feat: add support for graphql fragments

core/core.go

@@ -196,8 +196,6 @@ func (c *scontext) resolvePreparedSQL() ([]byte, *stmt, error) {
 		return nil, nil, err
 	}
 
-	fmt.Println(">>", varsList)
-
 	if useTx {
 		row = tx.Stmt(q.sd).QueryRow(varsList...)
 	} else {

core/internal/psql/query_test.go

@@ -307,6 +307,80 @@ func multiRoot(t *testing.T) {
 	compileGQLToPSQL(t, gql, nil, "user")
 }
 
+func withFragment1(t *testing.T) {
+	gql := `
+	fragment userFields1 on user {
+		id
+		email
+	}
+
+	query {
+		users {
+			...userFields2
+	
+			created_at
+			...userFields1
+		}
+	}
+	
+	fragment userFields2 on user {
+		first_name
+		last_name
+	}`
+
+	compileGQLToPSQL(t, gql, nil, "anon")
+}
+
+func withFragment2(t *testing.T) {
+	gql := `
+	query {
+		users {
+			...userFields2
+	
+			created_at
+			...userFields1
+		}
+	}
+
+	fragment userFields1 on user {
+		id
+		email
+	}
+	
+	fragment userFields2 on user {
+		first_name
+		last_name
+	}`
+
+	compileGQLToPSQL(t, gql, nil, "anon")
+}
+
+func withFragment3(t *testing.T) {
+	gql := `
+
+	fragment userFields1 on user {
+		id
+		email
+	}
+	
+	fragment userFields2 on user {
+		first_name
+		last_name
+	}
+
+	query {
+		users {
+			...userFields2
+	
+			created_at
+			...userFields1
+		}
+	}
+`
+
+	compileGQLToPSQL(t, gql, nil, "anon")
+}
+
 func withCursor(t *testing.T) {
 	gql := `query {
 		Products(
@@ -400,6 +474,9 @@ func TestCompileQuery(t *testing.T) {
 	t.Run("queryWithVariables", queryWithVariables)
 	t.Run("withWhereOnRelations", withWhereOnRelations)
 	t.Run("multiRoot", multiRoot)
+	t.Run("withFragment1", withFragment1)
+	t.Run("withFragment2", withFragment2)
+	t.Run("withFragment3", withFragment3)
 	t.Run("jsonColumnAsTable", jsonColumnAsTable)
 	t.Run("withCursor", withCursor)
 	t.Run("nullForAuthRequiredInAnon", nullForAuthRequiredInAnon)

