Files
genqlient/generate/testdata/snapshots/TestGenerate-StructOption.graphql-StructOption.graphql.go
T
Ben KraftandGitHub 65c3e20ee6 Fix bugs relating to optional fields with custom (un)marshalers (#116)
## Summary:
There were a few bugs here, one of which Craig came across when pulling
the custom-unmarshaler change into webapp:
1. If you have an optional field with a custom unmarshaler, and the
   server omits the field from the response entirely (i.e. does not
   write `"myField": null`), we would still call your unmarshaler with
   an input of `[]byte(nil)`.  This is just wrong; it's our job to do
   the nil-check.  (This is the one Craig found; in practice gqlgen
   servers do not do this and I think the spec says not to although it's
   a bit fuzzy on the matter of serialization.  But in practice we have
   mocks that do it -- for required fields even! -- and it seems better
   to handle it than pass you data on which you'll probably err or even
   panic.)
2. If you have an optional field with a custom unmarshaler, and the
   server returns an explicit null (i.e. `"myField": null`), we would
   call your unmarshaler with `[]byte("null")`.  In principle the intent
   was you're supposed to implement that, as [`json.Unmarshaler`
   advises][1].  But (a) I forgot to document that, and (b) in practice
   `json.Unmarshal` [does *not* call you in that case][2], i.e. its
   advice is unnecessary.  So I think it's better for us to just match
   it, and not call you.  (And in that case I see no reason to bother
   documenting the advice.)
3. If you have an optional, `pointer: true` field with a custom
   marshaler, the reverse of (2) applies: if the pointer is nil, we
   shouldn't really call you.  (Indeed if you were a real
   `json.Marshaler` with a value-method rather than a pointer-method,
   trying to call you might panic!)  Note we don't need to explicitly
   write "null"; we just leave the `json.RawMessage` as nil, and
   `json.Marshal` [handles that][3].
4. We handle interface types effectively the same as custom
   unmarshalers, just we generate the unmarshaler.  So if you have an
   optional field with interface type, (1) would also apply there; our
   generated unmarshaler returns an error in this case.
5. While (2) doesn't apply to such optional interface fields (because we
   do the customary `if string(b) == "null"` check -- this I at least
   thought to test), if you set `pointer: true` on the field, we would
   still call the unmarshaler on the value, and it would no-op, but only
   *after* we initialized the pointer.  Put more simply, we'd return a
   non-nil pointer to nil interface, rather than a nil pointer; this is
   wrong since the whole point of `pointer: true` is you only get a
   non-nil pointer if your value is nil!  Of course, in practice there's
   little reason to use `pointer: true` on interface fields, and indeed
   this stuff gets so confusing my test was even wrong.

In this commit I fix all the bugs, by adding appropriate nil-checks to
wrap the unmarshaler-calls.  The templates are, as always, a bit
confusing, but the generated code makes it clear what changed.

Note we'll want to land this before cutting a release with custom
marshaler/unmarshaler support, because the first three bugs are
potentially quite noticeable.  (The latter two are in `v0.1.0`, but
presumably quite rare.)

[1]: https://pkg.go.dev/encoding/json#Unmarshaler
[2]: https://play.golang.org/p/Pw6zNN8trGO
[3]: https://play.golang.org/p/crTfnT7ePte

Issue: https://phabricator.khanacademy.org/D74453#inline-558571

## Test plan:
make tesc


Author: benjaminjkraft

Reviewers: csilvers, StevenACoffman, benjaminjkraft, aberkan, dnerdy, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: csilvers, StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/116
2021-09-27 20:35:39 -07:00

