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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
import { assertEquals } from "../testing/asserts.ts";import { findSingle } from "./find_single.ts";
function findSingleTest<I>(  input: [Array<I>, (element: I) => boolean],  expected: I | undefined,  message?: string,) {  const actual = findSingle(...input);  assertEquals(actual, expected, message);}
Deno.test({  name: "[collections/findSingle] no mutation",  fn() {    const array = [1, 2, 3];    findSingle(array, (it) => it % 2 === 0);
    assertEquals(array, [1, 2, 3]);  },});
Deno.test({  name: "[collections/findSingle] empty input",  fn() {    findSingleTest(      [[], (_) => true],      undefined,    );  },});
Deno.test({  name: "[collections/findSingle] only one element",  fn() {    findSingleTest(      [[42], (_it) => true],      42,    );    findSingleTest(      [["foo"], (_it) => true],      "foo",    );    findSingleTest(      [[null], (_it) => true],      null,    );    findSingleTest(      [[undefined], (_it) => true],      undefined,    );  },});
Deno.test({  name: "[collections/findSingle] no matches",  fn() {    findSingleTest(      [[9, 11, 13], (it) => it % 2 === 0],      undefined,    );    findSingleTest(      [["foo", "bar"], (it) => it.startsWith("z")],      undefined,    );    findSingleTest(      [[{ done: false }], (it) => it.done],      undefined,    );  },});
Deno.test({  name: "[collections/findSingle] only match",  fn() {    findSingleTest(      [[9, 12, 13], (it) => it % 2 === 0],      12,    );    findSingleTest(      [["zap", "foo", "bar"], (it) => it.startsWith("z")],      "zap",    );    findSingleTest(      [[{ done: false }, { done: true }], (it) => it.done],      { done: true },    );  },});
Deno.test({  name: "[collections/findSingle] multiple matches",  fn() {    findSingleTest(      [[9, 12, 13, 14], (it) => it % 2 === 0],      undefined,    );    findSingleTest(      [["zap", "foo", "bar", "zee"], (it) => it.startsWith("z")],      undefined,    );  },});