fix: merge default options into user defined options instead of overr…

…iding them

docs/docs/06_plugins/01_available-plugins/01-transactional/04-pg-promise-adapter.md

@@ -57,8 +57,6 @@ ClsModule.forRoot({
 
 The `tx` property on the `TransactionHost<TransactionalAdapterPgPromise>` is typed as [`Database`](https://vitaly-t.github.io/pg-promise/Database.html).
 
-`@Transactional()` takes an optional argument that is the same as the `option` argument to `Database.tx()` in `pg-promise` ([docs](https://vitaly-t.github.io/pg-promise/Database.html#tx)).
-
 ## Example
 
 ```ts title="user.service.ts"

packages/transactional-adapters/transactional-adapter-pg-promise/src/lib/transactional-adapter-pg-promise.ts

@@ -11,6 +11,10 @@ export interface PgPromiseTransactionalAdapterOptions {
      */
     dbInstanceToken: any;
 
+    /**
+     * Default options for the transaction. These will be merged with any transaction-specific options
+     * passed to the `@Transactional` decorator or the `TransactionHost#withTransaction` method.
+     */
     defaultTxOptions?: TxOptions;
 }
 
@@ -33,7 +37,7 @@ export class TransactionalAdapterPgPromise
             setClient: (client?: Database) => void,
         ) => {
             return pgPromiseDbInstance.tx(
-                options ?? this.defaultTxOptions ?? {},
+                { ...this.defaultTxOptions, ...options },
                 (tx) => {
                     setClient(tx as unknown as Database);
                     return fn();