fix(GraphQL): Fix squashIntoObject so that results are correctly merg…

…ed (#6416)

While creating the add mutation, we weren't squashing different bits correctly which led to the incorrect mutation being sent to Dgraph. This change modifies the set to append for []interface{} to fix that.

Fixes GRAPHQL-679

graphql/e2e/common/common.go

@@ -329,6 +329,7 @@ func RunAll(t *testing.T) {
 	t.Run("add multiple mutations", testMultipleMutations)
 	t.Run("deep XID mutations", deepXIDMutations)
 	t.Run("three level xid", testThreeLevelXID)
+	t.Run("nested add mutation with @hasInverse", nestedAddMutationWithHasInverse)
 	t.Run("error in multiple mutations", addMultipleMutationWithOneError)
 	t.Run("dgraph directive with reverse edge adds data correctly",
 		addMutationWithReverseDgraphEdge)

graphql/e2e/common/mutation.go

@@ -3652,32 +3652,97 @@ func int64BoundaryTesting(t *testing.T) {
 	//This test checks the range of Int64
 	//(2^63)=9223372036854775808
 	addPost1Params := &GraphQLParams{
-		Query: `mutation {	
-			addpost1(input: [{title: "Dgraph", numLikes: 9223372036854775807 },{title: "Dgraph1", numLikes: -9223372036854775808 }]) {	
-				post1 {	
-					title	
-					numLikes	
-				}	
-			}	
+		Query: `mutation {
+			addpost1(input: [{title: "Dgraph", numLikes: 9223372036854775807 },{title: "Dgraph1", numLikes: -9223372036854775808 }]) {
+				post1 {
+					title
+					numLikes
+				}
+			}
 		}`,
 	}
 
 	gqlResponse := addPost1Params.ExecuteAsPost(t, GraphqlURL)
 	RequireNoGQLErrors(t, gqlResponse)
 
-	addPost1Expected := `{	
-		"addpost1": {	
-			"post1": [{	
-				"title": "Dgraph",	
-				"numLikes": 9223372036854775807	
-					
-			},{	
-				"title": "Dgraph1",	
-				"numLikes": -9223372036854775808	
-			}]	
-		}	
+	addPost1Expected := `{
+		"addpost1": {
+			"post1": [{
+				"title": "Dgraph",
+				"numLikes": 9223372036854775807
+
+			},{
+				"title": "Dgraph1",
+				"numLikes": -9223372036854775808
+			}]
+		}
 	}`
 	testutil.CompareJSON(t, addPost1Expected, string(gqlResponse.Data))
 	filter := map[string]interface{}{"title": map[string]interface{}{"regexp": "/Dgraph.*/"}}
 	deleteGqlType(t, "post1", filter, 2, nil)
 }
+
+func nestedAddMutationWithHasInverse(t *testing.T) {
+	params := &GraphQLParams{
+		Query: `mutation addPerson1($input: [AddPerson1Input!]!) {
+			addPerson1(input: $input) {
+				person1 {
+					name
+					friends {
+						name
+						friends {
+							name
+						}
+					}
+				}
+			}
+		}`,
+		Variables: map[string]interface{}{
+			"input": []interface{}{
+				map[string]interface{}{
+					"name": "Or",
+					"friends": []interface{}{
+						map[string]interface{}{
+							"name": "Michal",
+							"friends": []interface{}{
+								map[string]interface{}{
+									"name": "Justin",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	gqlResponse := postExecutor(t, GraphqlURL, params)
+	RequireNoGQLErrors(t, gqlResponse)
+
+	expected := `{
+		"addPerson1": {
+		  "person1": [
+			{
+			  "friends": [
+				{
+				  "friends": [
+					{
+					  "name": "Or"
+					},
+					{
+					  "name": "Justin"
+					}
+				  ],
+				  "name": "Michal"
+				}
+			  ],
+			  "name": "Or"
+			}
+		  ]
+		}
+	  }`
+	testutil.CompareJSON(t, expected, string(gqlResponse.Data))
+
+	// cleanup
+	deleteGqlType(t, "Person1", map[string]interface{}{}, 3, nil)
+}

graphql/e2e/directives/schema.graphql

@@ -177,4 +177,10 @@ type post1{
     id: ID
     title: String! @id @search(by: [regexp])
     numLikes: Int64
-}
+}
+
+type Person1 {
+    id: ID!
+    name: String!
+    friends: [Person1] @hasInverse(field: friends)
+}

