How to Add Expense Lines Reliably in NetSuite Client-Side Scripts

When encountering issues with line item manipulation in client-side SuiteScripts, it is recommended to utilize synchronous mode when setting line fields. This ensures predictable script execution by forcing the script to wait for any specified sourcing to complete before continuing.The SuiteScript 2.x function currentRecord.setCurrentSublistValue includes an option for synchronous execution:

currentRecord.setCurrentSublistValue(options)

The fireSlavingSync option within this function is relevant for client SuiteScripts. In server scripts (such as user event scripts), this option will always execute as true. In client scripts, if the fireSlavingSync option is not explicitly set, its default value is false, and the API executes asynchronously. If set to true, this API executes synchronously, which ensures predictable script execution. Setting fireSlavingSync to true forces the client script to wait on any specified sourcing before continuing with the rest of the script.A common reason for issues with expense lines is interference from the Tax Nexus. If synchronous mode (i.e., fireSlavingSync: true) is not used, setting the tax code value may not allow the Tax Nexus to fetch the necessary tax code information. This can prevent the line from being successfully saved.