307 lines
10 KiB
Go

package test
// Code generated by github.com/Khan/genqlient, DO NOT EDIT.
import (
"encoding/json"
"fmt"
"github.com/Khan/genqlient/graphql"
"github.com/Khan/genqlient/internal/testutil"
)
// Role is a type a user may have.
type Role string
const (
// What is a student?
//
// A student is primarily a person enrolled in a school or other educational institution and who is under learning with goals of acquiring knowledge, developing professions and achieving employment at desired field. In the broader sense, a student is anyone who applies themselves to the intensive intellectual engagement with some matter necessary to master it as part of some practical affair in which such mastery is basic or decisive.
//
// (from [Wikipedia](https://en.wikipedia.org/wiki/Student))
RoleStudent Role = "STUDENT"
// Teacher is a teacher, who teaches the students.
RoleTeacher Role = "TEACHER"
)
// StructOptionResponse is returned by StructOption on success.
type StructOptionResponse struct {
Root StructOptionRootTopic `json:"root"`
// user looks up a user by some stuff.
//
// See UserQueryInput for what stuff is supported.
// If query is null, returns the current user.
User StructOptionUser `json:"user"`
}
// StructOptionRootTopic includes the requested fields of the GraphQL type Topic.
type StructOptionRootTopic struct {
// ID is documented in the Content interface.
Id testutil.ID `json:"id"`
Children []StructOptionRootTopicChildrenContent `json:"children"`
}
// StructOptionRootTopicChildrenContent includes the requested fields of the GraphQL type Content.
// The GraphQL type's documentation follows.
//
// Content is implemented by various types like Article, Video, and Topic.
type StructOptionRootTopicChildrenContent struct {
Typename string `json:"__typename"`
// ID is the identifier of the content.
Id testutil.ID `json:"id"`
Parent StructOptionRootTopicChildrenContentParentTopic `json:"parent"`
}
// StructOptionRootTopicChildrenContentParentTopic includes the requested fields of the GraphQL type Topic.
type StructOptionRootTopicChildrenContentParentTopic struct {
// ID is documented in the Content interface.
Id testutil.ID `json:"id"`
Children []StructOptionRootTopicChildrenContentParentTopicChildrenContent `json:"children"`
InterfaceChildren []StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent `json:"-"`
}
func (v *StructOptionRootTopicChildrenContentParentTopic) UnmarshalJSON(b []byte) error {
if string(b) == "null" {
return nil
}
var firstPass struct {
*StructOptionRootTopicChildrenContentParentTopic
InterfaceChildren []json.RawMessage `json:"interfaceChildren"`
graphql.NoUnmarshalJSON
}
firstPass.StructOptionRootTopicChildrenContentParentTopic = v
err := json.Unmarshal(b, &firstPass)
if err != nil {
return err
}
{
dst := &v.InterfaceChildren
src := firstPass.InterfaceChildren
*dst = make(
[]StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent,
len(src))
for i, src := range src {
dst := &(*dst)[i]
if len(src) != 0 && string(src) != "null" {
err = __unmarshalStructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent(
src, dst)
if err != nil {
return fmt.Errorf(
"Unable to unmarshal StructOptionRootTopicChildrenContentParentTopic.InterfaceChildren: %w", err)
}
}
}
}
return nil
}
// StructOptionRootTopicChildrenContentParentTopicChildrenContent includes the requested fields of the GraphQL type Content.
// The GraphQL type's documentation follows.
//
// Content is implemented by various types like Article, Video, and Topic.
type StructOptionRootTopicChildrenContentParentTopicChildrenContent struct {
Typename string `json:"__typename"`
// ID is the identifier of the content.
Id testutil.ID `json:"id"`
}
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenArticle includes the requested fields of the GraphQL type Article.
type StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenArticle struct {
Typename string `json:"__typename"`
// ID is the identifier of the content.
Id testutil.ID `json:"id"`
}
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent includes the requested fields of the GraphQL interface Content.
//
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent is implemented by the following types:
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenArticle
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenTopic
// The GraphQL type's documentation follows.
//
// Content is implemented by various types like Article, Video, and Topic.
type StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent interface {
implementsGraphQLInterfaceStructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent()
// GetTypename returns the receiver's concrete GraphQL type-name (see interface doc for possible values).
GetTypename() string
// GetId returns the interface-field "id" from its implementation.
// The GraphQL interface field's documentation follows.
//
// ID is the identifier of the content.
GetId() testutil.ID
}
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenArticle) implementsGraphQLInterfaceStructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent() {
}
// GetTypename is a part of, and documented with, the interface StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent.
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenArticle) GetTypename() string {
return v.Typename
}
// GetId is a part of, and documented with, the interface StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent.
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenArticle) GetId() testutil.ID {
return v.Id
}
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo) implementsGraphQLInterfaceStructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent() {
}
// GetTypename is a part of, and documented with, the interface StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent.
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo) GetTypename() string {
return v.Typename
}
// GetId is a part of, and documented with, the interface StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent.
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo) GetId() testutil.ID {
return v.Id
}
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenTopic) implementsGraphQLInterfaceStructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent() {
}
// GetTypename is a part of, and documented with, the interface StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent.
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenTopic) GetTypename() string {
return v.Typename
}
// GetId is a part of, and documented with, the interface StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent.
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenTopic) GetId() testutil.ID {
return v.Id
}
func __unmarshalStructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent(b []byte, v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent) error {
if string(b) == "null" {
return nil
}
var tn struct {
TypeName string `json:"__typename"`
}
err := json.Unmarshal(b, &tn)
if err != nil {
return err
}
switch tn.TypeName {
case "Article":
*v = new(StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenArticle)
return json.Unmarshal(b, *v)
case "Video":
*v = new(StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo)
return json.Unmarshal(b, *v)
case "Topic":
*v = new(StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenTopic)
return json.Unmarshal(b, *v)
case "":
return fmt.Errorf(
"Response was missing Content.__typename")
default:
return fmt.Errorf(
`Unexpected concrete type for StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenContent: "%v"`, tn.TypeName)
}
}
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenTopic includes the requested fields of the GraphQL type Topic.
type StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenTopic struct {
Typename string `json:"__typename"`
// ID is the identifier of the content.
Id testutil.ID `json:"id"`
}
// StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo includes the requested fields of the GraphQL type Video.
type StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo struct {
Typename string `json:"__typename"`
// ID is the identifier of the content.
Id testutil.ID `json:"id"`
VideoFields `json:"-"`
}
func (v *StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo) UnmarshalJSON(b []byte) error {
if string(b) == "null" {
return nil
}
var firstPass struct {
*StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo
graphql.NoUnmarshalJSON
}
firstPass.StructOptionRootTopicChildrenContentParentTopicInterfaceChildrenVideo = v
err := json.Unmarshal(b, &firstPass)
if err != nil {
return err
}
err = json.Unmarshal(
b, &v.VideoFields)
if err != nil {
return err
}
return nil
}
// StructOptionUser includes the requested fields of the GraphQL type User.
// The GraphQL type's documentation follows.
//
// A User is a user!
type StructOptionUser struct {
Roles []Role `json:"roles"`
}
// VideoFields includes the GraphQL fields of Video requested by the fragment VideoFields.
type VideoFields struct {
Duration int `json:"duration"`
}
func StructOption(
client graphql.Client,
) (*StructOptionResponse, error) {
var err error
var retval StructOptionResponse
err = client.MakeRequest(
nil,
"StructOption",
`
query StructOption {
root {
id
children {
__typename
id
parent {
id
children {
__typename
id
}
interfaceChildren: children {
__typename
id
... VideoFields
}
}
}
}
user {
roles
}
}
fragment VideoFields on Video {
duration
}
`,
&retval,
nil,
)
return &retval, err
}