restic/vendor/cloud.google.com/go/internal/testutil/cmp.go
2017-08-06 21:47:56 +02:00

99 lines
3 KiB
Go

// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package testutil
import (
"fmt"
"math"
"reflect"
"unicode"
"unicode/utf8"
"github.com/golang/protobuf/proto"
"github.com/google/go-cmp/cmp"
)
var (
alwaysEqual = cmp.Comparer(func(_, _ interface{}) bool { return true })
defaultCmpOptions = []cmp.Option{
// Use proto.Equal for protobufs
cmp.Comparer(proto.Equal),
// NaNs compare equal
cmp.FilterValues(func(x, y float64) bool {
return math.IsNaN(x) && math.IsNaN(y)
}, alwaysEqual),
cmp.FilterValues(func(x, y float32) bool {
return math.IsNaN(float64(x)) && math.IsNaN(float64(y))
}, alwaysEqual),
}
)
// Equal tests two values for equality.
func Equal(x, y interface{}, opts ...cmp.Option) bool {
// Put default options at the end. Order doesn't matter.
opts = append(opts[:len(opts):len(opts)], defaultCmpOptions...)
return cmp.Equal(x, y, opts...)
}
// Diff reports the differences between two values.
// Diff(x, y) == "" iff Equal(x, y).
func Diff(x, y interface{}, opts ...cmp.Option) string {
// Put default options at the end. Order doesn't matter.
opts = append(opts[:len(opts):len(opts)], defaultCmpOptions...)
return cmp.Diff(x, y, opts...)
}
// TODO(jba): remove the code below when cmpopts becomes available.
// IgnoreUnexported returns an Option that only ignores the immediate unexported
// fields of a struct, including anonymous fields of unexported types.
// In particular, unexported fields within the struct's exported fields
// of struct types, including anonymous fields, will not be ignored unless the
// type of the field itself is also passed to IgnoreUnexported.
func IgnoreUnexported(typs ...interface{}) cmp.Option {
ux := newUnexportedFilter(typs...)
return cmp.FilterPath(ux.filter, cmp.Ignore())
}
type unexportedFilter struct{ m map[reflect.Type]bool }
func newUnexportedFilter(typs ...interface{}) unexportedFilter {
ux := unexportedFilter{m: make(map[reflect.Type]bool)}
for _, typ := range typs {
t := reflect.TypeOf(typ)
if t == nil || t.Kind() != reflect.Struct {
panic(fmt.Sprintf("invalid struct type: %T", typ))
}
ux.m[t] = true
}
return ux
}
func (xf unexportedFilter) filter(p cmp.Path) bool {
if len(p) < 2 {
return false
}
sf, ok := p[len(p)-1].(cmp.StructField)
if !ok {
return false
}
return xf.m[p[len(p)-2].Type()] && !isExported(sf.Name())
}
// isExported reports whether the identifier is exported.
func isExported(id string) bool {
r, _ := utf8.DecodeRuneInString(id)
return unicode.IsUpper(r)
}