Match function names to behavior

Function names and their documentation must accurately reflect what the function actually does. When a function handles more data than its name suggests, either rename the function or split the functionality.

In the example below, formatDate() actually formats both date and time components, making the name misleading:

/**
 * Formats the given date as a string in the form "YYYYMMdd".
 */
function formatDate(date: Date): string {
    const year = date.getFullYear().toString().padStart(4, "0");
    const month = (date.getMonth() + 1).toString().padStart(2, "0");
    const day = date.getDate().toString().padStart(2, "0");
    const hour = date.getHours().toString().padStart(2, "0");
    const minute = date.getMinutes().toString().padStart(2, "0");
    const seconds = date.getSeconds().toString().padStart(2, "0");
    return year + month + day + hour + minute + seconds;
}

Better approaches:

• Rename to formatDateTime() and update documentation to “YYYYMMddTHHMMSS”
• Keep formatDate() but remove time components
• Split into separate formatDate() and formatTime() functions

This prevents confusion about what data the function processes and ensures the API is self-documenting.