core/internal/psql/tests.sql

@@ -86,6 +86,12 @@ SELECT jsonb_build_object('product', "__sj_0"."json") as "__root" FROM (SELECT t
 SELECT jsonb_build_object('users', "__sj_0"."json") as "__root" FROM (SELECT coalesce(jsonb_agg("__sj_0"."json"), '[]') as "json" FROM (SELECT to_jsonb("__sr_0".*) AS "json"FROM (SELECT "users_0"."id" AS "id", "users_0"."email" AS "email" FROM (SELECT "users"."id", "users"."email" FROM "users" WHERE (NOT EXISTS (SELECT 1 FROM products WHERE (("products"."user_id") = ("users"."id")) AND ((("products"."price") > '3' :: numeric(7,2))))) LIMIT ('20') :: integer) AS "users_0") AS "__sr_0") AS "__sj_0") AS "__sj_0"
 === RUN   TestCompileQuery/multiRoot
 SELECT jsonb_build_object('customer', "__sj_0"."json", 'user', "__sj_1"."json", 'product', "__sj_2"."json") as "__root" FROM (SELECT to_jsonb("__sr_2".*) AS "json"FROM (SELECT "products_2"."id" AS "id", "products_2"."name" AS "name", "__sj_3"."json" AS "customers", "__sj_4"."json" AS "customer" FROM (SELECT "products"."id", "products"."name" FROM "products" WHERE (((("products"."price") > '0' :: numeric(7,2)) AND (("products"."price") < '8' :: numeric(7,2)))) LIMIT ('1') :: integer) AS "products_2" LEFT OUTER JOIN LATERAL (SELECT to_jsonb("__sr_4".*) AS "json"FROM (SELECT "customers_4"."email" AS "email" FROM (SELECT "customers"."email" FROM "customers" LEFT OUTER JOIN "purchases" ON (("purchases"."product_id") = ("products_2"."id")) WHERE ((("customers"."id") = ("purchases"."customer_id"))) LIMIT ('1') :: integer) AS "customers_4") AS "__sr_4") AS "__sj_4" ON ('true') LEFT OUTER JOIN LATERAL (SELECT coalesce(jsonb_agg("__sj_3"."json"), '[]') as "json" FROM (SELECT to_jsonb("__sr_3".*) AS "json"FROM (SELECT "customers_3"."email" AS "email" FROM (SELECT "customers"."email" FROM "customers" LEFT OUTER JOIN "purchases" ON (("purchases"."product_id") = ("products_2"."id")) WHERE ((("customers"."id") = ("purchases"."customer_id"))) LIMIT ('20') :: integer) AS "customers_3") AS "__sr_3") AS "__sj_3") AS "__sj_3" ON ('true')) AS "__sr_2") AS "__sj_2", (SELECT to_jsonb("__sr_1".*) AS "json"FROM (SELECT "users_1"."id" AS "id", "users_1"."email" AS "email" FROM (SELECT "users"."id", "users"."email" FROM "users" LIMIT ('1') :: integer) AS "users_1") AS "__sr_1") AS "__sj_1", (SELECT to_jsonb("__sr_0".*) AS "json"FROM (SELECT "customers_0"."id" AS "id" FROM (SELECT "customers"."id" FROM "customers" LIMIT ('1') :: integer) AS "customers_0") AS "__sr_0") AS "__sj_0"
+=== RUN   TestCompileQuery/withFragment1
+SELECT jsonb_build_object('users', "__sj_0"."json") as "__root" FROM (SELECT coalesce(jsonb_agg("__sj_0"."json"), '[]') as "json" FROM (SELECT to_jsonb("__sr_0".*) AS "json"FROM (SELECT "users_0"."first_name" AS "first_name", "users_0"."last_name" AS "last_name", "users_0"."created_at" AS "created_at", "users_0"."id" AS "id", "users_0"."email" AS "email" FROM (SELECT , "users"."created_at", "users"."id", "users"."email" FROM "users" GROUP BY "users"."created_at", "users"."id", "users"."email" LIMIT ('20') :: integer) AS "users_0") AS "__sr_0") AS "__sj_0") AS "__sj_0"
+=== RUN   TestCompileQuery/withFragment2
