Add server config for mergable extensions

frontend/sync-client/src/services/server-config.ts

@@ -0,0 +1,67 @@
+import { createPromise } from "../utils/create-promise";
+import type { SyncService } from "./sync-service";
+import type { PingResponse } from "./types/PingResponse";
+
+export interface ServerConfigData {
+	mergeableFileExtensions: string[];
+}
+
+export class ServerConfig {
+	private response: Promise<PingResponse> | undefined;
+	private config: ServerConfigData | undefined;
+
+	public constructor(private readonly syncService: SyncService) {}
+
+	public async initialize(): Promise<void> {
+		this.response = this.syncService.ping();
+		this.config = await this.response;
+	}
+
+	public async checkConnection(forceUpdate = false): Promise<{
+		isSuccessful: boolean;
+		message: string;
+	}> {
+		try {
+			let { response } = this;
+			if (!response && !forceUpdate) {
+				throw new Error("ServerConfig not initialized");
+			} else if (forceUpdate) {
+				response = this.response = this.syncService.ping();
+			}
+
+			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+			const result: PingResponse = (await response)!; // it must be defined, otherwise we would have thrown above
+			this.config = result;
+
+			if (result.isAuthenticated) {
+				return {
+					isSuccessful: true,
+					message: `Successfully connected to server (version: ${result.serverVersion}) and authenticated`
+				};
+			}
+
+			return {
+				isSuccessful: false,
+				message: `Successfully connected to server (version: ${result.serverVersion}) but failed to authenticate`
+			};
+		} catch (e) {
+			return {
+				isSuccessful: false,
+				message: `Failed to connect to server: ${e}`
+			};
+		}
+	}
+
+	public getConfig(): ServerConfigData {
+		if (!this.config) {
+			throw new Error("ServerConfig not initialized");
+		}
+
+		return this.config;
+	}
+
+	public reset(): void {
+		this.response = undefined;
+		this.config = undefined;
+	}
+}

frontend/sync-client/src/services/sync-service.ts

@@ -302,40 +302,24 @@ export class SyncService {
 		});
 	}
 
-	public async checkConnection(): Promise<{
-		isSuccessful: boolean;
-		message: string;
-	}> {
-		try {
-			const response = await this.pingClient(this.getUrl("/ping"), {
-				headers: this.getDefaultHeaders()
-			});
-			const result: PingResponse | SerializedError =
-				(await response.json()) as PingResponse | SerializedError; // eslint-disable-line @typescript-eslint/no-unsafe-type-assertion
+	public async ping(): Promise<PingResponse> {
+		const response = await this.pingClient(this.getUrl("/ping"), {
+			headers: this.getDefaultHeaders()
+		});
+		const result: PingResponse | SerializedError =
+			(await response.json()) as PingResponse | SerializedError; // eslint-disable-line @typescript-eslint/no-unsafe-type-assertion
 
-			if ("errorType" in result) {
-				throw new Error(
-					`Failed to ping server: ${SyncService.formatError(result)}`
-				);
-			}
-
-			if (result.isAuthenticated) {
-				return {
-					isSuccessful: true,
-					message: `Successfully connected to server (version: ${result.serverVersion}) and authenticated`
-				};
-			}
-
-			return {
-				isSuccessful: false,
-				message: `Successfully connected to server (version: ${result.serverVersion}) but failed to authenticate`
-			};
-		} catch (e) {
-			return {
-				isSuccessful: false,
-				message: `Failed to connect to server: ${e}`
-			};
+		if ("errorType" in result) {
+			throw new Error(
+				`Failed to ping server: ${SyncService.formatError(result)}`
+			);
 		}
+
+		this.logger.debug(
+			`Pinged server, got response: ${JSON.stringify(result)}`
+		);
+
+		return result;
 	}
 
 	private getUrl(path: string): string {

frontend/sync-client/src/services/types/PingResponse.ts

@@ -13,4 +13,8 @@ export interface PingResponse {
 	 * header.
 	 */
 	isAuthenticated: boolean;
+	/**
+	 * List of file extensions that are allowed to be merged.
+	 */
+	mergeableFileExtensions: string[];
 }