Add package cmp for performing equality of Go values

The API of the package is as follows:
    func Equal(x, y interface{}, opts ...Option) bool
    func Diff(x, y interface{}, opts ...Option) string

    type Option interface{ ... }
        func Ignore() Option
        func Comparer(f interface{}) Option
        func Transformer(name string, f interface{}) Option

        func FilterPath(f func(Path) bool, opt Option) Option
        func FilterValues(f interface{}, opt Option) Option

        func AllowUnexported(typs ...interface{}) Option
    type Options []Option

    type Path []PathStep
    type PathStep interface{ ... }

    type Indirect interface{ ... }
    type StructField interface{ ... }
    type MapIndex interface{ ... }
    type SliceIndex interface{ ... }
    type TypeAssertion interface{ ... }
    type Transform interface{ ... }

See the package docs in compare.go for a high-level view of this package.

6 files changed, 873 insertions, 0 deletions

diff --git a/cmp/internal/testprotos/protos.go b/cmp/internal/testprotos/protos.go
new file mode 100644
index 0000000..120c8b0
--- /dev/null
+++ b/cmp/internal/testprotos/protos.go
@@ -0,0 +1,116 @@
+// 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 testprotos
+
+func Equal(x, y Message) bool {
+	if x == nil || y == nil {
+		return x == nil && y == nil
+	}
+	return x.String() == y.String()
+}
+
+type Message interface {
+	Proto()
+	String() string
+}
+
+type proto interface {
+	Proto()
+}
+
+type notComparable struct {
+	unexportedField func()
+}
+
+type Stringer struct{ X string }
+
+func (s *Stringer) String() string { return s.X }
+
+// Project1 protocol buffers
+type (
+	Eagle_States         int
+	Eagle_MissingCalls   int
+	Dreamer_States       int
+	Dreamer_MissingCalls int
+	Slap_States          int
+	Goat_States          int
+	Donkey_States        int
+	SummerType           int
+
+	Eagle struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Dreamer struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Slap struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Goat struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Donkey struct {
+		proto
+		notComparable
+		Stringer
+	}
+)
+
+// Project2 protocol buffers
+type (
+	Germ struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Dish struct {
+		proto
+		notComparable
+		Stringer
+	}
+)
+
+// Project3 protocol buffers
+type (
+	Dirt struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Wizard struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Sadistic struct {
+		proto
+		notComparable
+		Stringer
+	}
+)
+
+// Project4 protocol buffers
+type (
+	HoneyStatus int
+	PoisonType  int
+	MetaData    struct {
+		proto
+		notComparable
+		Stringer
+	}
+	Restrictions struct {
+		proto
+		notComparable
+		Stringer
+	}
+)
diff --git a/cmp/internal/teststructs/project1.go b/cmp/internal/teststructs/project1.go
new file mode 100644
index 0000000..1999e38
--- /dev/null
+++ b/cmp/internal/teststructs/project1.go
@@ -0,0 +1,267 @@
+// 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 teststructs
+
+import (
+	"time"
+
+	pb "github.com/google/go-cmp/cmp/internal/testprotos"
+)
+
+// This is an sanitized example of equality from a real use-case.
