bullet format file errors

Author: LePips

Plugins/PluginsShared/PluginError.swift

@@ -37,7 +37,7 @@ enum PluginError: Swift.Error, CustomStringConvertible, LocalizedError {
             let targetNames = targetNames.joined(separator: ", ", lastSeparator: " and ")
             return "Found no targets with names \(targetNames)."
         case .fileErrors(let fileErrors):
-            return "Issues with required files: \(fileErrors.map(\.description).joined(separator: ", and"))."
+            return "Issues with required files:\n\(fileErrors.map { $0 .description.prepended("- ") }.joined(separator: "\n"))."
         }
     }
 

Plugins/PluginsShared/PluginUtils.swift

@@ -97,3 +97,9 @@ extension Array where Element == String {
         return "\(self.dropLast().joined(separator: separator))\(lastSeparator)\(self.last!)"
     }
 }
+
+extension String {
+    func prepended(_ prefix: String) -> String {
+        return prefix + self
+    }
+}