From e4f56e3877fa25a5556e0f803b02a7c745d40240 Mon Sep 17 00:00:00 2001
From: Andrew Beal <andrew.business@tuta.com>
Date: Fri, 19 Dec 2025 12:36:28 +0000
Subject: [PATCH] refactor: improve type safety in file service and error
 handling

- Change listFiles() to synchronous method returning cached IDs
- Add type predicate to ApiError.isApiError() for better type narrowing
- Remove redundant ApiError union type in retry error handling
---
 AIClasses/BaseAIFileService.ts | 4 ++--
 AIClasses/IAIFileService.ts    | 2 +-
 Types/ApiError.ts              | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/AIClasses/BaseAIFileService.ts b/AIClasses/BaseAIFileService.ts
index 92df8be..ef2ec72 100644
--- a/AIClasses/BaseAIFileService.ts
+++ b/AIClasses/BaseAIFileService.ts
@@ -35,7 +35,7 @@ export abstract class BaseAIFileService implements IAIFileService {
 		this.fileIDs = await this.listFilesFromAPI();
 	}
 
-	public async listFiles(): Promise<string[]> {
+	public listFiles(): string[] {
 		return [...this.fileIDs];
 	}
 
@@ -78,7 +78,7 @@ export abstract class BaseAIFileService implements IAIFileService {
 
 	// Retries operation on retryable errors (500, 502, 503, 504) with exponential backoff
 	protected async withRetry<T>(operationName: string, operation: () => Promise<T>): Promise<T> {
-		let lastError: ApiError | unknown;
+		let lastError: unknown;
 
 		for (let attempt = 1; attempt <= BaseAIFileService.MAX_RETRIES; attempt++) {
 			try {
diff --git a/AIClasses/IAIFileService.ts b/AIClasses/IAIFileService.ts
index edacdab..fc59c10 100644
--- a/AIClasses/IAIFileService.ts
+++ b/AIClasses/IAIFileService.ts
@@ -2,7 +2,7 @@ import type { Attachment } from "Conversations/Attachment";
 
 export interface IAIFileService {
     refreshCache(): Promise<void>;
-    listFiles(): Promise<string[]>;
+    listFiles(): string[];
     uploadFile(attachment: Attachment): Promise<string>;
     deleteFile(attachment: Attachment): Promise<void>;
 }
\ No newline at end of file
diff --git a/Types/ApiError.ts b/Types/ApiError.ts
index ed2d39a..4044d5c 100644
--- a/Types/ApiError.ts
+++ b/Types/ApiError.ts
@@ -23,7 +23,7 @@ export class ApiError extends Error {
         this.name = "ApiError";
     }
 
-    static isApiError(error: unknown): boolean {
+    static isApiError(error: unknown): error is ApiError {
         return error instanceof ApiError;
     }