functools/functools_test.go

// Copyright 2022 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package functools

import (
	"math"
	"testing"

	"golang.org/x/exp/slices"
)

func TestFilter(t *testing.T) {
	original := []string{"foo", "bar", "baz"}
	got := Filter(original, func(s string) bool { return s == "bar" })
	want := []string{"bar"}
	if !slices.Equal(got, want) {
		t.Errorf("Filter returned wrong slice, got %s, wanted %s", got, want)
	}
}

func TestSortBy(t *testing.T) {
	slice := []int{4, -2, 1, 4, -10, 3}

	SortBy(slice, func(x int) float64 {
		return math.Abs(float64(x))
	})

	// The numbers should end up sorted by absolute value.
	want := []int{1, -2, 3, 4, 4, -10}
	if !slices.Equal(slice, want) {
		t.Errorf("SortBy incorrect, got %d, wanted %d", slice, want)
	}
}