min / max

Track the minimum or maximum value of a property within an array.

Signature

min<ArrayName extends string, TPropName extends string>(
  arrayName: ArrayName,
  propertyName: keyof ArrayItem & string,
  outputProperty: TPropName
): PipelineBuilder</* type with outputProperty: number | undefined */>

max<ArrayName extends string, TPropName extends string>(
  arrayName: ArrayName,
  propertyName: keyof ArrayItem & string,
  outputProperty: TPropName
): PipelineBuilder</* type with outputProperty: number | undefined */>

Parameters

Parameter	Type	Description
arrayName	string	Name of the array to search
propertyName	string	Name of the property to compare
outputProperty	string	Name of the new min/max property

Returns

A new PipelineBuilder with the min/max property added. Returns undefined for empty arrays.

Example

const builder = createPipeline<Product>()
  .groupBy(["category"], "items")
  .min("items", "price", "lowestPrice")
  .max("items", "price", "highestPrice");

Result:

{
  key: "hash_Electronics",
  value: {
    category: "Electronics",
    lowestPrice: 299,
    highestPrice: 1499,
    items: [...]
  }
}

Update Behavior

Add:

• If new value < current min → update min
• If new value > current max → update max
• O(1) operation

Remove:

• If removed value was the min/max → rescan all items
• O(n) operation in worst case

TIP

If you only add items (never remove), min/max operations are always O(1).

Handling Edge Cases

• Empty array: Returns undefined
• Null/undefined values: Ignored in comparison
• Single item: That item's value is both min and max

See Also

• pickByMin / pickByMax - Get the entire item, not just the value
• average - Compute average