vsfilter

A type-safe, lightweight filter utility for filtering objects by property predicates.

Installation

npm install vsfilter

Usage

import { filter, Filter } from "vsfilter";

Filter an array

Pass an array and one or more filter objects. All conditions must match (AND logic).

const people = [
  { name: "Liam", age: 29 },
  { name: "Charlotte", age: 28 },
  { name: "Frank", age: 52 },
];

const result = filter(people, [
  { name: (name) => name.startsWith("L") },
  { age: (age) => age < 30 },
]);
// => [{ name: "Liam", age: 29 }]

Filter a single object

Returns true if the object matches, false otherwise.

const person = { name: "Liam", age: 29 };

filter(person, { name: (name) => name === "Liam" }); // => true
filter(person, { age: (age) => age > 30 });          // => false

Use inline with Array.filter

const people = [
  { name: "Liam", age: 29 },
  { name: "Charlotte", age: 28 },
  { name: "Frank", age: 52 },
];

const result = people.filter((person) =>
  filter(person, { name: (name) => name.startsWith("L") })
);
// => [{ name: "Liam", age: 29 }]

Multiple conditions in one filter

Conditions within the same filter object are also AND'd together:

const result = filter(people, {
  name: (name) => name.length > 4,
  age: (age) => age < 30,
});
// => [{ name: "Charlotte", age: 28 }]

API

filter<T>(input: T[], filters): T[]

Filters an array, returning items that match all filter conditions.

filter<T>(input: T, filters): boolean

Checks if a single object matches all filter conditions.

Filter<T>

Type for a filter object. Keys are property names, values are predicate functions:

type Filter<T> = {
  [K in keyof T]?: (value: T[K]) => boolean;
};

License

MIT