+// The original equality function was as follows:
+/*
+func equalEagle(x, y Eagle) bool {
+	if x.Name != y.Name &&
+		!reflect.DeepEqual(x.Hounds, y.Hounds) &&
+		x.Desc != y.Desc &&
+		x.DescLong != y.DescLong &&
+		x.Prong != y.Prong &&
+		x.StateGoverner != y.StateGoverner &&
+		x.PrankRating != y.PrankRating &&
+		x.FunnyPrank != y.FunnyPrank &&
+		!pb.Equal(x.Immutable.Proto(), y.Immutable.Proto()) {
+		return false
+	}
+
+	if len(x.Dreamers) != len(y.Dreamers) {
+		return false
+	}
+	for i := range x.Dreamers {
+		if !equalDreamer(x.Dreamers[i], y.Dreamers[i]) {
+			return false
+		}
+	}
+	if len(x.Slaps) != len(y.Slaps) {
+		return false
+	}
+	for i := range x.Slaps {
+		if !equalSlap(x.Slaps[i], y.Slaps[i]) {
+			return false
+		}
+	}
+	return true
+}
+func equalDreamer(x, y Dreamer) bool {
+	if x.Name != y.Name ||
+		x.Desc != y.Desc ||
+		x.DescLong != y.DescLong ||
+		x.ContSlapsInterval != y.ContSlapsInterval ||
+		x.Ornamental != y.Ornamental ||
+		x.Amoeba != y.Amoeba ||
+		x.Heroes != y.Heroes ||
+		x.FloppyDisk != y.FloppyDisk ||
+		x.MightiestDuck != y.MightiestDuck ||
+		x.FunnyPrank != y.FunnyPrank ||
+		!pb.Equal(x.Immutable.Proto(), y.Immutable.Proto()) {
+
+		return false
+	}
+	if len(x.Animal) != len(y.Animal) {
+		return false
+	}
+	for i := range x.Animal {
+		vx := x.Animal[i]
+		vy := y.Animal[i]
+		if reflect.TypeOf(x.Animal) != reflect.TypeOf(y.Animal) {
+			return false
+		}
+		switch vx.(type) {
+		case Goat:
+			if !equalGoat(vx.(Goat), vy.(Goat)) {
+				return false
+			}
+		case Donkey:
+			if !equalDonkey(vx.(Donkey), vy.(Donkey)) {
+				return false
+			}
+		default:
+			panic(fmt.Sprintf("unknown type: %T", vx))
+		}
+	}
+	if len(x.PreSlaps) != len(y.PreSlaps) {
+		return false
+	}
+	for i := range x.PreSlaps {
+		if !equalSlap(x.PreSlaps[i], y.PreSlaps[i]) {
+			return false
+		}
+	}
+	if len(x.ContSlaps) != len(y.ContSlaps) {
+		return false
+	}
+	for i := range x.ContSlaps {
+		if !equalSlap(x.ContSlaps[i], y.ContSlaps[i]) {
+			return false
+		}
+	}
+	return true
+}
+func equalSlap(x, y Slap) bool {
+	return x.Name == y.Name &&
+		x.Desc == y.Desc &&
+		x.DescLong == y.DescLong &&
+		pb.Equal(x.Args, y.Args) &&
+		x.Tense == y.Tense &&
+		x.Interval == y.Interval &&
+		x.Homeland == y.Homeland &&
+		x.FunnyPrank == y.FunnyPrank &&
+		pb.Equal(x.Immutable.Proto(), y.Immutable.Proto())
+}
+func equalGoat(x, y Goat) bool {
+	if x.Target != y.Target ||
+		x.FunnyPrank != y.FunnyPrank ||
+		!pb.Equal(x.Immutable.Proto(), y.Immutable.Proto()) {
+		return false
+	}
+	if len(x.Slaps) != len(y.Slaps) {
+		return false
+	}
+	for i := range x.Slaps {
+		if !equalSlap(x.Slaps[i], y.Slaps[i]) {
+			return false
+		}
+	}
+	return true
+}
+func equalDonkey(x, y Donkey) bool {
+	return x.Pause == y.Pause &&
+		x.Sleep == y.Sleep &&
+		x.FunnyPrank == y.FunnyPrank &&
+		pb.Equal(x.Immutable.Proto(), y.Immutable.Proto())
+}
+*/
+
+type Eagle struct {
+	Name          string
+	Hounds        []string
+	Desc          string
+	DescLong      string
+	Dreamers      []Dreamer
+	Prong         int64
+	Slaps         []Slap
+	StateGoverner string
+	PrankRating   string
+	FunnyPrank    string
+	Immutable     *EagleImmutable
+}
+
+type EagleImmutable struct {
+	ID          string
+	State       *pb.Eagle_States
+	MissingCall *pb.Eagle_MissingCalls
+	Birthday    time.Time
+	Death       time.Time
+	Started     time.Time
+	LastUpdate  time.Time
+	Creator     string
+	empty       bool
+}
+
+type Dreamer struct {
+	Name              string
+	Desc              string
+	DescLong          string
+	PreSlaps          []Slap
+	ContSlaps         []Slap
+	ContSlapsInterval int32
+	Animal            []interface{} // Could be either Goat or Donkey
+	Ornamental        bool
+	Amoeba            int64
+	Heroes            int32
+	FloppyDisk        int32
+	MightiestDuck     bool
+	FunnyPrank        string
+	Immutable         *DreamerImmutable
+}
+
+type DreamerImmutable struct {
+	ID          string
+	State       *pb.Dreamer_States
+	MissingCall *pb.Dreamer_MissingCalls
+	Calls       int32
+	Started     time.Time
+	Stopped     time.Time
+	LastUpdate  time.Time
