union

union(target, source)

Returns a new set containing all unique values from both the target set and the source set.

data-first

union(new Set([1, 2]), new Set([2, 3, 4])); // Set([1, 2, 3, 4])
union(new Set([1, 2]), new Set([3, 4])); // Set([1, 2, 3, 4])

data-last

pipe(new Set([1, 2]), union(new Set([2, 3, 4]))); // Set([1, 2, 3, 4])
pipe(new Set([1, 2]), union(new Set([3, 4]))); // Set([1, 2, 3, 4])