From 5d8582316770fc6555f019a03183bb9a00f87175 Mon Sep 17 00:00:00 2001
From: Peter Butzhammer <peter.butzhammer@evopro-ag.de>
Date: Thu, 8 Feb 2024 18:06:55 +0100
Subject: [PATCH] Verify data types

---
 Sharp7.Rx/S7VariableNameParser.cs |  7 ++++---
 Sharp7.Rx/Sharp7Plc.cs            | 18 ++++++++++++------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/Sharp7.Rx/S7VariableNameParser.cs b/Sharp7.Rx/S7VariableNameParser.cs
index 38cecc3..b53fcc9 100644
--- a/Sharp7.Rx/S7VariableNameParser.cs
+++ b/Sharp7.Rx/S7VariableNameParser.cs
@@ -1,4 +1,5 @@
-using System.Globalization;
+#nullable enable
+using System.Globalization;
 using System.Text.RegularExpressions;
 using Sharp7.Rx.Enums;
 using Sharp7.Rx.Interfaces;
@@ -7,8 +8,8 @@ namespace Sharp7.Rx;
 
 internal class S7VariableNameParser : IS7VariableNameParser
 {
-    private static readonly Regex regex = new Regex(@"^(?<operand>db)(?<dbNo>\d+)\.?(?<type>[a-z]+)(?<start>\d+)(\.(?<bitOrLength>\d+))?$",
-                                                    RegexOptions.IgnoreCase | RegexOptions.Compiled | RegexOptions.CultureInvariant);
+    private static readonly Regex regex = new(@"^(?<operand>db)(?<dbNo>\d+)\.?(?<type>[a-z]+)(?<start>\d+)(\.(?<bitOrLength>\d+))?$",
+                                              RegexOptions.IgnoreCase | RegexOptions.Compiled | RegexOptions.CultureInvariant);
 
     private static readonly IReadOnlyDictionary<string, DbType> types = new Dictionary<string, DbType>(StringComparer.OrdinalIgnoreCase)
     {
diff --git a/Sharp7.Rx/Sharp7Plc.cs b/Sharp7.Rx/Sharp7Plc.cs
index 46936ef..ec6504a 100644
--- a/Sharp7.Rx/Sharp7Plc.cs
+++ b/Sharp7.Rx/Sharp7Plc.cs
@@ -77,8 +77,7 @@ public class Sharp7Plc : IPlc
     {
         return Observable.Create<TValue>(observer =>
         {
-            var address = varaibleNameParser.Parse(variableName);
-            if (address == null) throw new ArgumentException("Input variable name is not valid", nameof(variableName));
+            var address = ParseAndVerify(variableName, typeof(TValue));
 
             var disp = new CompositeDisposable();
             var disposeableContainer = multiVariableSubscriptions.GetOrCreateObservable(variableName);
@@ -103,6 +102,15 @@ public class Sharp7Plc : IPlc
         });
     }
 
+    private S7VariableAddress ParseAndVerify(string variableName, Type type)
+    {
+        var address = varaibleNameParser.Parse(variableName);
+        if (!address.MatchesType(type))
+            throw new DataTypeMissmatchException($"Address \"{variableName}\" does not match type {type}.", type, address);
+
+        return address;
+    }
+
     public Task<TValue> GetValue<TValue>(string variableName)
     {
         return GetValue<TValue>(variableName, CancellationToken.None);
@@ -117,8 +125,7 @@ public class Sharp7Plc : IPlc
 
     public async Task<TValue> GetValue<TValue>(string variableName, CancellationToken token)
     {
-        var address = varaibleNameParser.Parse(variableName);
-        if (address == null) throw new ArgumentException("Input variable name is not valid", nameof(variableName));
+        var address = ParseAndVerify(variableName, typeof(TValue));
 
         var data = await s7Connector.ReadBytes(address.Operand, address.Start, address.Length, address.DbNr, token);
         return S7ValueConverter.ReadFromBuffer<TValue>(data, address);
@@ -150,8 +157,7 @@ public class Sharp7Plc : IPlc
 
     public async Task SetValue<TValue>(string variableName, TValue value, CancellationToken token)
     {
-        var address = varaibleNameParser.Parse(variableName);
-        if (address == null) throw new ArgumentException("Input variable name is not valid", "variableName");
+        var address = ParseAndVerify(variableName, typeof(TValue));
 
         if (typeof(TValue) == typeof(bool))
         {