Xcode11's platformFilter is ignored in PBXTargetDependency.swift

[jbuchman]

Context 🕵️‍♀️

When writing iOS apps with watchOS target dependencies and also supporting macOS Catalyst, the target's platformFilter in the target dependencies is being ignored when reading and writing project.pbxproj file.

What 🌱

My app which has watchOS, iOS and macOS/Catalyst components has a target in which the iOS app is compiled. That target includes a dependency on the watchOS target as well. To resolve the fact that you can't embed a watchOS target in a Catalyst app, I select "iOS" from the Platforms dropdown in the Dependencies of the Build Phases tab. However, when reading/writing the project files using this xcodeproj library, this dropdown setting is forgotten.

Proposal 🎉

From 924fcef87cf4202786240f47b3fc6db20e82e840 Mon Sep 17 00:00:00 2001
From: Jeremy Buchman <[email protected]>
Date: Tue, 25 Feb 2020 16:03:51 -0700
Subject: [PATCH] Added platformFilter to target dependency for Xcode 11
 support (WatchOS + Catalyst)

---
 .../Objects/Targets/PBXTargetDependency.swift         | 11 +++++++++++
 .../Objects/Project/PBXProjIntegrationTests.swift     |  3 +++
 2 files changed, 14 insertions(+)

diff --git a/Sources/XcodeProj/Objects/Targets/PBXTargetDependency.swift b/Sources/XcodeProj/Objects/Targets/PBXTargetDependency.swift
index a21e721..817813e 100644
--- a/Sources/XcodeProj/Objects/Targets/PBXTargetDependency.swift
+++ b/Sources/XcodeProj/Objects/Targets/PBXTargetDependency.swift
@@ -7,6 +7,10 @@ public final class PBXTargetDependency: PBXObject {
     /// Target name.
     public var name: String?
 
+    /// Platform filter attribute.
+    /// Introduced in: Xcode 11
+    public var platformFilter: String?
+    
     /// Target reference.
     var targetReference: PBXObjectReference?
 
@@ -72,6 +76,7 @@ public final class PBXTargetDependency: PBXObject {
         case target
         case targetProxy
         case productRef
+        case platformFilter
     }
 
     public required init(from decoder: Decoder) throws {
@@ -79,6 +84,7 @@ public final class PBXTargetDependency: PBXObject {
         let referenceRepository = decoder.context.objectReferenceRepository
         let objects = decoder.context.objects
         name = try container.decodeIfPresent(.name)
+        platformFilter = try container.decodeIfPresent(.platformFilter)
         if let targetReference: String = try container.decodeIfPresent(.target) {
             self.targetReference = referenceRepository.getOrCreate(reference: targetReference, objects: objects)
         }
@@ -101,6 +107,11 @@ extension PBXTargetDependency: PlistSerializable {
         if let name = name {
             dictionary["name"] = .string(CommentedString(name))
         }
+        
+        if let platformFilter = platformFilter {
+            dictionary["platformFilter"] = .string(.init(platformFilter))
+        }
+        
         if let targetReference = targetReference {
             let targetObject: PBXTarget? = targetReference.getObject()
             dictionary["target"] = .string(CommentedString(targetReference.value, comment: targetObject?.name))

PS: I would have just submitted a pull request, but I couldn't resolve an issue with one of the tests and thus I couldn't get the project to compile without commenting out that test. (PBXProjIntegrationTests.swift)