fix: improve ABL/DF WASM loading and handle FileSystemError gracefully

- Add multiple fallback strategies for loading ABL/DF WASM files
- Try loading from dist directory first, then npm packages
- Add better error handling for FileSystemError during file reads
- Handle canceled file operations gracefully in scanner

Author: roomote-agent

src/services/code-index/processors/scanner.ts

@@ -134,10 +134,21 @@ export class DirectoryScanner implements IDirectoryScanner {
 						return
 					}
 
-					// Read file content
-					const content = await vscode.workspace.fs
-						.readFile(vscode.Uri.file(filePath))
-						.then((buffer) => Buffer.from(buffer).toString("utf-8"))
+					// Read file content with better error handling
+					let content: string
+					try {
+						const buffer = await vscode.workspace.fs.readFile(vscode.Uri.file(filePath))
+						content = Buffer.from(buffer).toString("utf-8")
+					} catch (readError: any) {
+						// Handle FileSystemError specifically
+						if (readError?.name === "Canceled (FileSystemError)" || readError?.code === "Unknown") {
+							console.warn(`File read was canceled for ${filePath}, skipping file`)
+							skippedCount++
+							return
+						}
+						// Re-throw other errors
+						throw readError
+					}
 
 					// Calculate current hash
 					const currentFileHash = createHash("sha256").update(content).digest("hex")

src/services/tree-sitter/languageParser.ts

@@ -41,26 +41,57 @@ export interface LanguageParser {
 
 async function loadLanguage(langName: string, sourceDirectory?: string) {
 	const baseDir = sourceDirectory || __dirname
+	const { Language } = require("web-tree-sitter")
 
-	// Special handling for ABL and DF - load from node_modules
+	// Special handling for ABL and DF - try multiple loading strategies
 	if (langName === "abl" || langName === "df") {
+		// Strategy 1: Try to load from dist directory (where build process copies them)
 		try {
-			const { Language } = require("web-tree-sitter")
-			const packageName = `@usagi-coffee/tree-sitter-${langName}`
-			const wasmPath = require.resolve(`${packageName}/tree-sitter-${langName}.wasm`)
+			const wasmPath = path.join(baseDir, `tree-sitter-${langName}.wasm`)
 			return await Language.load(wasmPath)
-		} catch (error) {
-			console.error(
-				`Error loading ${langName} language from npm package: ${error instanceof Error ? error.message : error}`,
+		} catch (distError) {
+			console.warn(
+				`Could not load ${langName} from dist directory, trying npm package: ${distError instanceof Error ? distError.message : distError}`,
 			)
-			throw error
+
+			// Strategy 2: Try to load from node_modules using require.resolve
+			try {
+				const packageName = `@usagi-coffee/tree-sitter-${langName}`
+				const wasmPath = require.resolve(`${packageName}/tree-sitter-${langName}.wasm`)
+				return await Language.load(wasmPath)
+			} catch (npmError) {
+				console.warn(
+					`Could not load ${langName} from npm package, trying alternative path: ${npmError instanceof Error ? npmError.message : npmError}`,
+				)
+
+				// Strategy 3: Try to load from node_modules with direct path
+				try {
+					const wasmPath = path.join(
+						__dirname,
+						"..",
+						"..",
+						"..",
+						"node_modules",
+						`@usagi-coffee/tree-sitter-${langName}`,
+						`tree-sitter-${langName}.wasm`,
+					)
+					return await Language.load(wasmPath)
+				} catch (fallbackError) {
+					console.error(
+						`Failed to load ${langName} language from all strategies: ${fallbackError instanceof Error ? fallbackError.message : fallbackError}`,
+					)
+					throw new Error(
+						`Unable to load ${langName} language parser. Please ensure the extension is properly installed.`,
+					)
+				}
+			}
 		}
 	}
 
+	// Standard loading for other languages
 	const wasmPath = path.join(baseDir, `tree-sitter-${langName}.wasm`)
 
 	try {
-		const { Language } = require("web-tree-sitter")
 		return await Language.load(wasmPath)
 	} catch (error) {
 		console.error(`Error loading language: ${wasmPath}: ${error instanceof Error ? error.message : error}`)