restic/vendor/cloud.google.com/go/internal/fields/fields_test.go

567 lines
13 KiB
Go

// Copyright 2016 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 fields
import (
"encoding/json"
"errors"
"fmt"
"reflect"
"strings"
"testing"
"time"
"github.com/google/go-cmp/cmp"
"cloud.google.com/go/internal/testutil"
)
type embed1 struct {
Em1 int
Dup int // annihilates with embed2.Dup
Shadow int
embed3
}
type embed2 struct {
Dup int
embed3
embed4
}
type embed3 struct {
Em3 int // annihilated because embed3 is in both embed1 and embed2
embed5
}
type embed4 struct {
Em4 int
Dup int // annihilation of Dup in embed1, embed2 hides this Dup
*embed1 // ignored because it occurs at a higher level
}
type embed5 struct {
x int
}
type Anonymous int
type S1 struct {
Exported int
unexported int
Shadow int // shadows S1.Shadow
embed1
*embed2
Anonymous
}
type Time struct {
time.Time
}
var intType = reflect.TypeOf(int(0))
func field(name string, tval interface{}, index ...int) *Field {
return &Field{
Name: name,
Type: reflect.TypeOf(tval),
Index: index,
}
}
func tfield(name string, tval interface{}, index ...int) *Field {
return &Field{
Name: name,
Type: reflect.TypeOf(tval),
Index: index,
NameFromTag: true,
}
}
func TestFieldsNoTags(t *testing.T) {
c := NewCache(nil, nil, nil)
got, err := c.Fields(reflect.TypeOf(S1{}))
if err != nil {
t.Fatal(err)
}
want := []*Field{
field("Exported", int(0), 0),
field("Shadow", int(0), 2),
field("Em1", int(0), 3, 0),
field("Em4", int(0), 4, 2, 0),
field("Anonymous", Anonymous(0), 5),
}
if msg, ok := compareFields(got, want); !ok {
t.Error(msg)
}
}
func TestAgainstJSONEncodingNoTags(t *testing.T) {
// Demonstrates that this package produces the same set of fields as encoding/json.
s1 := S1{
Exported: 1,
unexported: 2,
Shadow: 3,
embed1: embed1{
Em1: 4,
Dup: 5,
Shadow: 6,
embed3: embed3{
Em3: 7,
embed5: embed5{x: 8},
},
},
embed2: &embed2{
Dup: 9,
embed3: embed3{
Em3: 10,
embed5: embed5{x: 11},
},
embed4: embed4{
Em4: 12,
Dup: 13,
embed1: &embed1{Em1: 14},
},
},
Anonymous: Anonymous(15),
}
var want S1
jsonRoundTrip(t, s1, &want)
var got S1
got.embed2 = &embed2{} // need this because reflection won't create it
fields, err := NewCache(nil, nil, nil).Fields(reflect.TypeOf(got))
if err != nil {
t.Fatal(err)
}
setFields(fields, &got, s1)
if !testutil.Equal(got, want,
cmp.AllowUnexported(S1{}, embed1{}, embed2{}, embed3{}, embed4{}, embed5{})) {
t.Errorf("got\n%+v\nwant\n%+v", got, want)
}
}
// Tests use of LeafTypes parameter to NewCache
func TestAgainstJSONEncodingEmbeddedTime(t *testing.T) {
timeLeafFn := func(t reflect.Type) bool {
return t == reflect.TypeOf(time.Time{})
}
// Demonstrates that this package can produce the same set of
// fields as encoding/json for a struct with an embedded time.Time.
now := time.Now().UTC()
myt := Time{
now,
}
var want Time
jsonRoundTrip(t, myt, &want)
var got Time
fields, err := NewCache(nil, nil, timeLeafFn).Fields(reflect.TypeOf(got))
if err != nil {
t.Fatal(err)
}
setFields(fields, &got, myt)
if !testutil.Equal(got, want) {
t.Errorf("got\n%+v\nwant\n%+v", got, want)
}
}
type S2 struct {
NoTag int
XXX int `json:"tag"` // tag name takes precedence
Anonymous `json:"anon"` // anonymous non-structs also get their name from the tag
unexported int `json:"tag"`
Embed `json:"em"` // embedded structs with tags become fields
Tag int
YYY int `json:"Tag"` // tag takes precedence over untagged field of the same name
Empty int `json:""` // empty tag is noop
tEmbed1
tEmbed2
}
type Embed struct {
Em int
}
type tEmbed1 struct {
Dup int
X int `json:"Dup2"`
}
type tEmbed2 struct {
Y int `json:"Dup"` // takes precedence over tEmbed1.Dup because it is tagged
Z int `json:"Dup2"` // same name as tEmbed1.X and both tagged, so ignored
}
func jsonTagParser(t reflect.StructTag) (name string, keep bool, other interface{}, err error) {
s := t.Get("json")
parts := strings.Split(s, ",")
if parts[0] == "-" {
return "", false, nil, nil
}
if len(parts) > 1 {
other = parts[1:]
}
return parts[0], true, other, nil
}
func validateFunc(t reflect.Type) (err error) {
if t.Kind() != reflect.Struct {
return errors.New("non-struct type used")
}
for i := 0; i < t.NumField(); i++ {
if t.Field(i).Type.Kind() == reflect.Slice {
return fmt.Errorf("slice field found at field %s on struct %s", t.Field(i).Name, t.Name())
}
}
return nil
}
func TestFieldsWithTags(t *testing.T) {
got, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(S2{}))
if err != nil {
t.Fatal(err)
}
want := []*Field{
field("NoTag", int(0), 0),
tfield("tag", int(0), 1),
tfield("anon", Anonymous(0), 2),
tfield("em", Embed{}, 4),
tfield("Tag", int(0), 6),
field("Empty", int(0), 7),
tfield("Dup", int(0), 8, 0),
}
if msg, ok := compareFields(got, want); !ok {
t.Error(msg)
}
}
func TestAgainstJSONEncodingWithTags(t *testing.T) {
// Demonstrates that this package produces the same set of fields as encoding/json.
