fix: support async import for DataSource in CLI typeorm#8914 (typeorm…

…#8917)

* Fix: await DataSource from export file to support async loading

* fix: prettier errors

* updated code style

Co-authored-by: Umed Khudoiberdiev <pleerock.me@gmail.com>

src/commands/CommandUtils.ts

@@ -34,11 +34,13 @@ export class CommandUtils {
         }
 
         const dataSourceExports = []
-        for (let fileExport in dataSourceFileExports) {
-            if (
-                InstanceChecker.isDataSource(dataSourceFileExports[fileExport])
-            ) {
-                dataSourceExports.push(dataSourceFileExports[fileExport])
+        for (const fileExport of dataSourceFileExports) {
+            // It is necessary to await here in case of the exported async value (Promise<DataSource>).
+            // e.g. the DataSource is instantiated with an async factory in the source file
+            const awaitedFileExport =
+                fileExport instanceof Promise ? await fileExport : fileExport
+            if (InstanceChecker.isDataSource(awaitedFileExport)) {
+                dataSourceExports.push(awaitedFileExport)
             }
         }