+	empty       bool
+}
+
+type Slap struct {
+	Name       string
+	Desc       string
+	DescLong   string
+	Args       pb.Message
+	Tense      int32
+	Interval   int32
+	Homeland   uint32
+	FunnyPrank string
+	Immutable  *SlapImmutable
+}
+
+type SlapImmutable struct {
+	ID          string
+	Out         pb.Message
+	MildSlap    bool
+	PrettyPrint string
+	State       *pb.Slap_States
+	Started     time.Time
+	Stopped     time.Time
+	LastUpdate  time.Time
+	LoveRadius  *LoveRadius
+	empty       bool
+}
+
+type Goat struct {
+	Target     string
+	Slaps      []Slap
+	FunnyPrank string
+	Immutable  *GoatImmutable
+}
+
+type GoatImmutable struct {
+	ID         string
+	State      *pb.Goat_States
+	Started    time.Time
+	Stopped    time.Time
+	LastUpdate time.Time
+	empty      bool
+}
+type Donkey struct {
+	Pause      bool
+	Sleep      int32
+	FunnyPrank string
+	Immutable  *DonkeyImmutable
+}
+
+type DonkeyImmutable struct {
+	ID         string
+	State      *pb.Donkey_States
+	Started    time.Time
+	Stopped    time.Time
+	LastUpdate time.Time
+	empty      bool
+}
+
+type LoveRadius struct {
+	Summer *SummerLove
+	empty  bool
+}
+
+type SummerLove struct {
+	Summary *SummerLoveSummary
+	empty   bool
+}
+
+type SummerLoveSummary struct {
+	Devices    []string
+	ChangeType []pb.SummerType
+	empty      bool
+}
+
+func (EagleImmutable) Proto() *pb.Eagle     { return nil }
+func (DreamerImmutable) Proto() *pb.Dreamer { return nil }
+func (SlapImmutable) Proto() *pb.Slap       { return nil }
+func (GoatImmutable) Proto() *pb.Goat       { return nil }
+func (DonkeyImmutable) Proto() *pb.Donkey   { return nil }
diff --git a/cmp/internal/teststructs/project2.go b/cmp/internal/teststructs/project2.go
new file mode 100644
index 0000000..536592b
--- /dev/null
+++ b/cmp/internal/teststructs/project2.go
@@ -0,0 +1,74 @@
+// 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 teststructs
+
+import (
+	"time"
+
+	pb "github.com/google/go-cmp/cmp/internal/testprotos"
+)
+
+// This is an sanitized example of equality from a real use-case.
+// The original equality function was as follows:
+/*
+func equalBatch(b1, b2 *GermBatch) bool {
+	for _, b := range []*GermBatch{b1, b2} {
+		for _, l := range b.DirtyGerms {
+			sort.Slice(l, func(i, j int) bool { return l[i].String() < l[j].String() })
+		}
+		for _, l := range b.CleanGerms {
+			sort.Slice(l, func(i, j int) bool { return l[i].String() < l[j].String() })
+		}
+	}
+	if !pb.DeepEqual(b1.DirtyGerms, b2.DirtyGerms) ||
+		!pb.DeepEqual(b1.CleanGerms, b2.CleanGerms) ||
+		!pb.DeepEqual(b1.GermMap, b2.GermMap) {
+		return false
+	}
+	if len(b1.DishMap) != len(b2.DishMap) {
+		return false
+	}
+	for id := range b1.DishMap {
+		kpb1, err1 := b1.DishMap[id].Proto()
+		kpb2, err2 := b2.DishMap[id].Proto()
+		if !pb.Equal(kpb1, kpb2) || !reflect.DeepEqual(err1, err2) {
+			return false
+		}
+	}
+	return b1.HasPreviousResult == b2.HasPreviousResult &&
+		b1.DirtyID == b2.DirtyID &&
+		b1.CleanID == b2.CleanID &&
+		b1.GermStrain == b2.GermStrain &&
+		b1.TotalDirtyGerms == b2.TotalDirtyGerms &&
+		b1.InfectedAt.Equal(b2.InfectedAt)
+}
+*/
+
+type GermBatch struct {
+	DirtyGerms, CleanGerms map[int32][]*pb.Germ
+	GermMap                map[int32]*pb.Germ
+	DishMap                map[int32]*Dish
+	HasPreviousResult      bool
+	DirtyID, CleanID       int32
+	GermStrain             int32
+	TotalDirtyGerms        int
+	InfectedAt             time.Time
+}
+
+type Dish struct {
+	pb  *pb.Dish
+	err error
+}
+
+func CreateDish(m *pb.Dish, err error) *Dish {
+	return &Dish{pb: m, err: err}
+}
+
+func (d *Dish) Proto() (*pb.Dish, error) {
+	if d.err != nil {
+		return nil, d.err
+	}
+	return d.pb, nil
+}
diff --git a/cmp/internal/teststructs/project3.go b/cmp/internal/teststructs/project3.go
new file mode 100644
index 0000000..00c252e
--- /dev/null
+++ b/cmp/internal/teststructs/project3.go
@@ -0,0 +1,77 @@
+// 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 teststructs
+
+import (
+	"sync"
+
+	pb "github.com/google/go-cmp/cmp/internal/testprotos"
+)
+
+// This is an sanitized example of equality from a real use-case.