s2 := S2{
NoTag: 1,
XXX: 2,
Anonymous: 3,
Embed: Embed{
Em: 4,
},
tEmbed1: tEmbed1{
Dup: 5,
X: 6,
},
tEmbed2: tEmbed2{
Y: 7,
Z: 8,
},
}
var want S2
jsonRoundTrip(t, s2, &want)
var got S2
fields, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(got))
if err != nil {
t.Fatal(err)
}
setFields(fields, &got, s2)
if !testutil.Equal(got, want, cmp.AllowUnexported(S2{})) {
t.Errorf("got\n%+v\nwant\n%+v", got, want)
}
}
func TestUnexportedAnonymousNonStruct(t *testing.T) {
// An unexported anonymous non-struct field should not be recorded.
// This is currently a bug in encoding/json.
// https://github.com/golang/go/issues/18009
type (
u int
v int
S struct {
u
v `json:"x"`
int
}
)
got, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(S{}))
if err != nil {
t.Fatal(err)
}
if len(got) != 0 {
t.Errorf("got %d fields, want 0", len(got))
}
}
func TestUnexportedAnonymousStruct(t *testing.T) {
// An unexported anonymous struct with a tag is ignored.
// This is currently a bug in encoding/json.
// https://github.com/golang/go/issues/18009
type (
s1 struct{ X int }
S2 struct {
s1 `json:"Y"`
}
)
got, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(S2{}))
if err != nil {
t.Fatal(err)
}
if len(got) != 0 {
t.Errorf("got %d fields, want 0", len(got))
}
}
func TestDominantField(t *testing.T) {
// With fields sorted by index length and then by tag presence,
// the dominant field is always the first. Make sure all error
// cases are caught.
for _, test := range []struct {
fields []Field
wantOK bool
}{
// A single field is OK.
{[]Field{{Index: []int{0}}}, true},
{[]Field{{Index: []int{0}, NameFromTag: true}}, true},
// A single field at top level is OK.
{[]Field{{Index: []int{0}}, {Index: []int{1, 0}}}, true},
{[]Field{{Index: []int{0}}, {Index: []int{1, 0}, NameFromTag: true}}, true},
{[]Field{{Index: []int{0}, NameFromTag: true}, {Index: []int{1, 0}, NameFromTag: true}}, true},
// A single tagged field is OK.
{[]Field{{Index: []int{0}, NameFromTag: true}, {Index: []int{1}}}, true},
// Two untagged fields at the same level is an error.
{[]Field{{Index: []int{0}}, {Index: []int{1}}}, false},
// Two tagged fields at the same level is an error.
{[]Field{{Index: []int{0}, NameFromTag: true}, {Index: []int{1}, NameFromTag: true}}, false},
} {
_, gotOK := dominantField(test.fields)
if gotOK != test.wantOK {
t.Errorf("%v: got %t, want %t", test.fields, gotOK, test.wantOK)
}
}
}
func TestIgnore(t *testing.T) {
type S struct {
X int `json:"-"`
}
got, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(S{}))
if err != nil {
t.Fatal(err)
}
if len(got) != 0 {
t.Errorf("got %d fields, want 0", len(got))
}
}
func TestParsedTag(t *testing.T) {
type S struct {
X int `json:"name,omitempty"`
}
got, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(S{}))
if err != nil {
t.Fatal(err)
}
want := []*Field{
{Name: "name", NameFromTag: true, Type: intType,
Index: []int{0}, ParsedTag: []string{"omitempty"}},
}
if msg, ok := compareFields(got, want); !ok {
t.Error(msg)
}
}
func TestValidateFunc(t *testing.T) {
type MyInvalidStruct struct {
A string
B []int
}
_, err := NewCache(nil, validateFunc, nil).Fields(reflect.TypeOf(MyInvalidStruct{}))
if err == nil {
t.Fatal("expected error, got nil")
}
type MyValidStruct struct {
A string
B int
}
_, err = NewCache(nil, validateFunc, nil).Fields(reflect.TypeOf(MyValidStruct{}))
if err != nil {
t.Fatalf("expected nil, got error: %s\n", err)
}
}
func compareFields(got []Field, want []*Field) (msg string, ok bool) {
if len(got) != len(want) {
return fmt.Sprintf("got %d fields, want %d", len(got), len(want)), false
}
for i, g := range got {
w := *want[i]
if !fieldsEqual(&g, &w) {
return fmt.Sprintf("got %+v, want %+v", g, w), false
}
}
return "", true
}
// Need this because Field contains a function, which cannot be compared even
// by testutil.Equal.
