+      
+      // Move temp file to actual manifest (atomic-like operation)
+      // Since smartfile doesn't have rename, we copy and delete
+      await plugins.smartfile.fs.copy(tempPath, this.manifestPath);
+      await plugins.smartfile.fs.remove(tempPath);
+    } catch (error) {
+      // Clean up temp file if it exists
+      try {
+        await plugins.smartfile.fs.remove(tempPath);
+      } catch (removeError) {
+        // Ignore removal errors
+      }
+      throw error;
+    }
   }
   
   async hasFileChanged(filePath: string): Promise<boolean> {
@@ -95,7 +141,7 @@ export class ChangeCache {
       return; // Don't cache directories
     }
     
-    const content = await plugins.smartfile.fs.toStringSync(absolutePath);
+    const content = plugins.smartfile.fs.toStringSync(absolutePath);
     const checksum = this.calculateChecksum(content);
     
     // Update manifest
@@ -153,4 +199,31 @@ export class ChangeCache {
   private calculateChecksum(content: string | Buffer): string {
     return plugins.crypto.createHash('sha256').update(content).digest('hex');
   }
+  
+  private isValidManifest(manifest: any): manifest is ICacheManifest {
+    // Check if manifest has the required structure
+    if (!manifest || typeof manifest !== 'object') {
+      return false;
+    }
+    
+    // Check required fields
+    if (typeof manifest.version !== 'string' ||
+        typeof manifest.lastFormat !== 'number' ||
+        !Array.isArray(manifest.files)) {
+      return false;
+    }
+    
+    // Check each file entry
+    for (const file of manifest.files) {
+      if (!file || typeof file !== 'object' ||
+          typeof file.path !== 'string' ||
+          typeof file.checksum !== 'string' ||
+          typeof file.modified !== 'number' ||
+          typeof file.size !== 'number') {
+        return false;
+      }
+    }
+    
+    return true;
+  }
 }