From de3d54cd1eb2d3499cbf2f381b545a8258c3c05f Mon Sep 17 00:00:00 2001
From: Alif Rachmawadi <code@subosito.com>
Date: Thu, 6 Apr 2017 15:39:16 +0700
Subject: [PATCH] Add supports for snake case (#77)

---
 graphql_test.go                        | 116 +++++++++++++++++++++++++
 internal/exec/resolvable/packer.go     |   5 +-
 internal/exec/resolvable/resolvable.go |   6 +-
 3 files changed, 125 insertions(+), 2 deletions(-)

diff --git a/graphql_test.go b/graphql_test.go
index 24d42195bb3..8c1e1422833 100644
--- a/graphql_test.go
+++ b/graphql_test.go
@@ -22,6 +22,26 @@ func (r *helloWorldResolver2) Hello(ctx context.Context) (string, error) {
 	return "Hello world!", nil
 }
 
+type helloSnakeResolver1 struct{}
+
+func (r *helloSnakeResolver1) HelloHTML() string {
+	return "Hello snake!"
+}
+
+func (r *helloSnakeResolver1) SayHello(args *struct{ FullName string }) string {
+	return "Hello " + args.FullName + "!"
+}
+
+type helloSnakeResolver2 struct{}
+
+func (r *helloSnakeResolver2) HelloHTML(ctx context.Context) (string, error) {
+	return "Hello snake!", nil
+}
+
+func (r *helloSnakeResolver2) SayHello(ctx context.Context, args *struct{ FullName string }) (string, error) {
+	return "Hello " + args.FullName + "!", nil
+}
+
 type theNumberResolver struct {
 	number int32
 }
@@ -91,6 +111,102 @@ func TestHelloWorld(t *testing.T) {
 	})
 }
 
+func TestHelloSnake(t *testing.T) {
+	gqltesting.RunTests(t, []*gqltesting.Test{
+		{
+			Schema: graphql.MustParseSchema(`
+				schema {
+					query: Query
+				}
+
+				type Query {
+					hello_html: String!
+				}
+			`, &helloSnakeResolver1{}),
+			Query: `
+				{
+					hello_html
+				}
+			`,
+			ExpectedResult: `
+				{
+					"hello_html": "Hello snake!"
+				}
+			`,
+		},
+
+		{
+			Schema: graphql.MustParseSchema(`
+				schema {
+					query: Query
+				}
+
+				type Query {
+					hello_html: String!
+				}
+			`, &helloSnakeResolver2{}),
+			Query: `
+				{
+					hello_html
+				}
+			`,
+			ExpectedResult: `
+				{
+					"hello_html": "Hello snake!"
+				}
+			`,
+		},
+	})
+}
+
+func TestHelloSnakeArguments(t *testing.T) {
+	gqltesting.RunTests(t, []*gqltesting.Test{
+		{
+			Schema: graphql.MustParseSchema(`
+				schema {
+					query: Query
+				}
+
+				type Query {
+					say_hello(full_name: String!): String!
+				}
+			`, &helloSnakeResolver1{}),
+			Query: `
+				{
+					say_hello(full_name: "Rob Pike")
+				}
+			`,
+			ExpectedResult: `
+				{
+					"say_hello": "Hello Rob Pike!"
+				}
+			`,
+		},
+
+		{
+			Schema: graphql.MustParseSchema(`
+				schema {
+					query: Query
+				}
+
+				type Query {
+					say_hello(full_name: String!): String!
+				}
+			`, &helloSnakeResolver2{}),
+			Query: `
+				{
+					say_hello(full_name: "Rob Pike")
+				}
+			`,
+			ExpectedResult: `
+				{
+					"say_hello": "Hello Rob Pike!"
+				}
+			`,
+		},
+	})
+}
+
 func TestBasic(t *testing.T) {
 	gqltesting.RunTests(t, []*gqltesting.Test{
 		{
diff --git a/internal/exec/resolvable/packer.go b/internal/exec/resolvable/packer.go
index 105d1894572..c21d672b081 100644
--- a/internal/exec/resolvable/packer.go
+++ b/internal/exec/resolvable/packer.go
@@ -130,8 +130,11 @@ func (b *execBuilder) makeStructPacker(values common.InputValueList, typ reflect
 	var fields []*structPackerField
 	for _, v := range values {
 		fe := &structPackerField{field: v}
+		fx := func(n string) bool {
+			return strings.EqualFold(stripUnderscore(n), stripUnderscore(v.Name.Name))
+		}
 
-		sf, ok := structType.FieldByNameFunc(func(n string) bool { return strings.EqualFold(n, v.Name.Name) })
+		sf, ok := structType.FieldByNameFunc(fx)
 		if !ok {
 			return nil, fmt.Errorf("missing argument %q", v.Name)
 		}
diff --git a/internal/exec/resolvable/resolvable.go b/internal/exec/resolvable/resolvable.go
index 63d1dfde78d..23298a93cf4 100644
--- a/internal/exec/resolvable/resolvable.go
+++ b/internal/exec/resolvable/resolvable.go
@@ -333,7 +333,7 @@ func (b *execBuilder) makeFieldExec(typeName string, f *schema.Field, m reflect.
 
 func findMethod(t reflect.Type, name string) int {
 	for i := 0; i < t.NumMethod(); i++ {
-		if strings.EqualFold(name, t.Method(i).Name) {
+		if strings.EqualFold(stripUnderscore(name), stripUnderscore(t.Method(i).Name)) {
 			return i
 		}
 	}
@@ -346,3 +346,7 @@ func unwrapNonNull(t common.Type) (common.Type, bool) {
 	}
 	return t, false
 }
+
+func stripUnderscore(s string) string {
+	return strings.Replace(s, "_", "", -1)
+}