+SELECT jsonb_build_object('users', "__sj_0"."json") as "__root" FROM (SELECT coalesce(jsonb_agg("__sj_0"."json"), '[]') as "json" FROM (SELECT to_jsonb("__sr_0".*) AS "json"FROM (SELECT "users_0"."first_name" AS "first_name", "users_0"."last_name" AS "last_name", "users_0"."created_at" AS "created_at", "users_0"."id" AS "id", "users_0"."email" AS "email" FROM (SELECT , "users"."created_at", "users"."id", "users"."email" FROM "users" GROUP BY "users"."created_at", "users"."id", "users"."email" LIMIT ('20') :: integer) AS "users_0") AS "__sr_0") AS "__sj_0") AS "__sj_0"
+=== RUN   TestCompileQuery/withFragment3
+SELECT jsonb_build_object('users', "__sj_0"."json") as "__root" FROM (SELECT coalesce(jsonb_agg("__sj_0"."json"), '[]') as "json" FROM (SELECT to_jsonb("__sr_0".*) AS "json"FROM (SELECT "users_0"."first_name" AS "first_name", "users_0"."last_name" AS "last_name", "users_0"."created_at" AS "created_at", "users_0"."id" AS "id", "users_0"."email" AS "email" FROM (SELECT , "users"."created_at", "users"."id", "users"."email" FROM "users" GROUP BY "users"."created_at", "users"."id", "users"."email" LIMIT ('20') :: integer) AS "users_0") AS "__sr_0") AS "__sj_0") AS "__sj_0"
 === RUN   TestCompileQuery/jsonColumnAsTable
 SELECT jsonb_build_object('products', "__sj_0"."json") as "__root" FROM (SELECT coalesce(jsonb_agg("__sj_0"."json"), '[]') as "json" FROM (SELECT to_jsonb("__sr_0".*) AS "json"FROM (SELECT "products_0"."id" AS "id", "products_0"."name" AS "name", "__sj_1"."json" AS "tag_count" FROM (SELECT "products"."id", "products"."name" FROM "products" LIMIT ('20') :: integer) AS "products_0" LEFT OUTER JOIN LATERAL (SELECT to_jsonb("__sr_1".*) AS "json"FROM (SELECT "tag_count_1"."count" AS "count", "__sj_2"."json" AS "tags" FROM (SELECT "tag_count"."count", "tag_count"."tag_id" FROM "products", json_to_recordset("products"."tag_count") AS "tag_count"(tag_id bigint, count int) WHERE ((("products"."id") = ("products_0"."id"))) LIMIT ('1') :: integer) AS "tag_count_1" LEFT OUTER JOIN LATERAL (SELECT coalesce(jsonb_agg("__sj_2"."json"), '[]') as "json" FROM (SELECT to_jsonb("__sr_2".*) AS "json"FROM (SELECT "tags_2"."name" AS "name" FROM (SELECT "tags"."name" FROM "tags" WHERE ((("tags"."id") = ("tag_count_1"."tag_id"))) LIMIT ('20') :: integer) AS "tags_2") AS "__sr_2") AS "__sj_2") AS "__sj_2" ON ('true')) AS "__sr_1") AS "__sj_1" ON ('true')) AS "__sr_0") AS "__sj_0") AS "__sj_0"
 === RUN   TestCompileQuery/withCursor
@@ -117,6 +123,9 @@ SELECT jsonb_build_object('users', "__sj_0"."json") as "__root" FROM (SELECT coa
     --- PASS: TestCompileQuery/queryWithVariables (0.00s)
     --- PASS: TestCompileQuery/withWhereOnRelations (0.00s)
     --- PASS: TestCompileQuery/multiRoot (0.00s)
+    --- PASS: TestCompileQuery/withFragment1 (0.00s)
+    --- PASS: TestCompileQuery/withFragment2 (0.00s)
+    --- PASS: TestCompileQuery/withFragment3 (0.00s)
     --- PASS: TestCompileQuery/jsonColumnAsTable (0.00s)
     --- PASS: TestCompileQuery/withCursor (0.00s)
     --- PASS: TestCompileQuery/nullForAuthRequiredInAnon (0.00s)
@@ -151,4 +160,4 @@ WITH "_sg_input" AS (SELECT $1 :: json AS j), "_x_users" AS (SELECT * FROM (VALU
     --- PASS: TestCompileUpdate/nestedUpdateOneToOneWithConnect (0.00s)
     --- PASS: TestCompileUpdate/nestedUpdateOneToOneWithDisconnect (0.00s)
 PASS
-ok  	github.com/dosco/super-graph/core/internal/psql	(cached)
+ok  	github.com/dosco/super-graph/core/internal/psql	0.374s

