From c5dd33f72d04829b405ffdf01a96eb28012d4a1c Mon Sep 17 00:00:00 2001
From: Reuven Harrison <reuvenharrison@gmail.com>
Date: Mon, 8 Apr 2024 23:44:53 +0300
Subject: [PATCH] add Empty check to jsonPatch (#520)

Co-authored-by: Reuven <rh@tufin.com>
---
 data/extensions/openapi-2.json | 95 ++++++++++++++++++++++++++++++++++
 diff/diff_test.go              | 11 ++++
 diff/interface_map_diff.go     |  4 +-
 diff/json_diff.go              |  5 ++
 4 files changed, 114 insertions(+), 1 deletion(-)
 create mode 100644 data/extensions/openapi-2.json

diff --git a/data/extensions/openapi-2.json b/data/extensions/openapi-2.json
new file mode 100644
index 00000000..df0256f3
--- /dev/null
+++ b/data/extensions/openapi-2.json
@@ -0,0 +1,95 @@
+{
+  "openapi": "3.0.0",
+  "paths": {
+    "/v1alpha1/generic": {
+      "put": {
+        "operationId": "GenericController_request",
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "properties": {
+                  "resources": {
+                    "type": "array",
+                    "minItems": 1,
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "id": {
+                          "type": "string"
+                        },
+                        "kind": {
+                          "oneOf": [
+                            {
+                              "type": "string",
+                              "enum": [
+                                "foo",
+                                "bar",
+                                "fizz",
+                                "buzz"
+                              ],
+                              "x-enumNames": [
+                                "FOO",
+                                "BAR",
+                                "FIZZ",
+                                "BUZZ"
+                              ]
+                            },
+                            {
+                              "type": "string",
+                              "enum": [
+                                "self"
+                              ],
+                              "x-enumNames": [
+                                "SELF"
+                              ]
+                            }
+                          ]
+                        }
+                      },
+                      "required": [
+                        "id",
+                        "kind"
+                      ]
+                    }
+                  }
+                },
+                "required": [
+                  "resources"
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "properties": {
+                    "id": {
+                      "type": "number"
+                    }
+                  },
+                  "required": [
+                    "id"
+                  ]
+                }
+              }
+            }
+          }
+        },
+        "tags": []
+      }
+    }
+  },
+  "tags": [],
+  "servers": [],
+  "components": {
+    "schemas": {}
+  }
+}
\ No newline at end of file
diff --git a/diff/diff_test.go b/diff/diff_test.go
index 1b89f68b..9c19aff5 100644
--- a/diff/diff_test.go
+++ b/diff/diff_test.go
@@ -915,3 +915,14 @@ func TestDiff_ExtensionsInvalidImplicit(t *testing.T) {
 	_, _, err = diff.GetWithOperationsSourcesMap(diff.NewConfig(), s1, s1)
 	require.EqualError(t, err, "json: unsupported type: chan int")
 }
+
+func TestDiff_ExtensionsIssue519(t *testing.T) {
+	loader := openapi3.NewLoader()
+
+	s1, err := load.NewSpecInfo(loader, load.NewSource("../data/extensions/openapi-2.json"))
+	require.NoError(t, err)
+
+	d, _, err := diff.GetWithOperationsSourcesMap(diff.NewConfig(), s1, s1)
+	require.NoError(t, err)
+	require.Empty(t, d)
+}
diff --git a/diff/interface_map_diff.go b/diff/interface_map_diff.go
index 6ce23bcc..ea966997 100644
--- a/diff/interface_map_diff.go
+++ b/diff/interface_map_diff.go
@@ -56,7 +56,9 @@ func getInterfaceMapDiffInternal(map1, map2 InterfaceMap) (*InterfaceMapDiff, er
 			if err != nil {
 				return nil, err
 			}
-			result.Modified[name1] = patch
+			if !patch.Empty() {
+				result.Modified[name1] = patch
+			}
 		} else {
 			result.Deleted = append(result.Deleted, name1)
 		}
diff --git a/diff/json_diff.go b/diff/json_diff.go
index 63d1f7d7..0cc9e9a7 100644
--- a/diff/json_diff.go
+++ b/diff/json_diff.go
@@ -7,6 +7,11 @@ import (
 // jsonPatch is a wrapper to jsondiff.jsonPatch with proper serialization for json and yaml
 type jsonPatch []*jsonOperation
 
+// Empty indicates whether a change was found in this element
+func (p jsonPatch) Empty() bool {
+	return len(p) == 0
+}
+
 // jsonOperation is a wrapper to jsondiff.jsonOperation with proper serialization for json and yaml
 type jsonOperation struct {
 	OldValue interface{} `json:"oldValue" yaml:"oldValue"`