+// The original equality function was as follows:
+/*
+func equalDirt(x, y *Dirt) bool {
+	if !reflect.DeepEqual(x.table, y.table) ||
+		!reflect.DeepEqual(x.ts, y.ts) ||
+		x.Discord != y.Discord ||
+		!pb.Equal(&x.Proto, &y.Proto) ||
+		len(x.wizard) != len(y.wizard) ||
+		len(x.sadistic) != len(y.sadistic) ||
+		x.lastTime != y.lastTime {
+		return false
+	}
+	for k, vx := range x.wizard {
+		vy, ok := y.wizard[k]
+		if !ok || !pb.Equal(vx, vy) {
+			return false
+		}
+	}
+	for k, vx := range x.sadistic {
+		vy, ok := y.sadistic[k]
+		if !ok || !pb.Equal(vx, vy) {
+			return false
+		}
+	}
+	return true
+}
+*/
+
+type Dirt struct {
+	table    Table // Always concrete type of MockTable
+	ts       Timestamp
+	Discord  DiscordState
+	Proto    pb.Dirt
+	wizard   map[string]*pb.Wizard
+	sadistic map[string]*pb.Sadistic
+	lastTime int64
+	mu       sync.Mutex
+}
+
+type DiscordState int
+
+type Timestamp int64
+
+func (d *Dirt) SetTable(t Table)                      { d.table = t }
+func (d *Dirt) SetTimestamp(t Timestamp)              { d.ts = t }
+func (d *Dirt) SetWizard(m map[string]*pb.Wizard)     { d.wizard = m }
+func (d *Dirt) SetSadistic(m map[string]*pb.Sadistic) { d.sadistic = m }
+func (d *Dirt) SetLastTime(t int64)                   { d.lastTime = t }
+
+type Table interface {
+	Operation1() error
+	Operation2() error
+	Operation3() error
+}
+
+type MockTable struct {
+	state []string
+}
+
+func CreateMockTable(s []string) *MockTable { return &MockTable{s} }
+func (mt *MockTable) Operation1() error     { return nil }
+func (mt *MockTable) Operation2() error     { return nil }
+func (mt *MockTable) Operation3() error     { return nil }
+func (mt *MockTable) State() []string       { return mt.state }
diff --git a/cmp/internal/teststructs/project4.go b/cmp/internal/teststructs/project4.go
new file mode 100644
index 0000000..9b50d73
--- /dev/null
+++ b/cmp/internal/teststructs/project4.go
@@ -0,0 +1,142 @@
+// 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 teststructs
+
+import (
+	"time"
+
+	pb "github.com/google/go-cmp/cmp/internal/testprotos"
+)
+
+// This is an sanitized example of equality from a real use-case.