core/internal/qcode/lex.go

@@ -11,15 +11,18 @@ import (
 var (
 	queryToken        = []byte("query")
 	mutationToken     = []byte("mutation")
+	fragmentToken     = []byte("fragment")
 	subscriptionToken = []byte("subscription")
+	onToken           = []byte("on")
 	trueToken         = []byte("true")
 	falseToken        = []byte("false")
 	quotesToken       = []byte(`'"`)
 	signsToken        = []byte(`+-`)
-	punctuatorToken   = []byte(`!():=[]{|}`)
 	spreadToken       = []byte(`...`)
 	digitToken        = []byte(`0123456789`)
 	dotToken          = []byte(`.`)
+
+	punctuatorToken = `!():=[]{|}`
 )
 
 // Pos represents a byte position in the original input text from which
@@ -43,6 +46,8 @@ const (
 	itemName
 	itemQuery
 	itemMutation
+	itemFragment
+	itemOn
 	itemSub
 	itemPunctuator
 	itemArgsOpen
@@ -263,12 +268,12 @@ func lexRoot(l *lexer) stateFn {
 		l.backup()
 		return lexString
 	case r == '.':
-		if len(l.input) >= 3 {
+		l.acceptRun(dotToken)
-			if equals(l.input, 0, 3, spreadToken) {
+		s, e := l.current()
+		if equals(l.input, s, e, spreadToken) {
 			l.emit(itemSpread)
 			return lexRoot
 		}
-		}
 		fallthrough // '.' can start a number.
 	case r == '+' || r == '-' || ('0' <= r && r <= '9'):
 		l.backup()
@@ -299,10 +304,14 @@ func lexName(l *lexer) stateFn {
 			switch {
 			case equals(l.input, s, e, queryToken):
 				l.emitL(itemQuery)
+			case equals(l.input, s, e, fragmentToken):
+				l.emitL(itemFragment)
 			case equals(l.input, s, e, mutationToken):
 				l.emitL(itemMutation)
 			case equals(l.input, s, e, subscriptionToken):
 				l.emitL(itemSub)
+			case equals(l.input, s, e, onToken):
+				l.emitL(itemOn)
 			case equals(l.input, s, e, trueToken):
 				l.emitL(itemBoolVal)
 			case equals(l.input, s, e, falseToken):
@@ -396,31 +405,11 @@ func isAlphaNumeric(r rune) bool {
 }
 
 func equals(b []byte, s Pos, e Pos, val []byte) bool {
-	n := 0
+	return bytes.EqualFold(b[s:e], val)
-	for i := s; i < e; i++ {
-		if n >= len(val) {
-			return true
-		}
-		switch {
-		case b[i] >= 'A' && b[i] <= 'Z' && ('a'+(b[i]-'A')) != val[n]:
-			return false
-		case b[i] != val[n]:
-			return false
-		}
-		n++
-	}
-	return true
 }
 
-func contains(b []byte, s Pos, e Pos, val []byte) bool {
+func contains(b []byte, s Pos, e Pos, chars string) bool {
-	for i := s; i < e; i++ {
+	return bytes.ContainsAny(b[s:e], chars)
-		for n := 0; n < len(val); n++ {
-			if b[i] == val[n] {
-				return true
-			}
-		}
-	}
-	return false
 }
 
 func lowercase(b []byte, s Pos, e Pos) {

core/internal/qcode/parse.go

@@ -3,10 +3,9 @@ package qcode
 import (
 	"errors"
 	"fmt"
+	"hash/maphash"
 	"sync"
 	"unsafe"
-
-	"github.com/dosco/super-graph/core/internal/util"
 )
 
 var (
@@ -35,8 +34,7 @@ const (
 	NodeVar
 )
 
-type Operation struct {
+type SelectionSet struct {
-	Type    parserType
 	Name    string
 	Args    []Arg
 	argsA   [10]Arg
@@ -44,12 +42,29 @@ type Operation struct {
 	fieldsA [10]Field
 }
 
+type Operation struct {
+	Type parserType
+	SelectionSet
+}
+
 var zeroOperation = Operation{}
 
 func (o *Operation) Reset() {
 	*o = zeroOperation
 }
 
+type Fragment struct {
+	Name string
+	On   string
+	SelectionSet
+}
+
+var zeroFragment = Fragment{}
+
+func (f *Fragment) Reset() {
+	*f = zeroFragment
+}
+
 type Field struct {
 	ID        int32
 	ParentID  int32
@@ -82,6 +97,8 @@ func (n *Node) Reset() {
 }
 
 type Parser struct {
+	frags map[uint64]*Fragment
+	h     maphash.Hash
 	input []byte // the string being scanned
 	pos   int
 	items []item
@@ -96,12 +113,194 @@ var opPool = sync.Pool{
 	New: func() interface{} { return new(Operation) },
 }
 
