Add support for inline fragments (#65)

## Summary: In this commit I add support for inline fragments (`... on MyType { fields }`) to genqlient. This will make interfaces a lot more useful! In future commits I'll add named fragments, for which we'll generate slightly different types, as discussed in DESIGN.md. In general, implementing the flattening approach described in DESIGN.md was... surprisingly easy. All we have to do is recurse on applicable fragments when generating our selection-set. The refactor to selection-set handling this encouraged was, I think, quite beneficial. It did reveal two tricky pre-existing issues. One issue is that GraphQL allows for duplicate selections, as long as they match. (In practice, this is only useful in the context of fragments, although GraphQL allows it even without.) I decided to handle the simple case (duplicate leaf fields; we just deduplicate) but leave to the future the complex cases where we need to merge different sub-selections (now #64). For now we just forbid that; we can see how much it comes up. The other issue is that we are generating type-names incorrectly for interface types; I had intended to do `MyInterfaceMyFieldMyType` for shared fields and `MyImplMyFieldMyType` for non-shared ones, but instead I did `MyFieldMyType`, which is inconsistent already and can result in conflicts in the presence of fragments. I'm going to fix this in a separate commit, though, because it's going to require some refactoring and is irrelevant to the main logic of this commit; I left some TODOs in the tests related to this. Issue: https://github.com/Khan/genqlient/issues/8 ## Test plan: make check Author: benjaminjkraft Reviewers: dnerdy, aberkan, MiguelCastillo Required Reviewers: Approved by: dnerdy Checks: ⌛ Test (1.17), ⌛ Test (1.16), ⌛ Test (1.15), ⌛ Test (1.14), ⌛ Test (1.13), ✅ Lint, ⌛ Test (1.17), ⌛ Test (1.16), ⌛ Test (1.15), ⌛ Test (1.14), ⌛ Test (1.13), ✅ Lint Pull request URL: https://github.com/Khan/genqlient/pull/65
2021-08-27 18:06:30 -07:00
parent e99dced757
commit e6b1984d44
19 changed files with 2270 additions and 66 deletions
@@ -10,6 +10,253 @@ import (
 	"github.com/Khan/genqlient/graphql"
 )

+type Species string
+
+const (
+	SpeciesDog        Species = "DOG"
+	SpeciesCoelacanth Species = "COELACANTH"
+)
+
+// queryWithFragmentsBeingsAnimal includes the requested fields of the GraphQL type Animal.
+type queryWithFragmentsBeingsAnimal struct {
+	Typename string                             `json:"__typename"`
+	Id       string                             `json:"id"`
+	Name     string                             `json:"name"`
+	Hair     queryWithFragmentsBeingsHair       `json:"hair"`
+	Species  Species                            `json:"species"`
+	Owner    queryWithFragmentsBeingsOwnerBeing `json:"-"`
+}
+
+func (v *queryWithFragmentsBeingsAnimal) UnmarshalJSON(b []byte) error {
+
+	type queryWithFragmentsBeingsAnimalWrapper queryWithFragmentsBeingsAnimal
+
+	var firstPass struct {
+		*queryWithFragmentsBeingsAnimalWrapper
+		Owner json.RawMessage `json:"owner"`
+	}
+	firstPass.queryWithFragmentsBeingsAnimalWrapper = (*queryWithFragmentsBeingsAnimalWrapper)(v)
+
+	err := json.Unmarshal(b, &firstPass)
+	if err != nil {
+		return err
+	}
+
+	{
+		target := &v.Owner
+		raw := firstPass.Owner
+		err = __unmarshalqueryWithFragmentsBeingsOwnerBeing(
+			target, raw)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// queryWithFragmentsBeingsBeing includes the requested fields of the GraphQL interface Being.
+//
+// queryWithFragmentsBeingsBeing is implemented by the following types:
+// queryWithFragmentsBeingsUser
+// queryWithFragmentsBeingsAnimal
+//
+// The GraphQL type's documentation follows.
+//
+//
+type queryWithFragmentsBeingsBeing interface {
+	implementsGraphQLInterfacequeryWithFragmentsBeingsBeing()
+	// 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.
+	GetId() string
+	// GetName returns the interface-field "name" from its implementation.
+	GetName() string
+}
+
+func (v *queryWithFragmentsBeingsUser) implementsGraphQLInterfacequeryWithFragmentsBeingsBeing() {}
+
+// GetTypename is a part of, and documented with, the interface queryWithFragmentsBeingsBeing.
