v2Tov3: handle parameter schema refs (#455)

Co-authored-by: Vincent Behar <[email protected]>

Author: fenollp

openapi2conv/openapi2_conv.go

@@ -298,6 +298,10 @@ func ToV3Parameter(components *openapi3.Components, parameter *openapi2.Paramete
 			required = true
 		}
 
+		var schemaRefRef string
+		if schemaRef := parameter.Schema; schemaRef != nil && schemaRef.Ref != "" {
+			schemaRefRef = schemaRef.Ref
+		}
 		result := &openapi3.Parameter{
 			In:             parameter.In,
 			Name:           parameter.Name,
@@ -322,7 +326,9 @@ func ToV3Parameter(components *openapi3.Components, parameter *openapi2.Paramete
 				AllowEmptyValue: parameter.AllowEmptyValue,
 				UniqueItems:     parameter.UniqueItems,
 				MultipleOf:      parameter.MultipleOf,
-			}}),
+			},
+				Ref: schemaRefRef,
+			}),
 		}
 		return &openapi3.ParameterRef{Value: result}, nil, nil, nil
 	}
@@ -980,6 +986,10 @@ func FromV3Parameter(ref *openapi3.ParameterRef, components *openapi3.Components
 	}
 	if schemaRef := parameter.Schema; schemaRef != nil {
 		schemaRef, _ = FromV3SchemaRef(schemaRef, components)
+		if ref := schemaRef.Ref; ref != "" {
+			result.Schema = &openapi3.SchemaRef{Ref: FromV3Ref(ref)}
+			return result, nil
+		}
 		schema := schemaRef.Value
 		result.Type = schema.Type
 		result.Format = schema.Format

openapi2conv/openapi2_conv_test.go

@@ -79,6 +79,14 @@ const exampleV2 = `
 		"ItemExtension": {
 			"description": "It could be anything.",
 			"type": "boolean"
+		},
+		"foo": {
+			"description": "foo description",
+			"enum": [
+				"bar",
+				"baz"
+			],
+			"type": "string"
 		}
 	},
 	"externalDocs": {
@@ -305,6 +313,34 @@ const exampleV2 = `
 			},
 			"x-path": "path extension 1",
 			"x-path2": "path extension 2"
+		},
+		"/foo": {
+			"get": {
+				"operationId": "getFoo",
+				"consumes": [
+					"application/json",
+					"application/xml"
+				],
+				"parameters": [
+					{
+						"x-originalParamName": "foo",
+						"in": "body",
+						"name": "foo",
+						"schema": {
+							"$ref": "#/definitions/foo"
+						}
+					}
+				],
+				"responses": {
+					"default": {
+						"description": "OK",
+						"schema": {
+							"$ref": "#/definitions/foo"
+						}
+					}
+				},
+				"summary": "get foo"
+			}
 		}
 	},
 	"responses": {
@@ -420,6 +456,14 @@ const exampleV3 = `
 				"type": "string",
 				"x-formData-name": "fileUpload2",
 				"x-mimetype": "text/plain"
+			},
+			"foo": {
+				"description": "foo description",
+				"enum": [
+					"bar",
+					"baz"
+				],
+				"type": "string"
 			}
 		}
 	},
@@ -646,6 +690,39 @@ const exampleV3 = `
 			},
 			"x-path": "path extension 1",
 			"x-path2": "path extension 2"
+		},
+		"/foo": {
+			"get": {
+				"operationId": "getFoo",
+				"requestBody": {
+					"x-originalParamName": "foo",
+					"content": {
+						"application/json": {
+							"schema": {
+								"$ref": "#/components/schemas/foo"
+							}
+						},
+						"application/xml": {
+							"schema": {
+								"$ref": "#/components/schemas/foo"
+							}
+						}
+					}
+				},
+				"responses": {
+					"default": {
+						"content": {
+							"application/json": {
+								"schema": {
+									"$ref": "#/components/schemas/foo"
+								}
+							}
+						},
+						"description": "OK"
+					}
+				},
+				"summary": "get foo"
+			}
 		}
 	},
 	"security": [