+var fragPool = sync.Pool{
+	New: func() interface{} { return new(Fragment) },
+}
+
 var lexPool = sync.Pool{
 	New: func() interface{} { return new(lexer) },
 }
 
 func Parse(gql []byte) (*Operation, error) {
-	return parseSelectionSet(gql)
+	var err error
+
+	if len(gql) == 0 {
+		return nil, errors.New("blank query")
+	}
+
+	l := lexPool.Get().(*lexer)
+	l.Reset()
+	defer lexPool.Put(l)
+
+	if err = lex(l, gql); err != nil {
+		return nil, err
+	}
+
+	p := &Parser{
+		input: l.input,
+		pos:   -1,
+		items: l.items,
+	}
+
+	op := opPool.Get().(*Operation)
+	op.Reset()
+	op.Fields = op.fieldsA[:0]
+
+	s := -1
+	qf := false
+
+	for {
+		if p.peek(itemEOF) {
+			p.ignore()
+			break
+		}
+
+		if p.peek(itemFragment) {
+			p.ignore()
+			if err = p.parseFragment(op); err != nil {
+				return nil, err
+			}
+		} else {
+			if !qf && p.peek(itemQuery, itemMutation, itemSub, itemObjOpen) {
+				s = p.pos
+				qf = true
+			}
+			p.ignore()
+		}
+	}
+
+	p.reset(s)
+	if err := p.parseOp(op); err != nil {
+		return nil, err
+	}
+
+	return op, nil
+}
+
+func (p *Parser) parseFragment(op *Operation) error {
+	frag := fragPool.Get().(*Fragment)
+	frag.Reset()
+
+	frag.Fields = frag.fieldsA[:0]
+	frag.Args = frag.argsA[:0]
+
+	if p.peek(itemName) {
+		frag.Name = p.val(p.next())
+	}
+
+	if p.peek(itemOn) {
+		p.ignore()
+	} else {
+		return errors.New("fragment: missing 'on' keyword")
+	}
+
+	if p.peek(itemName) {
+		frag.On = p.vall(p.next())
+	} else {
+		return errors.New("fragment: missing table name after 'on' keyword")
+	}
+
+	if p.peek(itemObjOpen) {
+		p.ignore()
+	} else {
+		return fmt.Errorf("fragment: expecting a '{', got: %s", p.next())
+	}
+
+	if err := p.parseSelectionSet(&frag.SelectionSet); err != nil {
+		return fmt.Errorf("fragment: %v", err)
+	}
+
+	if p.frags == nil {
+		p.frags = make(map[uint64]*Fragment)
+	}
+
+	_, _ = p.h.WriteString(frag.Name)
+	k := p.h.Sum64()
+	p.h.Reset()
+
+	p.frags[k] = frag
+
+	return nil
+}
+
+func (p *Parser) parseOp(op *Operation) error {
+	var err error
+	var typeSet bool
+
+	if p.peek(itemQuery, itemMutation, itemSub) {
+		err = p.parseOpTypeAndArgs(op)
+
+		if err != nil {
+			return fmt.Errorf("%s: %v", op.Type, err)
+		}
+		typeSet = true
+	}
+
+	if p.peek(itemObjOpen) {
+		p.ignore()
+		if !typeSet {
+			op.Type = opQuery
+		}
+
+		for {
+			if p.peek(itemEOF, itemFragment) {
+				p.ignore()
+				break
+			}
+
+			err = p.parseSelectionSet(&op.SelectionSet)
+			if err != nil {
+				return fmt.Errorf("%s: %v", op.Type, err)
+			}
+		}
+	} else {
+		return fmt.Errorf("expecting a query, mutation or subscription, got: %s", p.next())
+	}
+
+	return nil
+}
+
+func (p *Parser) parseOpTypeAndArgs(op *Operation) error {
+	item := p.next()
+
+	switch item._type {
+	case itemQuery:
+		op.Type = opQuery
+	case itemMutation:
+		op.Type = opMutate
+	case itemSub:
+		op.Type = opSub
+	}
+
+	op.Args = op.argsA[:0]
+
+	var err error
+
+	if p.peek(itemName) {
+		op.Name = p.val(p.next())
+	}
+
+	if p.peek(itemArgsOpen) {
+		p.ignore()
+
+		op.Args, err = p.parseOpParams(op.Args)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (p *Parser) parseSelectionSet(selset *SelectionSet) error {
+	var err error
+
+	selset.Fields, err = p.parseFields(selset.Fields)
+	if err != nil {
+		return err
+	}
+
+	return nil
 }
 
 func ParseArgValue(argVal string) (*Node, error) {
@@ -123,216 +322,107 @@ func ParseArgValue(argVal string) (*Node, error) {
 	return op, err
 }
 
