fix(openapiv2): exclude oneof fields from required with proto3 field semantics

Makefile

@@ -147,6 +147,9 @@ proto:
 	buf generate \
 		--template examples/internal/proto/examplepb/enum_with_single_value.buf.gen.yaml \
 		--path examples/internal/proto/examplepb/enum_with_single_value.proto
+	buf generate \
+		--template ./examples/internal/proto/examplepb/proto3_field_semantics.buf.gen.yaml \
+		--path examples/internal/proto/examplepb/proto3_field_semantics.proto
 	buf generate \
 		--template ./protoc-gen-openapiv2/options/buf.gen.yaml \
 		--path ./protoc-gen-openapiv2/options/annotations.proto \

buf.yaml

@@ -22,6 +22,7 @@ lint:
       - examples/internal/proto/examplepb/opaque.proto
       - examples/internal/proto/examplepb/openapi_merge_a.proto
       - examples/internal/proto/examplepb/openapi_merge_b.proto
+      - examples/internal/proto/examplepb/proto3_field_semantics.proto
       - examples/internal/proto/examplepb/response_body_service.proto
       - examples/internal/proto/examplepb/stream.proto
       - examples/internal/proto/examplepb/unannotated_echo_service.proto
@@ -68,6 +69,7 @@ lint:
       - examples/internal/proto/examplepb/opaque.proto
       - examples/internal/proto/examplepb/openapi_merge_a.proto
       - examples/internal/proto/examplepb/openapi_merge_b.proto
+      - examples/internal/proto/examplepb/proto3_field_semantics.proto
       - examples/internal/proto/examplepb/response_body_service.proto
       - examples/internal/proto/examplepb/stream.proto
       - examples/internal/proto/examplepb/unannotated_echo_service.proto
@@ -100,6 +102,7 @@ lint:
       - examples/internal/proto/examplepb/excess_body.proto
       - examples/internal/proto/examplepb/non_standard_names.proto
       - examples/internal/proto/examplepb/opaque.proto
+      - examples/internal/proto/examplepb/proto3_field_semantics.proto
       - examples/internal/proto/examplepb/response_body_service.proto
       - examples/internal/proto/examplepb/stream.proto
       - examples/internal/proto/examplepb/unannotated_echo_service.proto
@@ -126,6 +129,7 @@ lint:
       - examples/internal/proto/examplepb/opaque.proto
       - examples/internal/proto/examplepb/openapi_merge_a.proto
       - examples/internal/proto/examplepb/openapi_merge_b.proto
+      - examples/internal/proto/examplepb/proto3_field_semantics.proto
       - examples/internal/proto/examplepb/response_body_service.proto
       - examples/internal/proto/examplepb/stream.proto
       - examples/internal/proto/examplepb/unannotated_echo_service.proto

examples/internal/proto/examplepb/BUILD.bazel

@@ -67,6 +67,7 @@ proto_library(
         "generated_output.proto",
         "ignore_comment.proto",
         "non_standard_names.proto",
+        "proto3_field_semantics.proto",
         "remove_internal_comment.proto",
         "response_body_service.proto",
         "stream.proto",

examples/internal/proto/examplepb/proto3_field_semantics.buf.gen.yaml

@@ -0,0 +1,6 @@
+version: v2
+plugins:
+  - local: protoc-gen-openapiv2
+    out: .
+    opt:
+      - use_proto3_field_semantics=true

examples/internal/proto/examplepb/proto3_field_semantics.proto

@@ -0,0 +1,40 @@
+syntax = "proto3";
+
+package grpc.gateway.examples.internal.proto.examplepb;
+
+import "google/api/annotations.proto";
+
+option go_package = "github.com/grpc-ecosystem/grpc-gateway/v2/examples/internal/proto/examplepb";
+
+service Proto3FieldSemanticsService {
+  rpc GetFilter(GetFilterRequest) returns (GetFilterResponse) {
+    option (google.api.http) = {get: "/v1/filter"};
+  }
+}
+
+message GetFilterRequest {
+  string name = 1;
+}
+
+message GetFilterResponse {
+  Filter filter = 1;
+}
+
+message Filter {
+  string name = 1;
+
+  oneof filter_union {
+    FilterCondition condition = 2;
+    FilterGroup group = 3;
+  }
+}
+
+message FilterCondition {
+  string field = 1;
+  string value = 2;
+}
+
+message FilterGroup {
+  repeated Filter filters = 1;
+  string operator = 2;
+}

