From 3df64dfb8203c33d937593157f6000cd7961312d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Veiga?= <joao.veiga@northvolt.com>
Date: Sat, 11 Dec 2021 20:41:24 +0100
Subject: [PATCH] add fuzzing for schema.Exec, schema and query parsing

---
 graphql_test.go                | 26 ++++++++++++++++++++++++++
 internal/query/query_test.go   | 12 ++++++++++++
 internal/schema/schema_test.go |  7 +++++++
 3 files changed, 45 insertions(+)
 create mode 100644 internal/query/query_test.go

diff --git a/graphql_test.go b/graphql_test.go
index b2074275c..cb326644c 100644
--- a/graphql_test.go
+++ b/graphql_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -4297,3 +4298,28 @@ func TestInterfaceImplementingInterface(t *testing.T) {
 			`,
 	}})
 }
+
+type query struct{}
+
+func (_ *query) Hello() string { return "Hello, world!" }
+func (_ *query) Hi(string, string) string { return "Hello, world!" }
+func (_ *query) LaunchMissil(string, string) string { return "Hello, world!" }
+
+func FuzzSchemaExec(f *testing.F) {
+    f.Fuzz(func(t *testing.T, s string, queryString , operationName string) {
+	    defer func(){
+		    if err := recover(); err != nil{
+			    if !strings.Contains(err.(error).Error(), "invalid syntax"){
+				    panic(err)
+			    }
+		    }
+	    }()
+	    ctx := context.Background()
+	    variables := map[string]interface{}{}
+	    schema,err := graphql.ParseSchema(s, &query{})
+	    if err != nil {
+		    t.Skip()
+	    }
+	    schema.Exec(ctx, queryString, operationName, variables)
+    })
+}
diff --git a/internal/query/query_test.go b/internal/query/query_test.go
new file mode 100644
index 000000000..62e3537df
--- /dev/null
+++ b/internal/query/query_test.go
@@ -0,0 +1,12 @@
+package query
+
+import (
+	"testing"
+)
+
+func FuzzParseQuery(f *testing.F) {
+    f.Fuzz(func(t *testing.T, queryStr string) {
+        Parse(queryStr)
+    })
+}
+
diff --git a/internal/schema/schema_test.go b/internal/schema/schema_test.go
index 065e9917a..e66798f38 100644
--- a/internal/schema/schema_test.go
+++ b/internal/schema/schema_test.go
@@ -1007,3 +1007,10 @@ func TestInterfaceImplementsInterface(t *testing.T) {
 		})
 	}
 }
+
+func FuzzParse(f *testing.F){
+	f.Fuzz(func(t *testing.T, schemaString string, useStringDescriptions bool){
+		s := schema.New()
+		schema.Parse(s, schemaString, useStringDescriptions)
+	})
+}