-func parseSelectionSet(gql []byte) (*Operation, error) {
+func (p *Parser) parseFields(fields []Field) ([]Field, error) {
-	var err error
+	st := NewStack()
 
-	if len(gql) == 0 {
+	if !p.peek(itemName, itemSpread) {
-		return nil, errors.New("blank query")
+		return nil, fmt.Errorf("unexpected token: %s", p.peekNext())
 	}
 
-	l := lexPool.Get().(*lexer)
+	for {
-	l.Reset()
+		if p.peek(itemEOF) {
-
-	if err = lex(l, gql); err != nil {
-		return nil, err
-	}
-
-	p := &Parser{
-		input: l.input,
-		pos:   -1,
-		items: l.items,
-	}
-
-	var op *Operation
-
-	if p.peek(itemObjOpen) {
 			p.ignore()
-		op, err = p.parseQueryOp()
+			return nil, errors.New("invalid query")
-	} else {
-		op, err = p.parseOp()
-	}
-
-	if err != nil {
-		return nil, err
 		}
 
 		if p.peek(itemObjClose) {
 			p.ignore()
+
+			if st.Len() != 0 {
+				st.Pop()
+				continue
 			} else {
-		return nil, fmt.Errorf("operation missing closing '}'")
-	}
-
-	if !p.peek(itemEOF) {
-		p.ignore()
-		return nil, fmt.Errorf("invalid '%s' found after closing '}'", p.current())
-	}
-
-	lexPool.Put(l)
-
-	return op, err
-}
-
-func (p *Parser) next() item {
-	n := p.pos + 1
-	if n >= len(p.items) {
-		p.err = errEOT
-		return item{_type: itemEOF}
-	}
-	p.pos = n
-	return p.items[p.pos]
-}
-
-func (p *Parser) ignore() {
-	n := p.pos + 1
-	if n >= len(p.items) {
-		p.err = errEOT
-		return
-	}
-	p.pos = n
-}
-
-func (p *Parser) current() string {
-	item := p.items[p.pos]
-	return b2s(p.input[item.pos:item.end])
-}
-
-func (p *Parser) peek(types ...itemType) bool {
-	n := p.pos + 1
-	// if p.items[n]._type == itemEOF {
-	// 	return false
-	// }
-
-	if n >= len(p.items) {
-		return false
-	}
-	for i := 0; i < len(types); i++ {
-		if p.items[n]._type == types[i] {
-			return true
-		}
-	}
-	return false
-}
-
-func (p *Parser) parseOp() (*Operation, error) {
-	if !p.peek(itemQuery, itemMutation, itemSub) {
-		err := errors.New("expecting a query, mutation or subscription")
-		return nil, err
-	}
-	item := p.next()
-
-	op := opPool.Get().(*Operation)
-	op.Reset()
-
-	switch item._type {
-	case itemQuery:
-		op.Type = opQuery
-	case itemMutation:
-		op.Type = opMutate
-	case itemSub:
-		op.Type = opSub
-	}
-
-	op.Fields = op.fieldsA[:0]
-	op.Args = op.argsA[:0]
-
-	var err error
-
-	if p.peek(itemName) {
-		op.Name = p.val(p.next())
-	}
-
-	if p.peek(itemArgsOpen) {
-		p.ignore()
-
-		op.Args, err = p.parseOpParams(op.Args)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	if p.peek(itemObjOpen) {
-		p.ignore()
-
-		for n := 0; n < 10; n++ {
-			if !p.peek(itemName) {
 				break
 			}
-
-			op.Fields, err = p.parseFields(op.Fields)
-			if err != nil {
-				return nil, err
-			}
-		}
 		}
 
