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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
import { assertEquals } from "../testing/asserts.ts";import { groupBy } from "./group_by.ts";
function groupByTest<T>( input: [Array<T>, (el: T) => string], expected: { [x: string]: Array<T> }, message?: string,) { const actual = groupBy(...input); assertEquals(actual, expected, message);}
Deno.test({ name: "[collections/groupBy] no mutation", fn() { const arrayA = [1.1, 4.2, 4.5]; groupBy(arrayA, () => "test");
assertEquals(arrayA, [1.1, 4.2, 4.5]); },});
Deno.test({ name: "[collections/groupBy] empty input", fn() { groupByTest( [[], () => "a"], {}, ); },});
Deno.test({ name: "[collections/groupBy] constant key", fn() { groupByTest( [[1, 3, 5, 6], () => "a"], { a: [1, 3, 5, 6] }, ); },});
Deno.test({ name: "[collections/groupBy] empty key", fn() { groupByTest( [ ["Foo", "b"], (it) => it.charAt(1), ], { "o": ["Foo"], "": ["b"], }, ); },});
Deno.test({ name: "[collections/groupBy] groups", fn() { groupByTest( [ ["Anna", "Marija", "Karl", "Arnold", "Martha"], (it) => it.charAt(0), ], { "A": ["Anna", "Arnold"], "M": ["Marija", "Martha"], "K": ["Karl"], }, ); groupByTest( [ [1.2, 2, 2.3, 6.3, 6.9, 6], (it) => Math.floor(it).toString(), ], { "1": [1.2], "2": [2, 2.3], "6": [6.3, 6.9, 6], }, ); },});