+// The original equality function was as follows:
+/*
+func equalCartel(x, y Cartel) bool {
+	if !(equalHeadquarter(x.Headquarter, y.Headquarter) &&
+		x.Source() == y.Source() &&
+		x.CreationDate().Equal(y.CreationDate()) &&
+		x.Boss() == y.Boss() &&
+		x.LastCrimeDate().Equal(y.LastCrimeDate())) {
+		return false
+	}
+	if len(x.Poisons()) != len(y.Poisons()) {
+		return false
+	}
+	for i := range x.Poisons() {
+		if !equalPoison(*x.Poisons()[i], *y.Poisons()[i]) {
+			return false
+		}
+	}
+	return true
+}
+func equalHeadquarter(x, y Headquarter) bool {
+	xr, yr := x.Restrictions(), y.Restrictions()
+	return x.ID() == y.ID() &&
+		x.Location() == y.Location() &&
+		reflect.DeepEqual(x.SubDivisions(), y.SubDivisions()) &&
+		x.IncorporatedDate().Equal(y.IncorporatedDate()) &&
+		pb.Equal(x.MetaData(), y.MetaData()) &&
+		bytes.Equal(x.PrivateMessage(), y.PrivateMessage()) &&
+		bytes.Equal(x.PublicMessage(), y.PublicMessage()) &&
+		x.HorseBack() == y.HorseBack() &&
+		x.Rattle() == y.Rattle() &&
+		x.Convulsion() == y.Convulsion() &&
+		x.Expansion() == y.Expansion() &&
+		x.Status() == y.Status() &&
+		pb.Equal(&xr, &yr) &&
+		x.CreationTime().Equal(y.CreationTime())
+}
+func equalPoison(x, y Poison) bool {
+	return x.PoisonType() == y.PoisonType() &&
+		x.Expiration().Equal(y.Expiration()) &&
+		x.Manufactuer() == y.Manufactuer() &&
+		x.Potency() == y.Potency()
+}
+*/
+
+type Cartel struct {
+	Headquarter
+	source        string
+	creationDate  time.Time
+	boss          string
+	lastCrimeDate time.Time
+	poisons       []*Poison
+}
+
+func (p Cartel) Source() string           { return p.source }
+func (p Cartel) CreationDate() time.Time  { return p.creationDate }
+func (p Cartel) Boss() string             { return p.boss }
+func (p Cartel) LastCrimeDate() time.Time { return p.lastCrimeDate }
+func (p Cartel) Poisons() []*Poison       { return p.poisons }
+
+func (p *Cartel) SetSource(x string)           { p.source = x }
+func (p *Cartel) SetCreationDate(x time.Time)  { p.creationDate = x }
+func (p *Cartel) SetBoss(x string)             { p.boss = x }
+func (p *Cartel) SetLastCrimeDate(x time.Time) { p.lastCrimeDate = x }
+func (p *Cartel) SetPoisons(x []*Poison)       { p.poisons = x }
+
+type Headquarter struct {
+	id               uint64
+	location         string
+	subDivisions     []string
+	incorporatedDate time.Time
+	metaData         *pb.MetaData
+	privateMessage   []byte
+	publicMessage    []byte
+	horseBack        string
+	rattle           string
+	convulsion       bool
+	expansion        uint64
+	status           pb.HoneyStatus
+	restrictions     pb.Restrictions
+	creationTime     time.Time
+}
+
+func (hq Headquarter) ID() uint64                    { return hq.id }
+func (hq Headquarter) Location() string              { return hq.location }
+func (hq Headquarter) SubDivisions() []string        { return hq.subDivisions }
+func (hq Headquarter) IncorporatedDate() time.Time   { return hq.incorporatedDate }
+func (hq Headquarter) MetaData() *pb.MetaData        { return hq.metaData }
+func (hq Headquarter) PrivateMessage() []byte        { return hq.privateMessage }
+func (hq Headquarter) PublicMessage() []byte         { return hq.publicMessage }
+func (hq Headquarter) HorseBack() string             { return hq.horseBack }
+func (hq Headquarter) Rattle() string                { return hq.rattle }
