cmp.go

Documentation: cloud.google.com/go/internal/testutil

     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  
    15  package testutil
    16  
    17  import (
    18  	"math"
    19  	"math/big"
    20  
    21  	"github.com/google/go-cmp/cmp"
    22  	"google.golang.org/protobuf/proto"
    23  )
    24  
    25  var (
    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.
    49  func 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).
    57  func 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
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