examples/internal/proto/examplepb/proto3_field_semantics.swagger.json

@@ -0,0 +1,151 @@
+{
+  "swagger": "2.0",
+  "info": {
+    "title": "examples/internal/proto/examplepb/proto3_field_semantics.proto",
+    "version": "version not set"
+  },
+  "tags": [
+    {
+      "name": "Proto3FieldSemanticsService"
+    }
+  ],
+  "consumes": [
+    "application/json"
+  ],
+  "produces": [
+    "application/json"
+  ],
+  "paths": {
+    "/v1/filter": {
+      "get": {
+        "operationId": "Proto3FieldSemanticsService_GetFilter",
+        "responses": {
+          "200": {
+            "description": "A successful response.",
+            "schema": {
+              "$ref": "#/definitions/examplepbGetFilterResponse"
+            }
+          },
+          "default": {
+            "description": "An unexpected error response.",
+            "schema": {
+              "$ref": "#/definitions/rpcStatus"
+            }
+          }
+        },
+        "parameters": [
+          {
+            "name": "name",
+            "in": "query",
+            "required": true,
+            "type": "string"
+          }
+        ],
+        "tags": [
+          "Proto3FieldSemanticsService"
+        ]
+      }
+    }
+  },
+  "definitions": {
+    "examplepbFilter": {
+      "type": "object",
+      "properties": {
+        "name": {
+          "type": "string"
+        },
+        "condition": {
+          "$ref": "#/definitions/examplepbFilterCondition"
+        },
+        "group": {
+          "$ref": "#/definitions/examplepbFilterGroup"
+        }
+      },
+      "required": [
+        "name"
+      ]
+    },
+    "examplepbFilterCondition": {
+      "type": "object",
+      "properties": {
+        "field": {
+          "type": "string"
+        },
+        "value": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "field",
+        "value"
+      ]
+    },
+    "examplepbFilterGroup": {
+      "type": "object",
+      "properties": {
+        "filters": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "$ref": "#/definitions/examplepbFilter"
+          }
+        },
+        "operator": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "filters",
+        "operator"
+      ]
+    },
+    "examplepbGetFilterResponse": {
+      "type": "object",
+      "properties": {
+        "filter": {
+          "$ref": "#/definitions/examplepbFilter"
+        }
+      },
+      "required": [
+        "filter"
+      ]
+    },
+    "protobufAny": {
+      "type": "object",
+      "properties": {
+        "@type": {
+          "type": "string"
+        }
+      },
+      "additionalProperties": {},
+      "required": [
+        "typeUrl",
+        "value"
+      ]
+    },
+    "rpcStatus": {
+      "type": "object",
+      "properties": {
+        "code": {
+          "type": "integer",
+          "format": "int32"
+        },
+        "message": {
+          "type": "string"
+        },
+        "details": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "$ref": "#/definitions/protobufAny"
+          }
+        }
+      },
+      "required": [
+        "code",
+        "message",
+        "details"
+      ]
+    }
+  }
+}

protoc-gen-openapiv2/internal/genopenapi/template.go

@@ -3444,7 +3444,7 @@ func updateswaggerObjectFromJSONSchema(s *openapiSchemaObject, j *openapi_option
 func updateSwaggerObjectFromFieldBehavior(s *openapiSchemaObject, j []annotations.FieldBehavior, reg *descriptor.Registry, field *descriptor.Field) {
 	required := false
 	if reg.GetUseProto3FieldSemantics() {
-		required = !field.GetProto3Optional()
+		required = !field.GetProto3Optional() && field.OneofIndex == nil
 	}
 	for _, fb := range j {
 		switch fb {

protoc-gen-openapiv2/internal/genopenapi/template_test.go

@@ -11968,6 +11968,13 @@ func Test_updateSwaggerObjectFromFieldBehavior(t *testing.T) {
 		Number:         proto.Int32(1),
 		Proto3Optional: &boolTrue,
 	}}
+	oneofIndex := int32(0)
+	proto3FieldOneof := &descriptor.Field{FieldDescriptorProto: &descriptorpb.FieldDescriptorProto{
+		Name:       proto.String("name"),
+		Type:       descriptorpb.FieldDescriptorProto_TYPE_STRING.Enum(),
+		Number:     proto.Int32(1),
+		OneofIndex: &oneofIndex,
+	}}
 	tests := []struct {
 		name     string
 		args     args
@@ -12015,6 +12022,38 @@ func Test_updateSwaggerObjectFromFieldBehavior(t *testing.T) {
 			},
 			required: []string{"name"},
 		},
+		{
+			name: "Oneof field not required with proto3 field semantics",
+			args: args{
+				s:     &openapiSchemaObject{},
+				j:     []annotations.FieldBehavior{},
+				reg:   regWithProto3FieldSemantics,
+				field: proto3FieldOneof,
+			},
+			required: nil,
+		},
+		{
+			name: "Oneof field not required without proto3 field semantics",
+			args: args{
+				s:     &openapiSchemaObject{},
+				j:     []annotations.FieldBehavior{},
+				reg:   regWithNoProto3FieldSemantics,
+				field: proto3FieldOneof,
+			},
+			required: nil,
+		},
+		{
+			name: "Oneof field required when explicitly annotated REQUIRED",
+			args: args{
+				s: &openapiSchemaObject{},
+				j: []annotations.FieldBehavior{
+					annotations.FieldBehavior_REQUIRED,
+				},
+				reg:   regWithProto3FieldSemantics,
+				field: proto3FieldOneof,
+			},
+			required: []string{"name"},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {