fix: new user case in createDataset_service fn

Make `createDataset_service` function creates a new user
datasets docment if the user has not one,

Create `successfulDatasetCreation` to reuse it to register the
new dataset creation activity and to return the success result

Also cancel using transaction session because there is
only one write operation and there is no need to transactions.

Also delete failedDatasetCreation method from
`operationsResultsMessages` object because its usage is
strange and doesn't have a clear reason behind it.

src/constants/operationsResultsMessages.ts

@@ -2,8 +2,6 @@ const operationsResultsMessages = {
   successfulDatasetCreation: (datasetName: string) =>
     `"${datasetName}" dataset created successfuly`,
   successfulDatasetUpdate: "The dataset was updated successfully",
-  failedDatasetCreation: (datasetName: string) =>
-    `"${datasetName}" dataset creation failed`,
   noDatasets: "There are no datasets yet",
   noDataset: (datasetId: string) =>
     `There is no dataset with "${datasetId}" id`,

src/services/datasets/createDataset_service.ts

@@ -1,4 +1,3 @@
-import createTransactionSession from "../../utilities/createTransactionSession";
 import DatasetsModel from "../../models/DatasetsModel";
 import { DatasetDocument, type DatasetInput } from "../../types/datasets";
 import type { ServiceOperationResultType } from "../../types/response";
@@ -11,8 +10,6 @@ export default async function createDataset_service(
   userId: string,
   dataset: DatasetInput
 ): Promise<ServiceOperationResultType> {
-  const session = await createTransactionSession();
-
   const newDataset = new DatasetDocument(dataset);
 
   const userDatasets = await DatasetsModel.findById(
@@ -21,40 +18,42 @@ export default async function createDataset_service(
     { upsert: true }
   );
 
-  if (userDatasets && userDatasets.datasets.length < maxDatasetsForUser) {
-    userDatasets.datasets.push(newDataset);
-    const datasetAdded = await userDatasets
-      .save({ session })
-      .then(() => true)
-      .catch(() => false);
-
-    if (datasetAdded) {
-      await session.commitTransaction();
-      activitiesService.registerDatasetActivity(
-        userId,
-        {
-          _id: newDataset._id,
-          name: newDataset.name,
-          description: newDataset.description,
-        },
-        newDataset.createdAt,
-        "New Resource"
-      );
-
-      return ServiceOperationResult.success(
-        newDataset,
-        operationsResultsMessages.successfulDatasetCreation(newDataset.name)
-      );
-    }
+  if (!userDatasets) {
+    await DatasetsModel.create({
+      _id: userId,
+      datasets: [newDataset],
+    });
+    return successfulDatasetCreation(userId, newDataset);
+  }
 
-    session.abortTransaction();
-    return ServiceOperationResult.failure(
-      operationsResultsMessages.failedDatasetCreation(newDataset.name)
-    );
+  if (userDatasets.datasets.length < maxDatasetsForUser) {
+    userDatasets.datasets.push(newDataset);
+    await userDatasets.save();
+    return successfulDatasetCreation(userId, newDataset);
   } else {
-    session.abortTransaction();
     return ServiceOperationResult.failure(
       operationsResultsMessages.maxDatasetsReached
     );
   }
 }
+
+function successfulDatasetCreation(
+  userId: string,
+  newDataset: DatasetDocument
+) {
+  activitiesService.registerDatasetActivity(
+    userId,
+    {
+      _id: newDataset._id,
+      name: newDataset.name,
+      description: newDataset.description,
+    },
+    newDataset.createdAt,
+    "New Resource"
+  );
+
+  return ServiceOperationResult.success(
+    newDataset,
+    operationsResultsMessages.successfulDatasetCreation(newDataset.name)
+  );
+}