keep the metadata and links for the merged-in document body if the merged-into document body has no metadata or links.

Author: mattpolzin

Sources/JSONAPI/Document/Document.swift

@@ -272,11 +272,11 @@ extension Document.Body.Data where PrimaryResourceBody: ResourceBodyAppendable {
 }
 
 extension Document.Body.Data where PrimaryResourceBody: ResourceBodyAppendable, MetaType == NoMetadata, LinksType == NoLinks {
-    public func merging<OtherMeta, OtherLinks, OtherDescription, OtherError>(_ other: Document<PrimaryResourceBody, OtherMeta, OtherLinks, IncludeType, OtherDescription, OtherError>.Body.Data) -> Document.Body.Data {
-        return Document.Body.Data(primary: primary.appending(other.primary),
-                                  includes: includes.appending(other.includes),
-                                  meta: meta,
-                                  links: links)
+    public func merging<OtherMeta, OtherLinks, OtherDescription, OtherError>(_ other: Document<PrimaryResourceBody, OtherMeta, OtherLinks, IncludeType, OtherDescription, OtherError>.Body.Data) -> Document<PrimaryResourceBody, OtherMeta, OtherLinks, IncludeType, APIDescription, Error>.Body.Data {
+        return .init(primary: primary.appending(other.primary),
+                     includes: includes.appending(other.includes),
+                     meta: other.meta,
+                     links: other.links)
     }
 }
 

Tests/JSONAPITests/Document/DocumentTests.swift

@@ -1543,6 +1543,8 @@ extension DocumentTests {
     let combined = bodyData1.merging(bodyData2)
 
     XCTAssertEqual(combined.primary.values, bodyData1.primary.values + bodyData2.primary.values)
+    XCTAssertEqual(combined.meta, bodyData2.meta)
+    XCTAssertEqual(combined.links, bodyData2.links)
   }
 
 	public func test_MergeBodyDataWithMergeFunctions() {