1// Copyright 2017 Google LLC
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package testutil
16
17import (
18	"math"
19	"math/big"
20
21	"github.com/golang/protobuf/proto"
22	"github.com/google/go-cmp/cmp"
23)
24
25var (
26	alwaysEqual = cmp.Comparer(func(_, _ interface{}) bool { return true })
27
28	defaultCmpOptions = []cmp.Option{
29		// Use proto.Equal for protobufs
30		cmp.Comparer(proto.Equal),
31		// Use big.Rat.Cmp for big.Rats
32		cmp.Comparer(func(x, y *big.Rat) bool {
33			if x == nil || y == nil {
34				return x == y
35			}
36			return x.Cmp(y) == 0
37		}),
38		// NaNs compare equal
39		cmp.FilterValues(func(x, y float64) bool {
40			return math.IsNaN(x) && math.IsNaN(y)
41		}, alwaysEqual),
42		cmp.FilterValues(func(x, y float32) bool {
43			return math.IsNaN(float64(x)) && math.IsNaN(float64(y))
44		}, alwaysEqual),
45	}
46)
47
48// Equal tests two values for equality.
49func Equal(x, y interface{}, opts ...cmp.Option) bool {
50	// Put default options at the end. Order doesn't matter.
51	opts = append(opts[:len(opts):len(opts)], defaultCmpOptions...)
52	return cmp.Equal(x, y, opts...)
53}
54
55// Diff reports the differences between two values.
56// Diff(x, y) == "" iff Equal(x, y).
57func Diff(x, y interface{}, opts ...cmp.Option) string {
58	// Put default options at the end. Order doesn't matter.
59	opts = append(opts[:len(opts):len(opts)], defaultCmpOptions...)
60	return cmp.Diff(x, y, opts...)
61}
62