+func (hq Headquarter) Convulsion() bool              { return hq.convulsion }
+func (hq Headquarter) Expansion() uint64             { return hq.expansion }
+func (hq Headquarter) Status() pb.HoneyStatus        { return hq.status }
+func (hq Headquarter) Restrictions() pb.Restrictions { return hq.restrictions }
+func (hq Headquarter) CreationTime() time.Time       { return hq.creationTime }
+
+func (hq *Headquarter) SetID(x uint64)                    { hq.id = x }
+func (hq *Headquarter) SetLocation(x string)              { hq.location = x }
+func (hq *Headquarter) SetSubDivisions(x []string)        { hq.subDivisions = x }
+func (hq *Headquarter) SetIncorporatedDate(x time.Time)   { hq.incorporatedDate = x }
+func (hq *Headquarter) SetMetaData(x *pb.MetaData)        { hq.metaData = x }
+func (hq *Headquarter) SetPrivateMessage(x []byte)        { hq.privateMessage = x }
+func (hq *Headquarter) SetPublicMessage(x []byte)         { hq.publicMessage = x }
+func (hq *Headquarter) SetHorseBack(x string)             { hq.horseBack = x }
+func (hq *Headquarter) SetRattle(x string)                { hq.rattle = x }
+func (hq *Headquarter) SetConvulsion(x bool)              { hq.convulsion = x }
+func (hq *Headquarter) SetExpansion(x uint64)             { hq.expansion = x }
+func (hq *Headquarter) SetStatus(x pb.HoneyStatus)        { hq.status = x }
+func (hq *Headquarter) SetRestrictions(x pb.Restrictions) { hq.restrictions = x }
+func (hq *Headquarter) SetCreationTime(x time.Time)       { hq.creationTime = x }
+
+type Poison struct {
+	poisonType  pb.PoisonType
+	expiration  time.Time
+	manufactuer string
+	potency     int
+}
+
+func (p Poison) PoisonType() pb.PoisonType { return p.poisonType }
+func (p Poison) Expiration() time.Time     { return p.expiration }
+func (p Poison) Manufactuer() string       { return p.manufactuer }
+func (p Poison) Potency() int              { return p.potency }
+
+func (p *Poison) SetPoisonType(x pb.PoisonType) { p.poisonType = x }
+func (p *Poison) SetExpiration(x time.Time)     { p.expiration = x }
+func (p *Poison) SetManufactuer(x string)       { p.manufactuer = x }
+func (p *Poison) SetPotency(x int)              { p.potency = x }
diff --git a/cmp/internal/teststructs/structs.go b/cmp/internal/teststructs/structs.go
new file mode 100644
index 0000000..6b4d2a7
--- /dev/null
+++ b/cmp/internal/teststructs/structs.go
@@ -0,0 +1,197 @@
+// 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 teststructs
+
+type InterfaceA interface {
+	InterfaceA()
+}
+
+type (
+	StructA struct{ X string } // Equal method on value receiver
+	StructB struct{ X string } // Equal method on pointer receiver
+	StructC struct{ X string } // Equal method (with interface argument) on value receiver
+	StructD struct{ X string } // Equal method (with interface argument) on pointer receiver
+	StructE struct{ X string } // Equal method (with interface argument on value receiver) on pointer receiver
+	StructF struct{ X string } // Equal method (with interface argument on pointer receiver) on value receiver
+
+	// These embed the above types as a value.
+	StructA1 struct {
+		StructA
+		X string
+	}
+	StructB1 struct {
+		StructB
+		X string
+	}
+	StructC1 struct {
+		StructC
+		X string
+	}
+	StructD1 struct {
+		StructD
+		X string
+	}
+	StructE1 struct {
+		StructE
+		X string
+	}
+	StructF1 struct {
+		StructF
+		X string
+	}
+
+	// These embed the above types as a pointer.