-	return op, nil
-}
-
-func (p *Parser) parseQueryOp() (*Operation, error) {
-	op := opPool.Get().(*Operation)
-	op.Reset()
-
-	op.Type = opQuery
-	op.Fields = op.fieldsA[:0]
-	op.Args = op.argsA[:0]
-
-	var err error
-
-	for n := 0; n < 10; n++ {
-		if !p.peek(itemName) {
-			break
-		}
-
-		op.Fields, err = p.parseFields(op.Fields)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return op, nil
-}
-
-func (p *Parser) parseFields(fields []Field) ([]Field, error) {
-	st := util.NewStack()
-
-	for {
 		if len(fields) >= maxFields {
 			return nil, fmt.Errorf("too many fields (max %d)", maxFields)
 		}
 
-		if p.peek(itemEOF, itemObjClose) {
+		isFrag := false
-			p.ignore()
-			st.Pop()
 
-			if st.Len() == 0 {
+		if p.peek(itemSpread) {
-				break
+			p.ignore()
-			} else {
+			isFrag = true
-				continue
-			}
 		}
 
 		if !p.peek(itemName) {
-			return nil, errors.New("expecting an alias or field name")
+			if isFrag {
+				return nil, fmt.Errorf("expecting a fragment name, got: %s", p.next())
+			} else {
+				return nil, fmt.Errorf("expecting an alias or field name, got: %s", p.next())
+			}
 		}
 
+		var f *Field
+
+		if isFrag {
+			name := p.val(p.next())
+			p.h.WriteString(name)
+			k := p.h.Sum64()
+			p.h.Reset()
+
+			fr, ok := p.frags[k]
+			if !ok {
+				return nil, fmt.Errorf("no fragment named '%s' defined", name)
+			}
+
+			n := int32(len(fields))
+			fields = append(fields, fr.Fields...)
+
+			for i := int(n); i < len(fields); i++ {
+				f := &fields[i]
+				f.ID = int32(i)
+
+				// If this is the top-level point the parent to the parent of the
+				// previous field.
+				if f.ParentID == -1 {
+					pid := st.Peek()
+					f.ParentID = pid
+					if f.ParentID != -1 {
+						fields[pid].Children = append(fields[f.ParentID].Children, f.ID)
+					}
+					// Update all the other parents id's by our new place in this new array
+				} else {
+					f.ParentID += n
+				}
+
+				// Update all the children which is needed.
+				for j := range f.Children {
+					f.Children[j] += n
+				}
+			}
+
+		} else {
 			fields = append(fields, Field{ID: int32(len(fields))})
 
-		f := &fields[(len(fields) - 1)]
+			f = &fields[(len(fields) - 1)]
 			f.Args = f.argsA[:0]
 			f.Children = f.childrenA[:0]
 
-		// Parse the inside of the the fields () parentheses
+			// Parse the field
-		// in short parse the args like id, where, etc
 			if err := p.parseField(f); err != nil {
 				return nil, err
 			}
 
-		intf := st.Peek()
+			if st.Len() == 0 {
-		if pid, ok := intf.(int32); ok {
+				f.ParentID = -1
+			} else {
+				pid := st.Peek()
 				f.ParentID = pid
 				fields[pid].Children = append(fields[pid].Children, f.ID)
-		} else {
+			}
-			f.ParentID = -1
 		}
 
 		// The first opening curley brackets after this
@@ -340,13 +430,6 @@ func (p *Parser) parseFields(fields []Field) ([]Field, error) {
 		if p.peek(itemObjOpen) {
 			p.ignore()
 			st.Push(f.ID)
-
-		} else if p.peek(itemObjClose) {
-			if st.Len() == 0 {
-				break
-			} else {
-				continue
-			}
 		}
 	}
 
@@ -546,6 +629,62 @@ func (p *Parser) vall(v item) string {
 	return b2s(p.input[v.pos:v.end])
 }
 
