Extract method for creating a retry strategy.

Author: sjp

src/coverlet.core/Helpers/InstrumentationHelper.cs

@@ -63,13 +63,7 @@ public static void RestoreOriginalModule(string module, string identifier)
 
             // Restore the original module - retry up to 10 times, since the destination file could be locked
             // See: https://github.com/tonerdo/coverlet/issues/25
-            var currentSleep = 6;
-            TimeSpan retryStrategy()
-            {
-                var sleep = TimeSpan.FromMilliseconds(currentSleep);
-                currentSleep *= 2;
-                return sleep;
-            }
+            var retryStrategy = CreateRetryStrategy();
 
             RetryHelper.Retry(() => {
                 File.Copy(backupPath, module, true);
@@ -81,13 +75,7 @@ public static IEnumerable<string> ReadHitsFile(string path)
         {
             // Retry hitting the hits file - retry up to 10 times, since the file could be locked
             // See: https://github.com/tonerdo/coverlet/issues/25
-            var currentSleep = 6;
-            TimeSpan retryStrategy()
-            {
-                var sleep = TimeSpan.FromMilliseconds(currentSleep);
-                currentSleep *= 2;
-                return sleep;
-            }
+            var retryStrategy = CreateRetryStrategy();
 
             return RetryHelper.Do(() => File.ReadLines(path), retryStrategy, 10);
         }
@@ -96,13 +84,7 @@ public static void DeleteHitsFile(string path)
         {
             // Retry hitting the hits file - retry up to 10 times, since the file could be locked
             // See: https://github.com/tonerdo/coverlet/issues/25
-            var currentSleep = 6;
-            TimeSpan retryStrategy()
-            {
-                var sleep = TimeSpan.FromMilliseconds(currentSleep);
-                currentSleep *= 2;
-                return sleep;
-            }
+            var retryStrategy = CreateRetryStrategy();
 
             RetryHelper.Retry(() => File.Delete(path), retryStrategy, 10);
         }
@@ -164,6 +146,18 @@ private static string GetBackupPath(string module, string identifier)
                 Path.GetFileNameWithoutExtension(module) + "_" + identifier + ".dll"
             );
         }
+
+        private static Func<TimeSpan> CreateRetryStrategy(int initialSleepSeconds = 6)
+        {
+            TimeSpan retryStrategy()
+            {
+                var sleep = TimeSpan.FromMilliseconds(initialSleepSeconds);
+                initialSleepSeconds *= 2;
+                return sleep;
+            }
+
+            return retryStrategy;
+        }
     }
 }