fix: issues caught by fuzzer

core/internal/psql/fuzz.go

@@ -11,7 +11,7 @@ import (
 var (
 	qcompileTest, _ = qcode.NewCompiler(qcode.Config{})
 
-	schema = GetTestSchema()
+	schema, _ = GetTestSchema()
 
 	vars = map[string]string{
 		"admin_account_id": "5",
@@ -25,6 +25,37 @@ var (
 
 // FuzzerEntrypoint for Fuzzbuzz
 func Fuzz(data []byte) int {
+	err1 := query(data)
+	err2 := insert(data)
+	err3 := update(data)
+	err4 := delete(data)
+
+	if err1 != nil || err2 != nil || err3 != nil || err4 != nil {
+		return 0
+	}
+
+	return 1
+}
+
+func query(data []byte) error {
+	gql := data
+
+	qc, err1 := qcompileTest.Compile(gql, "user")
+
+	vars := map[string]json.RawMessage{
+		"data": json.RawMessage(data),
+	}
+
+	_, _, err2 := pcompileTest.CompileEx(qc, vars)
+
+	if err1 != nil {
+		return err1
+	} else {
+		return err2
+	}
+}
+
+func insert(data []byte) error {
 	gql := `mutation {
 		product(insert: $data) {
 			id
@@ -47,9 +78,57 @@ func Fuzz(data []byte) int {
 	}
 
 	_, _, err = pcompileTest.CompileEx(qc, vars)
+	return err
+}
+
+func update(data []byte) error {
+	gql := `mutation {
+		product(insert: $data) {
+			id
+			name
+			user {
+				id
+				full_name
+				email
+			}
+		}
+	}`
+
+	qc, err := qcompileTest.Compile([]byte(gql), "user")
 	if err != nil {
-		return 0
+		panic("qcompile can't fail")
 	}
 
-	return 1
+	vars := map[string]json.RawMessage{
+		"data": json.RawMessage(data),
+	}
+
+	_, _, err = pcompileTest.CompileEx(qc, vars)
+	return err
+}
+
+func delete(data []byte) error {
+	gql := `mutation {
+		product(insert: $data) {
+			id
+			name
+			user {
+				id
+				full_name
+				email
+			}
+		}
+	}`
+
+	qc, err := qcompileTest.Compile([]byte(gql), "user")
+	if err != nil {
+		panic("qcompile can't fail")
+	}
+
+	vars := map[string]json.RawMessage{
+		"data": json.RawMessage(data),
+	}
+
+	_, _, err = pcompileTest.CompileEx(qc, vars)
+	return err
 }

core/internal/psql/fuzz_test.go

@@ -0,0 +1,20 @@
+// +build gofuzz
+
+package psql
+
+import (
+	"testing"
+)
+
+var ret int
+
+func TestFuzzCrashers(t *testing.T) {
+	var crashers = []string{
+		"{\"connect\":{}}",
+		"q(q{q{q{q{q{q{q{q{",
+	}
+
+	for _, f := range crashers {
+		ret = Fuzz([]byte(f))
+	}
+}

core/internal/psql/mutate.go

@@ -542,6 +542,10 @@ func (c *compilerContext) renderConnectStmt(qc *qcode.QCode, w io.Writer,
 
 	rel := item.relPC
 
+	if rel == nil {
+		return errors.New("invalid connect value")
+	}
+
 	// Render only for parent-to-child relationship of one-to-one
 	// For this to work the child needs to found first so it's primary key
 	// can be set in the related column on the parent object.

core/internal/psql/query.go

@@ -80,6 +80,10 @@ func (co *Compiler) CompileEx(qc *qcode.QCode, vars Variables) (Metadata, []byte
 }
 
 func (co *Compiler) Compile(w io.Writer, qc *qcode.QCode, vars Variables) (Metadata, error) {
+	if qc == nil {
+		return Metadata{}, fmt.Errorf("qcode is nil")
+	}
+
 	switch qc.Type {
 	case qcode.QTQuery:
 		return co.compileQuery(w, qc, vars)
@@ -1353,8 +1357,6 @@ func squoted(w io.Writer, identifier string) {
 	io.WriteString(w, `'`)
 }
 
-const charset = "0123456789"
-
 func int32String(w io.Writer, val int32) {
 	io.WriteString(w, strconv.FormatInt(int64(val), 10))
 }