star wars example: friendsConnection

example/starwars/starwars.go

@@ -3,7 +3,12 @@
 // Source: https://github.com/graphql/graphql.github.io/blob/source/site/_core/swapiSchema.js
 package starwars
 
-import "strings"
+import (
+	"encoding/base64"
+	"fmt"
+	"strconv"
+	"strings"
+)
 
 var Schema = `
 	schema {
@@ -343,7 +348,7 @@ type characterResolver interface {
 	ID() string
 	Name() string
 	Friends() *[]characterResolver
-	FriendsConnection(friendsConenctionArgs) *friendsConnectionResolver
+	FriendsConnection(friendsConenctionArgs) (*friendsConnectionResolver, error)
 	AppearsIn() []string
 	ToHuman() (*humanResolver, bool)
 	ToDroid() (*droidResolver, bool)
@@ -377,8 +382,8 @@ func (r *humanResolver) Friends() *[]characterResolver {
 	return resolveCharacters(r.h.Friends)
 }
 
-func (r *humanResolver) FriendsConnection(args friendsConenctionArgs) *friendsConnectionResolver {
-	panic("TODO")
+func (r *humanResolver) FriendsConnection(args friendsConenctionArgs) (*friendsConnectionResolver, error) {
+	return newFriendsConnectionResolver(r.h.Friends, args)
 }
 
 func (r *humanResolver) AppearsIn() []string {
@@ -421,8 +426,8 @@ func (r *droidResolver) Friends() *[]characterResolver {
 	return resolveCharacters(r.d.Friends)
 }
 
-func (r *droidResolver) FriendsConnection(args friendsConenctionArgs) *friendsConnectionResolver {
-	panic("TODO")
+func (r *droidResolver) FriendsConnection(args friendsConenctionArgs) (*friendsConnectionResolver, error) {
+	return newFriendsConnectionResolver(r.d.Friends, args)
 }
 
 func (r *droidResolver) AppearsIn() []string {
@@ -496,16 +501,23 @@ func convertLength(meters float64, unit string) float64 {
 func resolveCharacters(ids []string) *[]characterResolver {
 	var characters []characterResolver
 	for _, id := range ids {
-		if h, ok := humanData[id]; ok {
-			characters = append(characters, &humanResolver{h})
-		}
-		if d, ok := droidData[id]; ok {
-			characters = append(characters, &droidResolver{d})
+		if c := resolveCharacter(id); c != nil {
+			characters = append(characters, c)
 		}
 	}
 	return &characters
 }
 
+func resolveCharacter(id string) characterResolver {
+	if h, ok := humanData[id]; ok {
+		return &humanResolver{h}
+	}
+	if d, ok := droidData[id]; ok {
+		return &droidResolver{d}
+	}
+	return nil
+}
+
 type reviewResolver struct {
 }
 
@@ -518,46 +530,98 @@ func (r *reviewResolver) Commentary() *string {
 }
 
 type friendsConnectionResolver struct {
+	ids  []string
+	from int
+	to   int
+}
+
+func newFriendsConnectionResolver(ids []string, args friendsConenctionArgs) (*friendsConnectionResolver, error) {
+	from := 0
+	if args.After != "" {
+		b, err := base64.StdEncoding.DecodeString(args.After)
+		if err != nil {
+			return nil, err
+		}
+		i, err := strconv.Atoi(strings.TrimPrefix(string(b), "cursor"))
+		if err != nil {
+			return nil, err
+		}
+		from = i
+	}
+
+	to := len(ids)
+	if args.First != 0 {
+		to = from + int(args.First)
+	}
+	if to > len(ids)-from {
+		to = len(ids) - from
+	}
+
+	return &friendsConnectionResolver{
+		ids:  ids,
+		from: from,
+		to:   to,
+	}, nil
 }
 
 func (r *friendsConnectionResolver) TotalCount() int32 {
-	panic("TODO")
+	return int32(len(r.ids))
 }
 
 func (r *friendsConnectionResolver) Edges() *[]*friendsEdgeResolver {
-	panic("TODO")
+	l := make([]*friendsEdgeResolver, r.to-r.from)
+	for i := range l {
+		l[i] = &friendsEdgeResolver{
+			cursor: encodeCursor(r.from + i),
+			id:     r.ids[r.from+i],
+		}
+	}
+	return &l
 }
 
 func (r *friendsConnectionResolver) Friends() *[]characterResolver {
-	panic("TODO")
+	return resolveCharacters(r.ids[r.from:r.to])
 }
 
