fix(i): Default field value overwrite on update (#3030)

## Relevant issue(s)

Resolves #3029

## Description

This PR fixes an issue where default field values would overwrite any
missing input fields.

## Tasks

- [x] I made sure the code is well commented, particularly
hard-to-understand areas.
- [x] I made sure the repository-held documentation is changed
accordingly.
- [x] I made sure the pull request title adheres to the conventional
commit style (the subset used in the project can be found in
[tools/configs/chglog/config.yml](tools/configs/chglog/config.yml)).
- [x] I made sure to discuss its limitations such as threats to
validity, vulnerability to mistake and misuse, robustness to
invalidation of assumptions, resource requirements, ...

## How has this been tested?

Added integration test

Specify the platform(s) on which this was tested:
- MacOS

internal/request/graphql/schema/generate.go

@@ -583,8 +583,7 @@ func (g *Generator) buildMutationInputTypes(collections []client.CollectionDefin
 				}
 
 				fields[field.Name] = &gql.InputObjectFieldConfig{
-					Type:         ttype,
-					DefaultValue: field.DefaultValue,
+					Type: ttype,
 				}
 			}
 

tests/integration/mutation/update/with_default_values_test.go

@@ -0,0 +1,62 @@
+// Copyright 2024 Democratized Data Foundation
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package update
+
+import (
+	"testing"
+
+	testUtils "github.com/sourcenetwork/defradb/tests/integration"
+)
+
+func TestMutationUpdate_WithDefaultValues_DoesNotOverwrite(t *testing.T) {
+	test := testUtils.TestCase{
+		Description: "Simple update mutation with default value does not overwrite",
+		Actions: []any{
+			testUtils.SchemaUpdate{
+				Schema: `
+					type Users {
+						name: String 
+						score: Int @default(int: 100)
+					}
+				`,
+			},
+			testUtils.CreateDoc{
+				Doc: `{
+					"name": "John",
+					"score": 0
+				}`,
+			},
+			testUtils.UpdateDoc{
+				Doc: `{
+					"name": "Fred"
+				}`,
+			},
+			testUtils.Request{
+				Request: `query {
+					Users {
+						name
+						score
+					}
+				}`,
+				Results: map[string]any{
+					"Users": []map[string]any{
+						{
+							"name":  "Fred",
+							"score": int64(0),
+						},
+					},
+				},
+			},
+		},
+	}
+
+	testUtils.ExecuteTestCase(t, test)
+}