func fieldsEqual(f1, f2 *Field) bool {
if f1 == nil || f2 == nil {
return f1 == f2
}
return f1.Name == f2.Name &&
f1.NameFromTag == f2.NameFromTag &&
f1.Type == f2.Type &&
testutil.Equal(f1.ParsedTag, f2.ParsedTag)
}
// Set the fields of dst from those of src.
// dst must be a pointer to a struct value.
// src must be a struct value.
func setFields(fields []Field, dst, src interface{}) {
vsrc := reflect.ValueOf(src)
vdst := reflect.ValueOf(dst).Elem()
for _, f := range fields {
fdst := vdst.FieldByIndex(f.Index)
fsrc := vsrc.FieldByIndex(f.Index)
fdst.Set(fsrc)
}
}
func jsonRoundTrip(t *testing.T, in, out interface{}) {
bytes, err := json.Marshal(in)
if err != nil {
t.Fatal(err)
}
if err := json.Unmarshal(bytes, out); err != nil {
t.Fatal(err)
}
}
type S3 struct {
S4
Abc int
AbC int
Tag int
X int `json:"Tag"`
unexported int
}
type S4 struct {
ABc int
Y int `json:"Abc"` // ignored because of top-level Abc
}
func TestMatchingField(t *testing.T) {
fields, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(S3{}))
if err != nil {
t.Fatal(err)
}
for _, test := range []struct {
name string
want *Field
}{
// Exact match wins.
{"Abc", field("Abc", int(0), 1)},
{"AbC", field("AbC", int(0), 2)},
{"ABc", field("ABc", int(0), 0, 0)},
// If there are multiple matches but no exact match or tag,
// the first field wins, lexicographically by index.
// Here, "ABc" is at a deeper embedding level, but since S4 appears
// first in S3, its index precedes the other fields of S3.
{"abc", field("ABc", int(0), 0, 0)},
// Tag name takes precedence over untagged field of the same name.
{"Tag", tfield("Tag", int(0), 4)},
// Unexported fields disappear.
{"unexported", nil},
// Untagged embedded structs disappear.
{"S4", nil},
} {
if got := fields.Match(test.name); !fieldsEqual(got, test.want) {
t.Errorf("match %q:\ngot %+v\nwant %+v", test.name, got, test.want)
}
}
}
func TestAgainstJSONMatchingField(t *testing.T) {
s3 := S3{
S4: S4{ABc: 1, Y: 2},
Abc: 3,
AbC: 4,
Tag: 5,
X: 6,
unexported: 7,
}
var want S3
jsonRoundTrip(t, s3, &want)
v := reflect.ValueOf(want)
fields, err := NewCache(jsonTagParser, nil, nil).Fields(reflect.TypeOf(S3{}))
if err != nil {
t.Fatal(err)
}
for _, test := range []struct {
name string
got int
}{
{"Abc", 3},
{"AbC", 4},
{"ABc", 1},
{"abc", 1},
{"Tag", 6},
} {
f := fields.Match(test.name)
if f == nil {
t.Fatalf("%s: no match", test.name)
}
w := v.FieldByIndex(f.Index).Interface()
if test.got != w {
t.Errorf("%s: got %d, want %d", test.name, test.got, w)
}
}
}
func TestTagErrors(t *testing.T) {
called := false
c := NewCache(func(t reflect.StructTag) (string, bool, interface{}, error) {
called = true
s := t.Get("f")
if s == "bad" {
return "", false, nil, errors.New("error")
}
return s, true, nil, nil
}, nil, nil)
type T struct {
X int `f:"ok"`
Y int `f:"bad"`
}
_, err := c.Fields(reflect.TypeOf(T{}))
if !called {
t.Fatal("tag parser not called")
}
if err == nil {
t.Error("want error, got nil")
}
// Second time, we should cache the error.
called = false
_, err = c.Fields(reflect.TypeOf(T{}))
if called {
t.Fatal("tag parser called on second time")
}
if err == nil {
t.Error("want error, got nil")
}
}