 func (r *friendsConnectionResolver) PageInfo() *pageInfoResolver {
-	panic("TODO")
+	return &pageInfoResolver{
+		startCursor: encodeCursor(r.from),
+		endCursor:   encodeCursor(r.to - 1),
+		hasNextPage: r.to < len(r.ids),
+	}
+}
+
+func encodeCursor(i int) string {
+	return base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("cursor%d", i+1)))
 }
 
 type friendsEdgeResolver struct {
+	cursor string
+	id     string
 }
 
 func (r *friendsEdgeResolver) Cursor() string {
-	panic("TODO")
+	return r.cursor
 }
 
 func (r *friendsEdgeResolver) Node() characterResolver {
-	panic("TODO")
+	return resolveCharacter(r.id)
 }
 
 type pageInfoResolver struct {
+	startCursor string
+	endCursor   string
+	hasNextPage bool
 }
 
 func (r *pageInfoResolver) StartCursor() *string {
-	panic("TODO")
+	return &r.startCursor
 }
 
 func (r *pageInfoResolver) EndCursor() *string {
-	panic("TODO")
+	return &r.endCursor
 }
 
 func (r *pageInfoResolver) HasNextPage() bool {
-	panic("TODO")
+	return r.hasNextPage
 }

graphql_test.go

@@ -543,6 +543,118 @@ var tests = []struct {
 		`,
 	},
 
+	{
+		name:     "StarWarsConnections1",
+		schema:   starwars.Schema,
+		resolver: &starwars.Resolver{},
+		query: `
+			{
+				hero {
+					name
+					friendsConnection {
+						totalCount
+            pageInfo {
+              startCursor
+              endCursor
+              hasNextPage
+            }
+            edges {
+              cursor
+              node {
+                name
+              }
+            }
+					}
+				}
+			}
+		`,
+		result: `
+			{
+				"hero": {
+					"name": "R2-D2",
+					"friendsConnection": {
+						"totalCount": 3,
+						"pageInfo": {
+							"startCursor": "Y3Vyc29yMQ==",
+							"endCursor": "Y3Vyc29yMw==",
+							"hasNextPage": false
+						},
+						"edges": [
+							{
+								"cursor": "Y3Vyc29yMQ==",
+								"node": {
+									"name": "Luke Skywalker"
+								}
+							},
+							{
+								"cursor": "Y3Vyc29yMg==",
+								"node": {
+									"name": "Han Solo"
+								}
+							},
+							{
+								"cursor": "Y3Vyc29yMw==",
+								"node": {
+									"name": "Leia Organa"
+								}
+							}
+						]
+					}
+				}
+			}
+		`,
+	},
+
+	{
+		name:     "StarWarsConnections2",
+		schema:   starwars.Schema,
+		resolver: &starwars.Resolver{},
+		query: `
+			{
+				hero {
+					name
+					friendsConnection(first: 1, after: "Y3Vyc29yMQ==") {
+						totalCount
+            pageInfo {
+              startCursor
+              endCursor
+              hasNextPage
+            }
+            edges {
+              cursor
+              node {
+                name
+              }
+            }
+					}
+				}
+			}
+		`,
+		result: `
+			{
+				"hero": {
+					"name": "R2-D2",
+					"friendsConnection": {
+						"totalCount": 3,
+						"pageInfo": {
+							"startCursor": "Y3Vyc29yMg==",
+							"endCursor": "Y3Vyc29yMg==",
+							"hasNextPage": true
+						},
+						"edges": [
+							{
+								"cursor": "Y3Vyc29yMg==",
+								"node": {
+									"name": "Han Solo"
+								}
+							}
+						]
+					}
+				}
+			}
+		`,
+	},
+
 	{
 		name:     "StarWarsIntrospection1",
 		schema:   starwars.Schema,
@@ -845,6 +957,10 @@ func TestAll(t *testing.T) {
 				t.Fatal(err)
 			}
 
+			if len(result.Errors) != 0 {
+				t.Fatal(result.Errors[0])
+			}
+
 			got, err := json.Marshal(result.Data)
 			if err != nil {
 				t.Fatal(err)

internal/exec/exec.go

@@ -233,8 +233,6 @@ func makeFieldExecs(s *schema.Schema, typeName string, fields map[string]*schema
 			return nil, fmt.Errorf("method %q of %s has too many return values", m.Name, resolverType)
 		}
 
-		// TODO type check result
-
 		hasError := m.Type.NumOut() == 2
 		if hasError {
 			if m.Type.Out(1) != errorType {

internal/query/query.go

@@ -221,7 +221,6 @@ func parseArguments(l *lexer.Lexer) map[string]Value {
 		name, value := parseArgument(l)
 		args[name] = value
 		for l.Peek() != ')' {
-			l.ConsumeToken(',')
 			name, value := parseArgument(l)
 			args[name] = value
 		}