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// Copyright 2023 The Go 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 cmp_test
import (
"cmp"
"math"
"sort"
"testing"
)
var negzero = math.Copysign(0, -1)
var tests = []struct {
x, y any
compare int
}{
{1, 2, -1},
{1, 1, 0},
{2, 1, +1},
{"a", "aa", -1},
{"a", "a", 0},
{"aa", "a", +1},
{1.0, 1.1, -1},
{1.1, 1.1, 0},
{1.1, 1.0, +1},
{math.Inf(1), math.Inf(1), 0},
{math.Inf(-1), math.Inf(-1), 0},
{math.Inf(-1), 1.0, -1},
{1.0, math.Inf(-1), +1},
{math.Inf(1), 1.0, +1},
{1.0, math.Inf(1), -1},
{math.NaN(), math.NaN(), 0},
{0.0, math.NaN(), +1},
{math.NaN(), 0.0, -1},
{math.NaN(), math.Inf(-1), -1},
{math.Inf(-1), math.NaN(), +1},
{0.0, 0.0, 0},
{negzero, negzero, 0},
{negzero, 0.0, 0},
{0.0, negzero, 0},
{negzero, 1.0, -1},
{negzero, -1.0, +1},
}
func TestLess(t *testing.T) {
for _, test := range tests {
var b bool
switch test.x.(type) {
case int:
b = cmp.Less(test.x.(int), test.y.(int))
case string:
b = cmp.Less(test.x.(string), test.y.(string))
case float64:
b = cmp.Less(test.x.(float64), test.y.(float64))
}
if b != (test.compare < 0) {
t.Errorf("Less(%v, %v) == %t, want %t", test.x, test.y, b, test.compare < 0)
}
}
}
func TestCompare(t *testing.T) {
for _, test := range tests {
var c int
switch test.x.(type) {
case int:
c = cmp.Compare(test.x.(int), test.y.(int))
case string:
c = cmp.Compare(test.x.(string), test.y.(string))
case float64:
c = cmp.Compare(test.x.(float64), test.y.(float64))
}
if c != test.compare {
t.Errorf("Compare(%v, %v) == %d, want %d", test.x, test.y, c, test.compare)
}
}
}
func TestSort(t *testing.T) {
// Test that our comparison function is consistent with
// sort.Float64s.
input := []float64{1.0, 0.0, negzero, math.Inf(1), math.Inf(-1), math.NaN()}
sort.Float64s(input)
for i := 0; i < len(input)-1; i++ {
if cmp.Less(input[i+1], input[i]) {
t.Errorf("Less sort mismatch at %d in %v", i, input)
}
if cmp.Compare(input[i], input[i+1]) > 0 {
t.Errorf("Compare sort mismatch at %d in %v", i, input)
}
}
}