Today was dedicated to intensive debugging of function errors that appeared in our calendar events system after the migration. These issues were primarily related to how event data is processed and rendered in different calendar views, particularly when integrating with the newly refactored time tracking module.
I began by systematically documenting all the observed error conditions, reproducing each one in a controlled environment to understand its exact trigger. This methodical approach revealed several distinct issues rather than a single root cause:
First, I discovered timing issues in how event listeners were being attached to dynamically generated calendar elements. In some cases, the event handlers were being registered before the DOM elements were fully rendered, resulting in missing click or drag functionality. I resolved this by implementing a more robust initialization sequence that ensures elements are fully rendered before attaching handlers, with additional checks that re-attach handlers when views change or new elements are added.
A more complex issue involved the data transformation layer between our backend API and the calendar component. Certain fields were being incorrectly formatted or missing entirely when shifts had associated time tracking data. The problem stemmed from inconsistent naming conventions between our old and new systems—some properties used camelCase in one system but snake_case in another. I standardized the API response format and created a comprehensive data mapper that ensures all necessary fields are correctly transformed regardless of their source format.
I also addressed several edge cases related to recurring shifts. When a single occurrence of a recurring shift had attendance data associated with it, the system sometimes incorrectly applied that attendance status to all occurrences in the calendar view. I fixed this by modifying how the unique identifiers for shift occurrences are generated and processed, ensuring that attendance data is correctly associated only with the specific occurrence it belongs to.
One particularly elusive bug involved timezone handling for shifts that span midnight. In certain cases, these shifts would appear incorrectly split across days or with incorrect durations. After extensive debugging, I traced the issue to how date objects were being serialized and deserialized between the frontend and backend. The solution required implementing consistent timezone handling throughout the entire pipeline, using UTC for all internal storage and API communication while converting to local time only at the display layer.
For each fix implemented, I created corresponding automated tests to verify the solution and prevent regression in the future. These tests simulate various calendar operations and verify that the system behaves correctly in all identified edge cases.
By the end of the day, I had resolved most of the critical function errors, though a few minor issues remain to be addressed tomorrow. The calendar system now correctly displays shifts with their associated attendance status in most scenarios, providing managers with the at-a-glance information they need to monitor team performance.