@applicaster/zapp-react-native-utils/utils/__tests__/find.test.ts

Applicaster Zapp React Native utilities package

import { find } from "../find";

test("example 1", () => {
  const predicate = <T>(_: T, index: number): boolean => index === 0;
  const xs = ["1", "2", "2", "3", "4"];

  expect(find(predicate, xs)).toBe("1");
});

test("example 2", () => {
  const predicate = <T>(_: T, index: number): boolean => index === 0;
  const xs: string[] = [];

  expect(find(predicate, xs)).toBe(undefined);
});

test("example 3", () => {
  const predicate = () => false;
  const xs = ["1", "2", "2", "3"];

  expect(find(predicate, xs)).toBe(undefined);
});

test("example 4", () => {
  const predicate = <T>(_: T, index: number): boolean => index === 1;
  const xs = ["1", "2", "2", "3"];

  expect(find(predicate, xs)).toBe("2");
});

test("example 5", () => {
  const predicate = <T>(_: T, index: number): boolean => index === 2;
  const xs = ["1", "2.1", "2", "3", "2", "4"];

  expect(find(predicate, xs)).toBe("2");
});