fix: Auto reconnection to the database server is not triggered

deps.ts

@@ -11,6 +11,11 @@ export {
   configLogger as configMySQLLogger,
   Connection as MySQLConnection,
 } from "https://deno.land/x/[email protected]/mod.ts";
+
+export {
+  ResponseTimeoutError as MySQLReponseTimeoutError
+} from "https://deno.land/x/[email protected]/src/constant/errors.ts";
+
 export type { LoggerConfig } from "https://deno.land/x/[email protected]/mod.ts";
 
 export { Client as PostgresClient } from "https://deno.land/x/[email protected]/mod.ts";

lib/connectors/mysql-connector.ts

@@ -1,9 +1,10 @@
-import { configMySQLLogger, MySQLClient, MySQLConnection } from "../../deps.ts";
+import { configMySQLLogger, MySQLClient, MySQLConnection, MySQLReponseTimeoutError } from "../../deps.ts";
 import type { LoggerConfig } from "../../deps.ts";
 import type { Connector, ConnectorOptions } from "./connector.ts";
 import { SQLTranslator } from "../translators/sql-translator.ts";
 import type { SupportedSQLDatabaseDialect } from "../translators/sql-translator.ts";
 import type { QueryDescription } from "../query-builder.ts";
+import { warning } from "../helpers/log.ts";
 
 export interface MySQLOptions extends ConnectorOptions {
   database: string;
@@ -13,6 +14,8 @@ export interface MySQLOptions extends ConnectorOptions {
   port?: number;
   charset?: string;
   logger?: LoggerConfig;
+  idleTimeout?: number;
+  reconnectOnTimeout?: boolean
 }
 
 export class MySQLConnector implements Connector {
@@ -46,6 +49,7 @@ export class MySQLConnector implements Connector {
       password: this._options.password,
       port: this._options.port ?? 3306,
       charset: this._options.charset ?? "utf8",
+      idleTimeout: this._options.idleTimeout
     });
 
     this._connected = true;
@@ -62,9 +66,15 @@ export class MySQLConnector implements Connector {
     }
   }
 
+  /**
+   * Executing query
+   * @param queryDescription {QueryDescription}
+   * @param client {MySQLClient | MySQLConnection}
+   * @param reconnectAttempt {boolean} - Used for reconnect client when ResponseTimeoutError happened
+   */
   async query(
     queryDescription: QueryDescription,
-    client?: MySQLClient | MySQLConnection,
+    client?: MySQLClient | MySQLConnection
   ): Promise<any | any[]> {
     await this._makeConnection();
 
@@ -76,7 +86,23 @@ export class MySQLConnector implements Connector {
       : "execute";
 
     for (let i = 0; i < subqueries.length; i++) {
-      const result = await queryClient[queryMethod](subqueries[i]);
+      let result = null;
+
+      try {
+        result = await queryClient[queryMethod](subqueries[i]);
+      }
+      catch (error) {
+
+        //reconnect client on timeout error
+        if (this._options.reconnectOnTimeout && error instanceof MySQLReponseTimeoutError) {
+          //reconnect client, at this moment we can't subscribe to connectionState of mysql driver, we need to do this
+          await this.reconnect();
+
+          return this.query(queryDescription, client);
+        }
+
+        throw error;
+      }
 
       if (i === subqueries.length - 1) {
         return result;
@@ -88,6 +114,17 @@ export class MySQLConnector implements Connector {
     return this._client.transaction(queries);
   }
 
+
+  /**
+   * Reconnect client connection
+   */
+  async reconnect() {
+    warning("Client reconnection has been triggered.");
+
+    await this.close();
+    return this._makeConnection();
+  }
+
   async close() {
     if (!this._connected) {
       return;