+func (v *queryWithFragmentsBeingsUser) GetTypename() string { return v.Typename }
+
+// GetId is a part of, and documented with, the interface queryWithFragmentsBeingsBeing.
+func (v *queryWithFragmentsBeingsUser) GetId() string { return v.Id }
+
+// GetName is a part of, and documented with, the interface queryWithFragmentsBeingsBeing.
+func (v *queryWithFragmentsBeingsUser) GetName() string { return v.Name }
+
+func (v *queryWithFragmentsBeingsAnimal) implementsGraphQLInterfacequeryWithFragmentsBeingsBeing() {}
+
+// GetTypename is a part of, and documented with, the interface queryWithFragmentsBeingsBeing.
+func (v *queryWithFragmentsBeingsAnimal) GetTypename() string { return v.Typename }
+
+// GetId is a part of, and documented with, the interface queryWithFragmentsBeingsBeing.
+func (v *queryWithFragmentsBeingsAnimal) GetId() string { return v.Id }
+
+// GetName is a part of, and documented with, the interface queryWithFragmentsBeingsBeing.
+func (v *queryWithFragmentsBeingsAnimal) GetName() string { return v.Name }
+
+func __unmarshalqueryWithFragmentsBeingsBeing(v *queryWithFragmentsBeingsBeing, m json.RawMessage) error {
+	if string(m) == "null" {
+		return nil
+	}
+
+	var tn struct {
+		TypeName string `json:"__typename"`
+	}
+	err := json.Unmarshal(m, &tn)
+	if err != nil {
+		return err
+	}
+
+	switch tn.TypeName {
+	case "User":
+		*v = new(queryWithFragmentsBeingsUser)
+		return json.Unmarshal(m, *v)
+	case "Animal":
+		*v = new(queryWithFragmentsBeingsAnimal)
+		return json.Unmarshal(m, *v)
+	default:
+		return fmt.Errorf(
+			`Unexpected concrete type for queryWithFragmentsBeingsBeing: "%v"`, tn.TypeName)
+	}
+}
+
+// queryWithFragmentsBeingsHair includes the requested fields of the GraphQL type BeingsHair.
+type queryWithFragmentsBeingsHair struct {
+	HasHair bool `json:"hasHair"`
+}
+
+// queryWithFragmentsBeingsOwnerAnimal includes the requested fields of the GraphQL type Animal.
+type queryWithFragmentsBeingsOwnerAnimal struct {
+	Typename string `json:"__typename"`
+	Id       string `json:"id"`
+	Name     string `json:"name"`
+}
+
+// queryWithFragmentsBeingsOwnerBeing includes the requested fields of the GraphQL interface Being.
+//
+// queryWithFragmentsBeingsOwnerBeing is implemented by the following types:
+// queryWithFragmentsBeingsOwnerUser
+// queryWithFragmentsBeingsOwnerAnimal
+//
+// The GraphQL type's documentation follows.
+//
+//
+type queryWithFragmentsBeingsOwnerBeing interface {
+	implementsGraphQLInterfacequeryWithFragmentsBeingsOwnerBeing()
+	// 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.
+	GetId() string
+	// GetName returns the interface-field "name" from its implementation.
+	GetName() string
+}
+
+func (v *queryWithFragmentsBeingsOwnerUser) implementsGraphQLInterfacequeryWithFragmentsBeingsOwnerBeing() {
+}
+
+// GetTypename is a part of, and documented with, the interface queryWithFragmentsBeingsOwnerBeing.
+func (v *queryWithFragmentsBeingsOwnerUser) GetTypename() string { return v.Typename }
+
+// GetId is a part of, and documented with, the interface queryWithFragmentsBeingsOwnerBeing.
+func (v *queryWithFragmentsBeingsOwnerUser) GetId() string { return v.Id }
+
+// GetName is a part of, and documented with, the interface queryWithFragmentsBeingsOwnerBeing.
+func (v *queryWithFragmentsBeingsOwnerUser) GetName() string { return v.Name }
+
+func (v *queryWithFragmentsBeingsOwnerAnimal) implementsGraphQLInterfacequeryWithFragmentsBeingsOwnerBeing() {
+}
+
+// GetTypename is a part of, and documented with, the interface queryWithFragmentsBeingsOwnerBeing.
+func (v *queryWithFragmentsBeingsOwnerAnimal) GetTypename() string { return v.Typename }
+
+// GetId is a part of, and documented with, the interface queryWithFragmentsBeingsOwnerBeing.
