feat: support graphql.object_type.squash_union option

packages/@testapis/proto/src/testapis/extensions/extensions.proto

@@ -32,6 +32,19 @@ message PrefixedMessage {
     string body = 1;
   }
 
+  message InnerMessage2 {
+    string body = 1;
+  }
+
+  message SquashedMessage {
+    option (graphql.object_type).squash_union = true;
+
+    oneof squashed_message {
+      InnerMessage oneof_ignored_field = 1;
+      InnerMessage2 oneof_ignored_field_2 = 2;
+    }
+  }
+
   // Output only.
   uint64 id = 1;
   string body = 2;
@@ -49,6 +62,7 @@ message PrefixedMessage {
   OutputOnlyMessage output_only_message = 8;
   InputOnlyMessage input_only_message = 9;
   IgnoredEnum ignored_enum = 10;
+  SquashedMessage squashed_message = 11;
 }
 
 enum PrefixedEnum {

packages/protoc-gen-nexus/include/graphql/schema.proto

@@ -16,6 +16,22 @@ extend google.protobuf.FileOptions {
 
 message GraphqlObjectTypeOptions {
   bool ignore = 1;
+  // If `squash_union` is true, the message is converted to `union` type.
+  //
+  // ```proto
+  // message Content {
+  //   option (graphql.object_type).squash_union = true;
+  //   oneof content {
+  //     Blog blog = 2;
+  //     Video video = 2;
+  //   }
+  // }
+  // ```
+  //
+  // ```grahpql
+  // union Content = Blog | Video
+  // ```
+  bool squash_union = 2;
 }
 
 message GraphqlInputObjectTypeOptions {

packages/protoc-gen-nexus/src/__tests__/__integration__/__snapshots__/customOptions.test.ts.snap

@@ -1,5 +1,121 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`schema generation with native protobuf can make GraphQL schema from generated DSLs: schema.graphql 1`] = `
+"### This file was generated by Nexus Schema
+### Do not make changes to this file directly
+
+
+type Query {
+  ok: Boolean!
+}
+
+\\"\\"\\"\\"\\"\\"
+input TestPrefixInputOnlyMessageInput {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+
+  \\"\\"\\"\\"\\"\\"
+  prefixedEnum: TestPrefixPrefixedEnum
+}
+
+\\"\\"\\"\\"\\"\\"
+type TestPrefixOutputOnlyMessage {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+
+  \\"\\"\\"\\"\\"\\"
+  prefixedEnum: TestPrefixPrefixedEnum
+}
+
+\\"\\"\\"\\"\\"\\"
+enum TestPrefixPrefixedEnum {
+  PREFIXED_BAR
+  PREFIXED_FOO
+}
+
+\\"\\"\\"\\"\\"\\"
+type TestPrefixPrefixedMessage {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+
+  \\"\\"\\"Output only.\\"\\"\\"
+  id: String!
+
+  \\"\\"\\"\\"\\"\\"
+  outputOnlyMessage: TestPrefixOutputOnlyMessage
+
+  \\"\\"\\"\\"\\"\\"
+  prefixedEnum: TestPrefixPrefixedEnum
+
+  \\"\\"\\"\\"\\"\\"
+  squashedMessage: TestPrefixPrefixedMessageSquashedMessage
+}
+
+\\"\\"\\"\\"\\"\\"
+type TestPrefixPrefixedMessageInnerMessage {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+}
+
+\\"\\"\\"\\"\\"\\"
+type TestPrefixPrefixedMessageInnerMessage2 {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+}
+
+\\"\\"\\"\\"\\"\\"
+input TestPrefixPrefixedMessageInnerMessage2Input {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+}
+
+\\"\\"\\"\\"\\"\\"
+input TestPrefixPrefixedMessageInnerMessageInput {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+}
+
+\\"\\"\\"\\"\\"\\"
+input TestPrefixPrefixedMessageInput {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+
+  \\"\\"\\"\\"\\"\\"
+  inputOnlyMessage: TestPrefixInputOnlyMessageInput
+
+  \\"\\"\\"\\"\\"\\"
+  prefixedEnum: TestPrefixPrefixedEnum
+
+  \\"\\"\\"\\"\\"\\"
+  squashedMessage: TestPrefixPrefixedMessageSquashedMessageInput
+}
+
+\\"\\"\\"\\"\\"\\"
+union TestPrefixPrefixedMessageSquashedMessage = TestPrefixPrefixedMessageInnerMessage | TestPrefixPrefixedMessageInnerMessage2
+
+\\"\\"\\"\\"\\"\\"
+input TestPrefixPrefixedMessageSquashedMessageInput {
+  \\"\\"\\"\\"\\"\\"
+  oneofIgnoredField: TestPrefixPrefixedMessageInnerMessageInput
+
+  \\"\\"\\"\\"\\"\\"
+  oneofIgnoredField2: TestPrefixPrefixedMessageInnerMessage2Input
+}
+"
+`;
+
+exports[`schema generation with native protobuf squashed union 1`] = `
+Object {
+  "data": Object {
+    "test": Object {
+      "squashedMessage": Object {
+        "body": "field 2",
+      },
+    },
+  },
+}
+`;
+
 exports[`schema generation with protobufjs can make GraphQL schema from generated DSLs: schema.graphql 1`] = `
 "### This file was generated by Nexus Schema
 ### Do not make changes to this file directly
@@ -46,6 +162,9 @@ type TestPrefixPrefixedMessage {
 
   \\"\\"\\"\\"\\"\\"
   prefixedEnum: TestPrefixPrefixedEnum
+
+  \\"\\"\\"\\"\\"\\"
+  squashedMessage: TestPrefixPrefixedMessageSquashedMessage
 }
 
 \\"\\"\\"\\"\\"\\"
@@ -54,6 +173,18 @@ type TestPrefixPrefixedMessageInnerMessage {
   body: String!
 }
 
+\\"\\"\\"\\"\\"\\"
+type TestPrefixPrefixedMessageInnerMessage2 {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+}
+
+\\"\\"\\"\\"\\"\\"
+input TestPrefixPrefixedMessageInnerMessage2Input {
+  \\"\\"\\"\\"\\"\\"
+  body: String!
+}
+
 \\"\\"\\"\\"\\"\\"
 input TestPrefixPrefixedMessageInnerMessageInput {
   \\"\\"\\"\\"\\"\\"
@@ -70,6 +201,33 @@ input TestPrefixPrefixedMessageInput {
 
   \\"\\"\\"\\"\\"\\"
   prefixedEnum: TestPrefixPrefixedEnum
+
+  \\"\\"\\"\\"\\"\\"
+  squashedMessage: TestPrefixPrefixedMessageSquashedMessageInput
+}
+
+\\"\\"\\"\\"\\"\\"
+union TestPrefixPrefixedMessageSquashedMessage = TestPrefixPrefixedMessageInnerMessage | TestPrefixPrefixedMessageInnerMessage2
+
+\\"\\"\\"\\"\\"\\"
+input TestPrefixPrefixedMessageSquashedMessageInput {
+  \\"\\"\\"\\"\\"\\"
+  oneofIgnoredField: TestPrefixPrefixedMessageInnerMessageInput
+
+  \\"\\"\\"\\"\\"\\"
+  oneofIgnoredField2: TestPrefixPrefixedMessageInnerMessage2Input
 }
 "
 `;
+
+exports[`schema generation with protobufjs squashed union 1`] = `
+Object {
+  "data": Object {
+    "test": Object {
+      "squashedMessage": Object {
+        "body": "field 2",
+      },
+    },
+  },
+}
+`;