Slightly improved heuristic to find the target root

Use the longest path where one of the components is the target name

Plugins/Enlighter/Enlighter.swift

@@ -176,8 +176,8 @@ struct Enlighter: BuildToolPlugin {
       configuration: configuration
     )
     guard !groups.isEmpty else {
-      print("Target contains not matching files:", target.name)
-      debugLog("Target contains not matching files:", target.name)
+      print("Could not find matching files in", target.directory)
+      debugLog("Could not find matching files in", target.directory)
       return []
     }
 
@@ -340,8 +340,8 @@ extension Enlighter: XcodeBuildToolPlugin {
       configuration: configuration
     )
     guard !groups.isEmpty else {
-      print("Target contains not matching files:", target.name)
-      debugLog("Target contains not matching files:", target.name)
+      print("Could not find matching files in", target.directory)
+      debugLog("Could not find matching files in", target.directory)
       return []
     }
 

Plugins/Enlighter/XcodeSPMCompat.swift

@@ -30,6 +30,26 @@ extension XcodeProject {
   }
 }
 
+extension Collection where Element == Path {
+    func longestPathPrefix() -> Path {
+        let sorted = sorted() { $0.string.count < $1.string.count }
+        guard let short = sorted.first,
+              let long = sorted.last
+        else { return first ?? Path("/tmp/") }
+
+        let shortComponents = short.string.split(separator: "/")
+        let longComponents = long.string.split(separator: "/")
+
+        for (i, c) in shortComponents.enumerated() {
+            if c != longComponents[i] {
+                return Path("/").appending(shortComponents.prefix(i).map({ String($0) }))
+            }
+        }
+
+        return short
+    }
+}
+
 extension XcodeTarget {
 
   var name : String { product?.name ?? displayName }
@@ -54,7 +74,13 @@ extension XcodeTarget {
     if let matching = directories.first(where: { $0.string.hasSuffix(match) }) {
       return matching
     }
+    let innerMatch = "/" + name + "/"
+    let matching = directories.filter({ $0.string.contains(innerMatch) })
+    if matching.count > 0 {
+      return matching.longestPathPrefix()
+    }
     // give up and use first :-)
+    print("Could not infer target root, using an arbitrary directory")
     return directories[0]
   }