Fix: Allow dashes in SQL Server instance names (#27)

- Updated InstanceName and InstanceNameEx regex patterns in RegexHelper.cs
  to include the dash/hyphen character (\-)
- Added two test cases to verify instance names with dashes work correctly
- Fixes issue where instance names like "My-TestInstance" were incorrectly
  rejected as invalid

This resolves the parsing error when using instance names containing dashes,
which are valid according to SQL Server naming rules.

Fixes #13

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Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

Author: potatoqualitee

project/dbatools.Tests/Parameter/DbaInstanceParamaterTest.cs

@@ -202,5 +202,41 @@ public void TestLocalhost(string localhost)
             Assert.AreEqual(SqlConnectionProtocol.Any, dbaInstanceParamater.NetworkProtocol);
             Assert.IsTrue(dbaInstanceParamater.IsLocalHost);
         }
+
+        /// <summary>
+        /// Checks that instance names with dashes are properly parsed
+        /// </summary>
+        [TestMethod]
+        public void TestInstanceNameWithDash()
+        {
+            var dbaInstanceParamater = new DbaInstanceParameter("My-Instance.domain.local\\My-TestInstance");
+
+            Assert.AreEqual("My-Instance.domain.local", dbaInstanceParamater.ComputerName);
+            Assert.AreEqual("My-TestInstance", dbaInstanceParamater.InstanceName);
+            Assert.AreEqual("My-Instance.domain.local\\My-TestInstance", dbaInstanceParamater.FullName);
+            Assert.AreEqual("My-Instance.domain.local\\My-TestInstance", dbaInstanceParamater.FullSmoName);
+            Assert.AreEqual("[My-Instance.domain.local]", dbaInstanceParamater.SqlComputerName);
+            Assert.AreEqual("[My-TestInstance]", dbaInstanceParamater.SqlInstanceName);
+            Assert.AreEqual("[My-Instance.domain.local\\My-TestInstance]", dbaInstanceParamater.SqlFullName);
+            Assert.IsFalse(dbaInstanceParamater.IsConnectionString);
+        }
+
+        /// <summary>
+        /// Checks that server names with dashes work correctly (regression test)
+        /// </summary>
+        [TestMethod]
+        public void TestServerNameWithDash()
+        {
+            var dbaInstanceParamater = new DbaInstanceParameter("My-Instance.domain.local\\MyTestInstance");
+
+            Assert.AreEqual("My-Instance.domain.local", dbaInstanceParamater.ComputerName);
+            Assert.AreEqual("MyTestInstance", dbaInstanceParamater.InstanceName);
+            Assert.AreEqual("My-Instance.domain.local\\MyTestInstance", dbaInstanceParamater.FullName);
+            Assert.AreEqual("My-Instance.domain.local\\MyTestInstance", dbaInstanceParamater.FullSmoName);
+            Assert.AreEqual("[My-Instance.domain.local]", dbaInstanceParamater.SqlComputerName);
+            Assert.AreEqual("[MyTestInstance]", dbaInstanceParamater.SqlInstanceName);
+            Assert.AreEqual("[My-Instance.domain.local\\MyTestInstance]", dbaInstanceParamater.SqlFullName);
+            Assert.IsFalse(dbaInstanceParamater.IsConnectionString);
+        }
     }
 }

project/dbatools/Utility/RegexHelper.cs

@@ -53,12 +53,12 @@ public static class RegexHelper
         /// <summary>
         /// Will match a mostly valid instance name.
         /// </summary>
-        public static string InstanceName = @"^[\p{L}&_#][\p{L}\d\$#_]{0,15}$";
+        public static string InstanceName = @"^[\p{L}&_#][\p{L}\d\$#_\-]{0,15}$";
 
         /// <summary>
         /// Will match any instance of a mostly valid instance name.
         /// </summary>
-        public static string InstanceNameEx = @"[\p{L}&_#][\p{L}\d\$#_]{0,15}";
+        public static string InstanceNameEx = @"[\p{L}&_#][\p{L}\d\$#_\-]{0,15}";
 
         /// <summary>
         /// Matches a word against the list of officially reserved keywords