Show difference when values are equal if labels differ (#84)

Author: stephencelis

Sources/CustomDump/Diff.swift

@@ -38,7 +38,7 @@ public func diff<T>(_ lhs: T, _ rhs: T, format: DiffFormat = .default) -> String
     isRoot: Bool
   ) -> String {
     let rhsName = rhsName ?? lhsName
-    guard !isMirrorEqual(lhs, rhs) else {
+    guard lhsName != rhsName || !isMirrorEqual(lhs, rhs) else {
       return _customDump(lhs, name: rhsName, indent: indent, isRoot: isRoot, maxDepth: 0)
         .appending(separator)
         .indenting(with: format.both + " ")

Tests/CustomDumpTests/DiffTests.swift

@@ -1064,4 +1064,47 @@ final class DiffTests: XCTestCase {
       """
     )
   }
+
+  func testCustomDictionary() {
+    struct Stack: CustomDumpReflectable {
+      var elements: [(ID, String)]
+
+      struct ID: CustomDumpStringConvertible, Hashable {
+        let rawValue: Int
+        var customDumpDescription: String {
+          "#\(self.rawValue)"
+        }
+      }
+
+      var customDumpMirror: Mirror {
+        Mirror(
+          self,
+          unlabeledChildren: self.elements,
+          displayStyle: .dictionary
+        )
+      }
+    }
+
+    XCTAssertEqual(
+      String(customDumping: Stack(elements: [(.init(rawValue: 0), "Hello")])),
+      """
+      [
+        #0: "Hello"
+      ]
+      """
+    )
+
+    XCTAssertEqual(
+      diff(
+        Stack(elements: [(.init(rawValue: 0), "Hello")]),
+        Stack(elements: [(.init(rawValue: 1), "Hello")])
+      ),
+      """
+        [
+      -   #0: "Hello"
+      +   #1: "Hello"
+        ]
+      """
+    )
+  }
 }