pub fn make_column(columns: &[&str]) -> String {
columns.join(" , ")
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_make_column_empty() {
assert_eq!(make_column(&[]), "");
}
#[test]
fn test_make_column_single() {
assert_eq!(make_column(&["id"]), "id");
}
#[test]
fn test_make_column_multiple() {
assert_eq!(make_column(&["id", "name", "email"]), "id , name , email");
}
#[test]
fn test_make_column_wildcard() {
assert_eq!(make_column(&["*"]), "*");
}
}