graphql/e2e/directives/schema_response.json

@@ -68,6 +68,15 @@
             ],
             "upsert": true
         },
+        {
+            "predicate": "Person1.name",
+            "type": "string"
+        },
+        {
+            "predicate": "Person1.friends",
+            "type": "uid",
+            "list": true
+        },
         {
             "predicate": "Post1.comments",
             "type": "uid",
@@ -457,6 +466,17 @@
             ],
             "name": "People"
         },
+        {
+            "fields": [
+                {
+                    "name": "Person1.name"
+                },
+                {
+                    "name": "Person1.friends"
+                }
+            ],
+            "name": "Person1"
+        },
         {
             "fields": [
                 {

graphql/e2e/normal/schema.graphql

@@ -178,4 +178,10 @@ type post1{
         id: ID
         title: String! @id @search(by: [regexp])
         numLikes: Int64
-}
+}
+
+type Person1 {
+    id: ID!
+    name: String!
+    friends: [Person1] @hasInverse(field: friends)
+}

graphql/e2e/normal/schema_response.json

@@ -150,6 +150,15 @@
             "predicate": "Person.name",
             "type": "string"
         },
+        {
+            "predicate": "Person1.name",
+            "type": "string"
+        },
+        {
+            "predicate": "Person1.friends",
+            "type": "uid",
+            "list": true
+        },
         {
             "predicate": "Post.author",
             "type": "uid"
@@ -510,6 +519,17 @@
             ],
             "name": "Person"
         },
+        {
+            "fields": [
+                {
+                    "name": "Person1.name"
+                },
+                {
+                    "name": "Person1.friends"
+                }
+            ],
+            "name": "Person1"
+        },
         {
             "fields": [
                 {

graphql/resolve/add_mutation_test.yaml

@@ -2413,3 +2413,61 @@
   explanation: "The add mutation should not be allowed since value of @id field is empty."
   error:
     { "message": "failed to rewrite mutation payload because encountered an empty value for @id field `State.code`" }
+
+-
+  name: "Add mutation for person with @hasInverse"
+  gqlmutation: |
+    mutation($input: [AddPersonInput!]!) {
+      addPerson(input: $input) {
+        person {
+          name
+        }
+      }
+    }
+  gqlvariables: |
+    {
+      "input": [
+        {
+          "name": "Or",
+          "friends": [
+            { "name": "Michal", "friends": [{ "name": "Justin" }] }
+          ]
+        }
+      ]
+    }
+  dgmutations:
+    - setjson: |
+        {
+          "Person.friends": [
+            {
+              "Person.friends": [
+                {
+                  "uid": "_:Person1"
+                },
+                {
+                  "Person.friends": [
+                    {
+                      "uid": "_:Person2"
+                    }
+                  ],
+                  "Person.name": "Justin",
+                  "dgraph.type": [
+                    "Person"
+                  ],
+                  "uid": "_:Person3"
+                }
+              ],
+              "Person.name": "Michal",
+              "dgraph.type": [
+                "Person"
+              ],
+              "uid": "_:Person2"
+            }
+          ],
+          "Person.name": "Or",
+          "dgraph.type": [
+            "Person"
+          ],
+          "uid": "_:Person1"
+        }
+

graphql/resolve/mutation_rewriter.go

@@ -1727,7 +1727,27 @@ func squashIntoObject(label string) func(interface{}, interface{}, bool) interfa
 			}
 			asObject = cpy
 		}
-		asObject[label] = v
+
+		val := v
+
+		// If there is an existing value for the label in the object, then we should append to it
+		// instead of overwriting it if the existing value is a list. This can happen when there
+		// is @hasInverse and we are doing nested adds.
+		existing := asObject[label]
+		switch ev := existing.(type) {
+		case []interface{}:
+			switch vv := v.(type) {
+			case []interface{}:
+				ev = append(ev, vv...)
+				val = ev
+			case interface{}:
+				ev = append(ev, vv)
+				val = ev
+			default:
+			}
+		default:
+		}
+		asObject[label] = val
 		return asObject
 	}
 }

graphql/resolve/schema.graphql

@@ -283,6 +283,12 @@ type ThingTwo implements Thing {
     owner: String
 }
 
+type Person {
+    id: ID!
+    name: String @search(by: [hash])
+    friends: [Person] @hasInverse(field: friends)
+}
+
 interface A {
     name: String! @id
 }