+	StructA2 struct {
+		*StructA
+		X string
+	}
+	StructB2 struct {
+		*StructB
+		X string
+	}
+	StructC2 struct {
+		*StructC
+		X string
+	}
+	StructD2 struct {
+		*StructD
+		X string
+	}
+	StructE2 struct {
+		*StructE
+		X string
+	}
+	StructF2 struct {
+		*StructF
+		X string
+	}
+
+	StructNo struct{ X string } // Equal method (with interface argument) on non-satisfying receiver
+
+	AssignA func() int
+	AssignB struct{ A int }
+	AssignC chan bool
+	AssignD <-chan bool
+)
+
+func (x StructA) Equal(y StructA) bool     { return true }
+func (x *StructB) Equal(y *StructB) bool   { return true }
+func (x StructC) Equal(y InterfaceA) bool  { return true }
+func (x StructC) InterfaceA()              {}
+func (x *StructD) Equal(y InterfaceA) bool { return true }
+func (x *StructD) InterfaceA()             {}
+func (x *StructE) Equal(y InterfaceA) bool { return true }
+func (x StructE) InterfaceA()              {}
+func (x StructF) Equal(y InterfaceA) bool  { return true }
+func (x *StructF) InterfaceA()             {}
+func (x StructNo) Equal(y InterfaceA) bool { return true }
+
+func (x AssignA) Equal(y func() int) bool      { return true }
+func (x AssignB) Equal(y struct{ A int }) bool { return true }
+func (x AssignC) Equal(y chan bool) bool       { return true }
+func (x AssignD) Equal(y <-chan bool) bool     { return true }
+
+var _ = func(
+	a StructA, b StructB, c StructC, d StructD, e StructE, f StructF,
+	ap *StructA, bp *StructB, cp *StructC, dp *StructD, ep *StructE, fp *StructF,
+	a1 StructA1, b1 StructB1, c1 StructC1, d1 StructD1, e1 StructE1, f1 StructF1,
+	a2 StructA2, b2 StructB2, c2 StructC2, d2 StructD2, e2 StructE2, f2 StructF1,
+) {
+	a.Equal(a)
+	b.Equal(&b)
+	c.Equal(c)
+	d.Equal(&d)
+	e.Equal(e)
+	f.Equal(&f)
+
+	ap.Equal(*ap)
+	bp.Equal(bp)
+	cp.Equal(*cp)
+	dp.Equal(dp)
+	ep.Equal(*ep)
+	fp.Equal(fp)
+
+	a1.Equal(a1.StructA)
+	b1.Equal(&b1.StructB)
+	c1.Equal(c1)
+	d1.Equal(&d1)
+	e1.Equal(e1)
+	f1.Equal(&f1)
+
+	a2.Equal(*a2.StructA)
+	b2.Equal(b2.StructB)
+	c2.Equal(c2)
+	d2.Equal(&d2)
+	e2.Equal(e2)
+	f2.Equal(&f2)
+}
+
+type (
+	privateStruct struct{ Public, private int }
+	PublicStruct  struct{ Public, private int }
+	ParentStructA struct{ privateStruct }
+	ParentStructB struct{ PublicStruct }
+	ParentStructC struct {
+		privateStruct
+		Public, private int
+	}
+	ParentStructD struct {
+		PublicStruct
+		Public, private int
+	}
+	ParentStructE struct {
+		privateStruct
+		PublicStruct
+	}
+	ParentStructF struct {
+		privateStruct
+		PublicStruct
+		Public, private int
+	}
+	ParentStructG struct {
+		*privateStruct
+	}
+	ParentStructH struct {
+		*PublicStruct
+	}
+	ParentStructI struct {
+		*privateStruct
+		*PublicStruct
+	}
+	ParentStructJ struct {
+		*privateStruct
+		*PublicStruct
+		Public  PublicStruct
+		private privateStruct
+	}
+)
+
+func NewParentStructG() *ParentStructG {
+	return &ParentStructG{new(privateStruct)}
+}
+func NewParentStructH() *ParentStructH {
+	return &ParentStructH{new(PublicStruct)}
+}
+func NewParentStructI() *ParentStructI {
+	return &ParentStructI{new(privateStruct), new(PublicStruct)}
+}
+func NewParentStructJ() *ParentStructJ {
+	return &ParentStructJ{
+		privateStruct: new(privateStruct), PublicStruct: new(PublicStruct),
+	}
+}
+func (s *privateStruct) SetPrivate(i int)              { s.private = i }
+func (s *PublicStruct) SetPrivate(i int)               { s.private = i }
+func (s *ParentStructC) SetPrivate(i int)              { s.private = i }
+func (s *ParentStructD) SetPrivate(i int)              { s.private = i }
+func (s *ParentStructF) SetPrivate(i int)              { s.private = i }
+func (s *ParentStructA) PrivateStruct() *privateStruct { return &s.privateStruct }
+func (s *ParentStructC) PrivateStruct() *privateStruct { return &s.privateStruct }
+func (s *ParentStructE) PrivateStruct() *privateStruct { return &s.privateStruct }
+func (s *ParentStructF) PrivateStruct() *privateStruct { return &s.privateStruct }
+func (s *ParentStructG) PrivateStruct() *privateStruct { return s.privateStruct }
+func (s *ParentStructI) PrivateStruct() *privateStruct { return s.privateStruct }
+func (s *ParentStructJ) PrivateStruct() *privateStruct { return s.privateStruct }
+func (s *ParentStructJ) Private() *privateStruct       { return &s.private }