From 654c0fd61270722157eba8846c991be2c856735a Mon Sep 17 00:00:00 2001
From: Dan Federman <dfed@me.com>
Date: Mon, 11 Dec 2023 07:54:42 -0800
Subject: [PATCH] Do not parse third-party code in Swift Package plugin

---
 .../SafeDIGenerateDependencyTree.swift        | 24 ++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/Plugins/SafeDIGenerateDependencyTree/SafeDIGenerateDependencyTree.swift b/Plugins/SafeDIGenerateDependencyTree/SafeDIGenerateDependencyTree.swift
index 40d5ca2b..2a05e429 100644
--- a/Plugins/SafeDIGenerateDependencyTree/SafeDIGenerateDependencyTree.swift
+++ b/Plugins/SafeDIGenerateDependencyTree/SafeDIGenerateDependencyTree.swift
@@ -44,12 +44,30 @@ struct SafeDIGenerateDependencyTree: BuildToolPlugin {
 
 extension Target {
 
-    var sourceModuleRecursiveDependencies: [SourceModuleTarget] {
+    var sourceModuleRecursiveDependencies: [SwiftSourceModuleTarget] {
         recursiveTargetDependencies.compactMap {
-            $0 as? SourceModuleTarget
+            // Since we only understand Swift files, we only care about SwiftSourceModuleTargets.
+            guard let swiftModule = $0 as? SwiftSourceModuleTarget else {
+                return nil
+            }
+
+            // We only care about first-party code. Ignore third-party dependencies.
+            guard
+                swiftModule
+                    .directory
+                    // Removing the module name.
+                    .removingLastComponent()
+                    // Removing 'Sources'.
+                    .removingLastComponent()
+                    // Removing the package name.
+                    .removingLastComponent()
+                    .lastComponent != "checkouts"
+            else {
+                return nil
+            }
+            return swiftModule
         }
     }
-
 }
 
 #if canImport(XcodeProjectPlugin)