+func (v *queryWithFragmentsBeingsOwnerAnimal) GetId() string { return v.Id }
+
+// GetName is a part of, and documented with, the interface queryWithFragmentsBeingsOwnerBeing.
+func (v *queryWithFragmentsBeingsOwnerAnimal) GetName() string { return v.Name }
+
+func __unmarshalqueryWithFragmentsBeingsOwnerBeing(v *queryWithFragmentsBeingsOwnerBeing, m json.RawMessage) error {
+	if string(m) == "null" {
+		return nil
+	}
+
+	var tn struct {
+		TypeName string `json:"__typename"`
+	}
+	err := json.Unmarshal(m, &tn)
+	if err != nil {
+		return err
+	}
+
+	switch tn.TypeName {
+	case "User":
+		*v = new(queryWithFragmentsBeingsOwnerUser)
+		return json.Unmarshal(m, *v)
+	case "Animal":
+		*v = new(queryWithFragmentsBeingsOwnerAnimal)
+		return json.Unmarshal(m, *v)
+	default:
+		return fmt.Errorf(
+			`Unexpected concrete type for queryWithFragmentsBeingsOwnerBeing: "%v"`, tn.TypeName)
+	}
+}
+
+// queryWithFragmentsBeingsOwnerUser includes the requested fields of the GraphQL type User.
+type queryWithFragmentsBeingsOwnerUser struct {
+	Typename    string `json:"__typename"`
+	Id          string `json:"id"`
+	Name        string `json:"name"`
+	LuckyNumber int    `json:"luckyNumber"`
+}
+
+// queryWithFragmentsBeingsUser includes the requested fields of the GraphQL type User.
+type queryWithFragmentsBeingsUser struct {
+	Typename    string                       `json:"__typename"`
+	Id          string                       `json:"id"`
+	Name        string                       `json:"name"`
+	LuckyNumber int                          `json:"luckyNumber"`
+	Hair        queryWithFragmentsBeingsHair `json:"hair"`
+}
+
+// queryWithFragmentsResponse is returned by queryWithFragments on success.
+type queryWithFragmentsResponse struct {
+	Beings []queryWithFragmentsBeingsBeing `json:"-"`
+}
+
+func (v *queryWithFragmentsResponse) UnmarshalJSON(b []byte) error {
+
+	type queryWithFragmentsResponseWrapper queryWithFragmentsResponse
+
+	var firstPass struct {
+		*queryWithFragmentsResponseWrapper
+		Beings []json.RawMessage `json:"beings"`
+	}
+	firstPass.queryWithFragmentsResponseWrapper = (*queryWithFragmentsResponseWrapper)(v)
+
+	err := json.Unmarshal(b, &firstPass)
+	if err != nil {
+		return err
+	}
+
+	{
+		target := &v.Beings
+		raw := firstPass.Beings
+		*target = make(
+			[]queryWithFragmentsBeingsBeing,
+			len(raw))
+		for i, raw := range raw {
+			target := &(*target)[i]
+			err = __unmarshalqueryWithFragmentsBeingsBeing(
+				target, raw)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 // queryWithInterfaceListFieldBeingsAnimal includes the requested fields of the GraphQL type Animal.
 type queryWithInterfaceListFieldBeingsAnimal struct {
 	Typename string `json:"__typename"`
@@ -537,3 +784,59 @@ query queryWithInterfaceListPointerField ($ids: [ID!]!) {
 	)
 	return &retval, err
 }
+
+func queryWithFragments(
+	ctx context.Context,
+	client graphql.Client,
+	ids []string,
+) (*queryWithFragmentsResponse, error) {
+	variables := map[string]interface{}{
+		"ids": ids,
+	}
+
+	var retval queryWithFragmentsResponse
+	err := client.MakeRequest(
+		ctx,
+		"queryWithFragments",
+		`
+query queryWithFragments ($ids: [ID!]!) {
+	beings(ids: $ids) {
+		__typename
+		id
+		... on Being {
+			id
+			name
+		}
+		... on Animal {
+			id
+			hair {
+				hasHair
+			}
+			species
+			owner {
+				__typename
+				id
+				... on Being {
+					name
+				}
+				... on User {
+					luckyNumber
+				}
+			}
+		}
+		... on Lucky {
+			luckyNumber
+		}
+		... on User {
+			hair {
+				color
+			}
+		}
+	}
+}
+`,
+		&retval,
+		variables,
+	)
+	return &retval, err
+}