extract writeGroupWithTesters from existing map func

Author: DechengMa

Sources/AppStoreConnectCLI/Files/BetaGroupResourceProcessor.swift

@@ -41,19 +41,26 @@ struct BetaGroupResourceProcessor: ResourceProcessor {
 
         try folder.files.forEach { try $0.delete() }
 
-        let betaGroups = try betaGroupWithTesters.map { (group: BetaGroup, testers: [BetaTester]) -> BetaGroup in
-            let testersFile = try folder
-                .createFile(named: "\(group.formattedFileName)_beta-testers.csv")
+        let betaGroups = try betaGroupWithTesters.map {
+            try self.write(group: $0, with: $1, in: folder)
+        }
 
-            try testersFile.write(testers.renderAsCSV())
+        try write(betaGroups)
+    }
 
-            var group = group
+    private func write(
+        group: BetaGroup,
+        with testers: [BetaTester],
+        in folder: Folder
+    ) throws -> BetaGroup {
+        let testersFile = try folder
+            .createFile(named: "\(group.formattedFileName)_beta-testers.csv")
 
-            group.testers = testersFile.path
+        try testersFile.write(testers.renderAsCSV())
 
-            return group
-        }
+        var group = group
+        group.testers = testersFile.path
 
-        try write(betaGroups)
+        return group
     }
 }