Add ids to second occurrence of a type within a dump (#60)

* Add ids to second occurrence of a type within a dump

* Update logic

* Cleanup

* Update tests after rebase

* Use # instead of <>

Author: tahirmt

Sources/CustomDump/Dump.swift

@@ -57,6 +57,8 @@ public func customDump<T, TargetStream>(
   maxDepth: Int = .max
 ) -> T where TargetStream: TextOutputStream {
 
+  var idPerItem: [ObjectIdentifier: UInt] = [:]
+  var occurencePerType: [String: UInt] = [:]
   var visitedItems: Set<ObjectIdentifier> = []
 
   func customDumpHelp<T, TargetStream>(
@@ -134,10 +136,21 @@ public func customDump<T, TargetStream>(
 
     case let (value as AnyObject, .class?):
       let item = ObjectIdentifier(value)
+      var occurence = occurencePerType[typeName(mirror.subjectType), default: 0] {
+        didSet { occurencePerType[typeName(mirror.subjectType)] = occurence }
+      }
+
+      var id: String {
+        let id = idPerItem[item, default: occurence]
+        idPerItem[item] = id
+
+        return id > 1 ? "#\(id)" : ""
+      }
       if visitedItems.contains(item) {
-        out.write("\(typeName(mirror.subjectType))(↩︎)")
+        out.write("\(typeName(mirror.subjectType))\(id)(↩︎)")
       } else {
         visitedItems.insert(item)
+        occurence += 1
         var children = Array(mirror.children)
 
         var superclassMirror = mirror.superclassMirror
@@ -147,7 +160,7 @@ public func customDump<T, TargetStream>(
         }
         dumpChildren(
           of: Mirror(value, children: children),
-          prefix: "\(typeName(mirror.subjectType))(",
+          prefix: "\(typeName(mirror.subjectType))\(id)(",
           suffix: ")"
         )
       }

Tests/CustomDumpTests/DumpTests.swift

@@ -824,23 +824,23 @@ final class DumpTests: XCTestCase {
             name: "Virginia",
             parent: DumpTests.Parent(↩︎)
           ),
-          [1]: DumpTests.Child(
+          [1]: DumpTests.Child#2(
             name: "Ronald",
             parent: DumpTests.Parent(↩︎)
           ),
-          [2]: DumpTests.Child(
+          [2]: DumpTests.Child#3(
             name: "Fred",
             parent: DumpTests.Parent(↩︎)
           ),
-          [3]: DumpTests.Child(
+          [3]: DumpTests.Child#4(
             name: "George",
             parent: DumpTests.Parent(↩︎)
           ),
-          [4]: DumpTests.Child(
+          [4]: DumpTests.Child#5(
             name: "Percy",
             parent: DumpTests.Parent(↩︎)
           ),
-          [5]: DumpTests.Child(
+          [5]: DumpTests.Child#6(
             name: "Charles",
             parent: DumpTests.Parent(↩︎)
           )
@@ -853,40 +853,70 @@ final class DumpTests: XCTestCase {
   func testRepeatition() {
     class Human {
       let name = "John"
+    }
+
+    class User: Human {
       let email = "[email protected]"
       let age = 97
+
+      let human: Human
+
+      init(human: Human) {
+        self.human = human
+      }
     }
 
     let human = Human()
     let human2 = Human()
 
+    let user = User(human: human)
+    let user2 = User(human: human2)
+
     var dump = ""
     customDump(
-      [
-        human,
-        human,
-        human2,
-        human2,
-      ], to: &dump)
-
-    XCTAssertNoDifference(
-      dump,
-      """
-      [
-        [0]: DumpTests.Human(
-          name: "John",
-          email: "[email protected]",
-          age: 97
-        ),
-        [1]: DumpTests.Human(↩︎),
-        [2]: DumpTests.Human(
-          name: "John",
-          email: "[email protected]",
-          age: 97
-        ),
-        [3]: DumpTests.Human(↩︎)
-      ]
-      """
+    [
+      human,
+      human,
+      human,
+      human2,
+      human2,
+      human2,
+      user,
+      user,
+      user,
+      user2,
+      user2,
+      user2,
+    ], to: &dump)
+
+    XCTAssertNoDifference(
+      dump,
+       """
+       [
+         [0]: DumpTests.Human(name: "John"),
+         [1]: DumpTests.Human(↩︎),
+         [2]: DumpTests.Human(↩︎),
+         [3]: DumpTests.Human#2(name: "John"),
+         [4]: DumpTests.Human#2(↩︎),
+         [5]: DumpTests.Human#2(↩︎),
+         [6]: DumpTests.User(
+           name: "John",
+           email: "[email protected]",
+           age: 97,
+           human: DumpTests.Human(↩︎)
+         ),
+         [7]: DumpTests.User(↩︎),
+         [8]: DumpTests.User(↩︎),
+         [9]: DumpTests.User#2(
+           name: "John",
+           email: "[email protected]",
+           age: 97,
+           human: DumpTests.Human#2(↩︎)
+         ),
+         [10]: DumpTests.User#2(↩︎),
+         [11]: DumpTests.User#2(↩︎)
+       ]
+       """
     )
   }