--- /dev/null
+// Copyright 2017, 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.md file.
+
+package cmpopts
+
+import (
+ "fmt"
+ "reflect"
+ "unicode"
+ "unicode/utf8"
+
+ "github.com/google/go-cmp/cmp"
+ "github.com/google/go-cmp/cmp/internal/function"
+)
+
+// IgnoreFields returns an Option that ignores fields of the
+// given names on a single struct type. It respects the names of exported fields
+// that are forwarded due to struct embedding.
+// The struct type is specified by passing in a value of that type.
+//
+// The name may be a dot-delimited string (e.g., "Foo.Bar") to ignore a
+// specific sub-field that is embedded or nested within the parent struct.
+func IgnoreFields(typ interface{}, names ...string) cmp.Option {
+ sf := newStructFilter(typ, names...)
+ return cmp.FilterPath(sf.filter, cmp.Ignore())
+}
+
+// IgnoreTypes returns an Option that ignores all values assignable to
+// certain types, which are specified by passing in a value of each type.
+func IgnoreTypes(typs ...interface{}) cmp.Option {
+ tf := newTypeFilter(typs...)
+ return cmp.FilterPath(tf.filter, cmp.Ignore())
+}
+
+type typeFilter []reflect.Type
+
+func newTypeFilter(typs ...interface{}) (tf typeFilter) {
+ for _, typ := range typs {
+ t := reflect.TypeOf(typ)
+ if t == nil {
+ // This occurs if someone tries to pass in sync.Locker(nil)
+ panic("cannot determine type; consider using IgnoreInterfaces")
+ }
+ tf = append(tf, t)
+ }
+ return tf
+}
+func (tf typeFilter) filter(p cmp.Path) bool {
+ if len(p) < 1 {
+ return false
+ }
+ t := p.Last().Type()
+ for _, ti := range tf {
+ if t.AssignableTo(ti) {
+ return true
+ }
+ }
+ return false
+}
+
+// IgnoreInterfaces returns an Option that ignores all values or references of
+// values assignable to certain interface types. These interfaces are specified
+// by passing in an anonymous struct with the interface types embedded in it.
+// For example, to ignore sync.Locker, pass in struct{sync.Locker}{}.
+func IgnoreInterfaces(ifaces interface{}) cmp.Option {
+ tf := newIfaceFilter(ifaces)
+ return cmp.FilterPath(tf.filter, cmp.Ignore())
+}
+
+type ifaceFilter []reflect.Type
+
+func newIfaceFilter(ifaces interface{}) (tf ifaceFilter) {
+ t := reflect.TypeOf(ifaces)
+ if ifaces == nil || t.Name() != "" || t.Kind() != reflect.Struct {
+ panic("input must be an anonymous struct")
+ }
+ for i := 0; i < t.NumField(); i++ {
+ fi := t.Field(i)
+ switch {
+ case !fi.Anonymous:
+ panic("struct cannot have named fields")
+ case fi.Type.Kind() != reflect.Interface:
+ panic("embedded field must be an interface type")
+ case fi.Type.NumMethod() == 0:
+ // This matches everything; why would you ever want this?
+ panic("cannot ignore empty interface")
+ default:
+ tf = append(tf, fi.Type)
+ }
+ }
+ return tf
+}
+func (tf ifaceFilter) filter(p cmp.Path) bool {
+ if len(p) < 1 {
+ return false
+ }
+ t := p.Last().Type()
+ for _, ti := range tf {
+ if t.AssignableTo(ti) {
+ return true
+ }
+ if t.Kind() != reflect.Ptr && reflect.PtrTo(t).AssignableTo(ti) {
+ return true
+ }
+ }
+ return false
+}
+
+// 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.
+//
+// Avoid ignoring unexported fields of a type which you do not control (i.e. a
+// type from another repository), as changes to the implementation of such types
+// may change how the comparison behaves. Prefer a custom Comparer instead.
+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("%T must be a non-pointer struct", typ))
+ }
+ ux.m[t] = true
+ }
+ return ux
+}
+func (xf unexportedFilter) filter(p cmp.Path) bool {
+ sf, ok := p.Index(-1).(cmp.StructField)
+ if !ok {
+ return false
+ }
+ return xf.m[p.Index(-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)
+}
+
+// IgnoreSliceElements returns an Option that ignores elements of []V.
+// The discard function must be of the form "func(T) bool" which is used to
+// ignore slice elements of type V, where V is assignable to T.
+// Elements are ignored if the function reports true.
+func IgnoreSliceElements(discardFunc interface{}) cmp.Option {
+ vf := reflect.ValueOf(discardFunc)
+ if !function.IsType(vf.Type(), function.ValuePredicate) || vf.IsNil() {
+ panic(fmt.Sprintf("invalid discard function: %T", discardFunc))
+ }
+ return cmp.FilterPath(func(p cmp.Path) bool {
+ si, ok := p.Index(-1).(cmp.SliceIndex)
+ if !ok {
+ return false
+ }
+ if !si.Type().AssignableTo(vf.Type().In(0)) {
+ return false
+ }
+ vx, vy := si.Values()
+ if vx.IsValid() && vf.Call([]reflect.Value{vx})[0].Bool() {
+ return true
+ }
+ if vy.IsValid() && vf.Call([]reflect.Value{vy})[0].Bool() {
+ return true
+ }
+ return false
+ }, cmp.Ignore())
+}
+
+// IgnoreMapEntries returns an Option that ignores entries of map[K]V.
+// The discard function must be of the form "func(T, R) bool" which is used to
+// ignore map entries of type K and V, where K and V are assignable to T and R.
+// Entries are ignored if the function reports true.
+func IgnoreMapEntries(discardFunc interface{}) cmp.Option {
+ vf := reflect.ValueOf(discardFunc)
+ if !function.IsType(vf.Type(), function.KeyValuePredicate) || vf.IsNil() {
+ panic(fmt.Sprintf("invalid discard function: %T", discardFunc))
+ }
+ return cmp.FilterPath(func(p cmp.Path) bool {
+ mi, ok := p.Index(-1).(cmp.MapIndex)
+ if !ok {
+ return false
+ }
+ if !mi.Key().Type().AssignableTo(vf.Type().In(0)) || !mi.Type().AssignableTo(vf.Type().In(1)) {
+ return false
+ }
+ k := mi.Key()
+ vx, vy := mi.Values()
+ if vx.IsValid() && vf.Call([]reflect.Value{k, vx})[0].Bool() {
+ return true
+ }
+ if vy.IsValid() && vf.Call([]reflect.Value{k, vy})[0].Bool() {
+ return true
+ }
+ return false
+ }, cmp.Ignore())
+}