+func (p *Parser) peek(types ...itemType) bool {
+	n := p.pos + 1
+	l := len(types)
+	// if p.items[n]._type == itemEOF {
+	// 	return false
+	// }
+
+	if n >= len(p.items) {
+		return types[0] == itemEOF
+	}
+
+	if l == 1 {
+		return p.items[n]._type == types[0]
+	}
+
+	for i := 0; i < l; i++ {
+		if p.items[n]._type == types[i] {
+			return true
+		}
+	}
+	return false
+}
+
+func (p *Parser) next() item {
+	n := p.pos + 1
+	if n >= len(p.items) {
+		p.err = errEOT
+		return item{_type: itemEOF}
+	}
+	p.pos = n
+	return p.items[p.pos]
+}
+
+func (p *Parser) ignore() {
+	n := p.pos + 1
+	if n >= len(p.items) {
+		p.err = errEOT
+		return
+	}
+	p.pos = n
+}
+
+func (p *Parser) peekCurrent() string {
+	item := p.items[p.pos]
+	return b2s(p.input[item.pos:item.end])
+}
+
+func (p *Parser) peekNext() string {
+	item := p.items[p.pos+1]
+	return b2s(p.input[item.pos:item.end])
+}
+
+func (p *Parser) reset(to int) {
+	p.pos = to
+}
+
 func b2s(b []byte) string {
 	return *(*string)(unsafe.Pointer(&b))
 }
@@ -579,7 +718,7 @@ func (t parserType) String() string {
 	case NodeList:
 		v = "node-list"
 	}
-	return fmt.Sprintf("<%s>", v)
+	return v
 }
 
 // type Frees struct {

core/internal/qcode/parse_test.go

@@ -121,7 +121,7 @@ updateThread {
     }
 	}
 }
-}`
+}}`
 	qcompile, _ := NewCompiler(Config{})
 	_, err := qcompile.Compile([]byte(gql), "anon")
 
@@ -131,19 +131,90 @@ updateThread {
 
 }
 
-func TestFragmentsCompile(t *testing.T) {
+func TestFragmentsCompile1(t *testing.T) {
 	gql := `
-fragment userFields on user {
+	fragment userFields1 on user {
-  name
+		id
 		email
+	}
+
+	query {
+		users {
+			...userFields2
+	
+			created_at
+			...userFields1
+		}
+	}
+	
+	fragment userFields2 on user {
+		first_name
+		last_name
+	}
+	`
+	qcompile, _ := NewCompiler(Config{})
+	_, err := qcompile.Compile([]byte(gql), "user")
+
+	if err != nil {
+		t.Fatal(err)
+	}
 }
 
-query { users { ...userFields } }`
+func TestFragmentsCompile2(t *testing.T) {
-	qcompile, _ := NewCompiler(Config{})
+	gql := `
-	_, err := qcompile.Compile([]byte(gql), "anon")
+	query {
+		users {
+			...userFields2
 	
-	if err == nil {
+			created_at
-		t.Fatal(errors.New("expecting an error"))
+			...userFields1
+		}
+	}
+
+	fragment userFields1 on user {
+		id
+		email
+	}
+	
+	fragment userFields2 on user {
+		first_name
+		last_name
+	}`
+	qcompile, _ := NewCompiler(Config{})
+	_, err := qcompile.Compile([]byte(gql), "user")
+
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestFragmentsCompile3(t *testing.T) {
+	gql := `
+	fragment userFields1 on user {
+		id
+		email
+	}
+	
+	fragment userFields2 on user {
+		first_name
+		last_name
+	}
+
+	query {
+		users {
+			...userFields2
+	
+			created_at
+			...userFields1
+		}
+	}
+
+	`
+	qcompile, _ := NewCompiler(Config{})
+	_, err := qcompile.Compile([]byte(gql), "user")
+
+	if err != nil {
+		t.Fatal(err)
 	}
 }
 
@@ -201,7 +272,6 @@ func BenchmarkQCompileP(b *testing.B) {
 }
 
 func BenchmarkParse(b *testing.B) {
-
 	b.ResetTimer()
 	b.ReportAllocs()
 	for n := 0; n < b.N; n++ {