From 3dc7d249caa1d1e099421fc07b4cd07ee1709278 Mon Sep 17 00:00:00 2001
From: Ian Leitch <ian@leitch.io>
Date: Sun, 31 Dec 2023 16:28:37 +0000
Subject: [PATCH] Don't retain RawRepresentable CodingKey enum cases

---
 .../Mutators/EnumCaseReferenceBuilder.swift            |  6 +++++-
 .../Fixtures/RetentionFixtures/testCodingKeyEnum.swift | 10 ++++++++++
 Tests/PeripheryTests/RetentionTest.swift               |  9 +++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/Sources/PeripheryKit/SourceGraph/Mutators/EnumCaseReferenceBuilder.swift b/Sources/PeripheryKit/SourceGraph/Mutators/EnumCaseReferenceBuilder.swift
index 7f94e516f..706a23841 100644
--- a/Sources/PeripheryKit/SourceGraph/Mutators/EnumCaseReferenceBuilder.swift
+++ b/Sources/PeripheryKit/SourceGraph/Mutators/EnumCaseReferenceBuilder.swift
@@ -11,7 +11,11 @@ final class EnumCaseReferenceBuilder: SourceGraphMutator {
 
     func mutate() {
         for enumDeclaration in graph.declarations(ofKind: .enum) {
-            if isRawRepresentable(enumDeclaration) {
+            let isCodingKey = graph.inheritedTypeReferences(of: enumDeclaration).contains {
+                $0.kind == .protocol && $0.name == "CodingKey"
+            }
+
+            if !isCodingKey, isRawRepresentable(enumDeclaration) {
                 let enumCases = enumDeclaration.declarations.filter { $0.kind == .enumelement }
 
                 for enumCase in enumCases {
diff --git a/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift b/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift
index e4c5fafeb..ab370d92a 100644
--- a/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift
+++ b/Tests/Fixtures/RetentionFixtures/testCodingKeyEnum.swift
@@ -72,3 +72,13 @@ public class FixtureClass220: Encodable {
         case someUnusedVar
     }
 }
+
+public struct FixtureStruct220: Encodable {
+    public var someUsedVar: String?
+    var someUnusedVar: String?
+
+    enum CodingKeys: String, CodingKey {
+        case someUsedVar
+        case someUnusedVar
+    }
+}
diff --git a/Tests/PeripheryTests/RetentionTest.swift b/Tests/PeripheryTests/RetentionTest.swift
index 389385f6d..d5792aaaf 100644
--- a/Tests/PeripheryTests/RetentionTest.swift
+++ b/Tests/PeripheryTests/RetentionTest.swift
@@ -578,6 +578,15 @@ final class RetentionTest: FixtureSourceGraphTestCase {
                 self.assertReferenced(.varInstance("someUsedVar"))
                 self.assertNotReferenced(.varInstance("someUnusedVar"))
 
+                self.assertReferenced(.enum("CodingKeys")) {
+                    self.assertReferenced(.enumelement("someUsedVar"))
+                    self.assertNotReferenced(.enumelement("someUnusedVar"))
+                }
+            }
+            assertReferenced(.struct("FixtureStruct220")) {
+                self.assertReferenced(.varInstance("someUsedVar"))
+                self.assertNotReferenced(.varInstance("someUnusedVar"))
+
                 self.assertReferenced(.enum("CodingKeys")) {
                     self.assertReferenced(.enumelement("someUsedVar"))
                     self.assertNotReferenced(.enumelement("someUnusedVar"))