[Performance] Simplify getAllReportErrors and improve its performance

[OlimpiaZurek]

Problem

The current implementation of getAllReportErrors function faces few performance and optimization issues. It uses the reduce method to accumulate errors, which can be less efficient, especially for large datasets. Additionally, combining error objects with object spread syntax introduces unnecessary overhead, potentially slowing down the function.

Similarly, the hasSmartscanError function has complex logic with nested conditions, leading to potential performance bottlenecks.

Solution

Refactor the getAllReportErrors, replacing complex methods with more efficient alternatives. Replacing reduce method with a for...of loop will improve performance, especially for large datasets. Additionally, the use of Object. assign instead of object spread syntax seems more efficient and may reduce memory usage

Additionally, adding early returns and simplify condition checks in hasSmartscanError should improve efficiency of getAllReportErrors.

 function getAllReportErrors(report: OnyxEntry<Report>, reportActions: OnyxEntry<ReportActions>): OnyxCommon.Errors {
     const reportErrors = report?.errors ?? {};
     const reportErrorFields = report?.errorFields ?? {};
-    const reportActionErrors: OnyxCommon.ErrorFields = Object.values(reportActions ?? {}).reduce((prevReportActionErrors, action) => {
-        if (!action || isEmptyObject(action.errors)) {
-            return prevReportActionErrors;
-        }
+    const reportActionsArray = Object.values(reportActions ?? {});
+    const reportActionErrors: OnyxCommon.ErrorFields = {};
 
-        return Object.assign(prevReportActionErrors, action.errors);
-    }, {});
+    for (const action of reportActionsArray) {
+        if (action && !isEmptyObject(action.errors)) {
+            Object.assign(reportActionErrors, action.errors);
+        }
+    }
     const parentReportAction: OnyxEntry<ReportAction> =
         !report?.parentReportID || !report?.parentReportActionID ? undefined : allReportActions?.[report.parentReportID ?? '-1']?.[report.parentReportActionID ?? '-1'];
 
@@ -543,24 +544,22 @@ function getAllReportErrors(report: OnyxEntry<Report>, reportActions: OnyxEntry<
         if (ReportUtils.shouldShowRBRForMissingSmartscanFields(report?.reportID ?? '-1') && !ReportUtils.isSettled(report?.reportID)) {
             reportActionErrors.smartscan = ErrorUtils.getMicroSecondOnyxErrorWithTranslationKey('iou.error.genericSmartscanFailureMessage');
         }
-    } else if (ReportUtils.hasSmartscanError(Object.values(reportActions ?? {}))) {
+    } else if (ReportUtils.hasSmartscanError(reportActionsArray)) {
         reportActionErrors.smartscan = ErrorUtils.getMicroSecondOnyxErrorWithTranslationKey('iou.error.genericSmartscanFailureMessage');
     }
     // All error objects related to the report. Each object in the sources contains error messages keyed by microtime
-    const errorSources = {
-        reportErrors,
-        ...reportErrorFields,
-        ...reportActionErrors,
-    };
-    // Combine all error messages keyed by microtime into one object
-    const allReportErrors = Object.values(errorSources)?.reduce((prevReportErrors, errors) => {
-        if (isEmptyObject(errors)) {
-            return prevReportErrors;
-        }
+    // eslint-disable-next-line prefer-object-spread
+    const errorSources = Object.assign({}, reportErrors, reportErrorFields, reportActionErrors);
 
-        return Object.assign(prevReportErrors, errors);
-    }, {});
+    // Combine all error messages keyed by microtime into one object
+    const errorSourcesArray = Object.values(errorSources ?? {});
+    const allReportErrors = {};
 
+    for (const errors of errorSourcesArray) {
+        if (!isEmptyObject(errors)) {
+            Object.assign(allReportErrors, errors);
+        }
+    }
     return allReportErrors;
 }

 function hasSmartscanError(reportActions: ReportAction[]) {
     return reportActions.some((action) => {
-        if (!ReportActionsUtils.isSplitBillAction(action) && !ReportActionsUtils.isReportPreviewAction(action)) {
+        const isReportPreview = ReportActionsUtils.isReportPreviewAction(action);
+        const isSplitReportAction = ReportActionsUtils.isSplitBillAction(action);
+        if (!isSplitReportAction && !isReportPreview) {
             return false;
         }
         const IOUReportID = ReportActionsUtils.getIOUReportIDFromReportActionPreview(action);
eportID) && !isSettled(IOUReportID);
D);
+        if (isReportPreviewError) {
+            return true;
+        }
+
ansactionID ?? '-1' : '-1';
         const transaction = allTransactions?.[`${ONYXKEYS.COLLECTION.TRANSACTION}${transactionID}`] ?? {};
ion as Transaction);
+        const isSplitBillError = isSplitReportAction && TransactionUtils.hasMissingSmartscanFields(transaction as Transaction);
 
-        return isReportPreviewError || isSplitBillError;
+        return isSplitBillError;
     });
 }

[melvin-bot]

Auto-assigning issues to engineers is no longer supported. If you think this issue should receive engineering attention, please raise it in #whatsnext.

[OlimpiaZurek]

Hi, I'm Olimpia from Callstack and I would like to work on this issue.

[melvin-bot]

Triggered auto assignment to @flodnv, see https://stackoverflow.com/c/expensify/questions/7972 for more details.

[melvin-bot]

This issue has not been updated in over 15 days. @flodnv eroding to Monthly issue.

P.S. Is everyone reading this sure this is really a near-term priority? Be brave: if you disagree, go ahead and close it out. If someone disagrees, they'll reopen it, and if they don't: one less thing to do!