From 020c17896aa8169dd3b42b6d2582f107cb4334c1 Mon Sep 17 00:00:00 2001
From: EugeneTes <meelstorm@gmail.com>
Date: Thu, 3 Sep 2026 12:13:41 +0200
Subject: [PATCH] register printer id 0x20 as POS895 across the three dispatch
 points

Claude-Session: https://claude.ai/code/session_01E6N3P4nSZLtp4BC2LXVref
---
 .../PrinterRegistrationTests.cs               | 85 +++++++++++++++++++
 Inspectron.Epson/DiscoveryService.cs          |  1 +
 .../Printers/PrinterWrapperFactory.cs         |  2 +
 .../Printers/Utils/ReceiptConverterFactory.cs |  1 +
 4 files changed, 89 insertions(+)
 create mode 100644 Inspectron.Epson.Tests/PrinterRegistrationTests.cs

diff --git a/Inspectron.Epson.Tests/PrinterRegistrationTests.cs b/Inspectron.Epson.Tests/PrinterRegistrationTests.cs
new file mode 100644
index 0000000..6561dd3
--- /dev/null
+++ b/Inspectron.Epson.Tests/PrinterRegistrationTests.cs
@@ -0,0 +1,85 @@
+using Inspectron.Epson.PrintServer.Printers;
+using Inspectron.Epson.PrintServer.Printers.Utils;
+
+namespace Inspectron.Epson.Tests;
+
+public class PrinterRegistrationTests
+{
+    [Fact]
+    public void WrapperFactory_returns_a_POS895_for_id_0x20()
+    {
+        var factory = new PrinterWrapperFactory();
+
+        var printer = factory.CreatePrinterFromId(0x20, new RecordingEpsonPrinter());
+
+        Assert.IsType<POS895>(printer);
+    }
+
+    [Fact]
+    public void WrapperFactory_still_returns_a_TM_T30III_for_id_0x01()
+    {
+        var factory = new PrinterWrapperFactory();
+
+        var printer = factory.CreatePrinterFromId(0x01, new RecordingEpsonPrinter());
+
+        Assert.IsType<TM_T30IIITranslated>(printer);
+    }
+
+    [Fact]
+    public void WorkareaTicket_uses_48_columns_for_the_POS895()
+    {
+        // The switch defaults to the 33-column TM-U220 layout. Without an
+        // explicit 0x20 case a POS895 prints kitchen tickets far too narrow -
+        // wrong, but not obviously broken.
+        //
+        // Both branches return the same converter type and only the constructor
+        // argument differs, so comparing types would pass even unfixed. Reading
+        // the private field is the only way to observe it.
+        var factory = new ReceiptConverterFactory();
+
+        var pos895 = factory.Create((int)ReceiptConverterFactory.EReceiptType.WorkareaTicket, 0x20);
+
+        Assert.Equal(48, LineWidthOf(pos895));
+    }
+
+    [Fact]
+    public void WorkareaTicket_still_uses_33_columns_for_the_narrow_printer()
+    {
+        var factory = new ReceiptConverterFactory();
+
+        var u220 = factory.Create((int)ReceiptConverterFactory.EReceiptType.WorkareaTicket, 0x13);
+
+        Assert.Equal(33, LineWidthOf(u220));
+    }
+
+    /// <summary>
+    /// Reads KitchenReceiptConverterAdapter._lineWidth. Brittle by design: if the
+    /// field is renamed this fails loudly rather than silently passing.
+    /// </summary>
+    private static int LineWidthOf(IReceiptConverter converter)
+    {
+        var field = converter.GetType().GetField("_lineWidth",
+            System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
+
+        Assert.NotNull(field);
+        return (int)field!.GetValue(converter)!;
+    }
+
+    [Fact]
+    public void Receipt_types_resolve_for_the_POS895()
+    {
+        var factory = new ReceiptConverterFactory();
+
+        foreach (var type in new[]
+                 {
+                     ReceiptConverterFactory.EReceiptType.Receipt,
+                     ReceiptConverterFactory.EReceiptType.WorkareaTicket,
+                     ReceiptConverterFactory.EReceiptType.OrdersOverview,
+                     ReceiptConverterFactory.EReceiptType.Invoice,
+                     ReceiptConverterFactory.EReceiptType.MoneyReturn
+                 })
+        {
+            Assert.NotNull(factory.Create((int)type, 0x20));
+        }
+    }
+}
diff --git a/Inspectron.Epson/DiscoveryService.cs b/Inspectron.Epson/DiscoveryService.cs
index cbbd9ee..c900e62 100644
--- a/Inspectron.Epson/DiscoveryService.cs
+++ b/Inspectron.Epson/DiscoveryService.cs
@@ -144,6 +144,7 @@ public class DiscoveryService : IDiscoveryService
             0x01 => "TM-T30III",
             0x0D => "TM-U220II",
             0x13 => "TM-U220II",
+            0x20 => "POS895",
             _ => $"Unknown (0x{printerId:X2})"
         };
     }
diff --git a/Inspectron.Epson/PrintServer/Printers/PrinterWrapperFactory.cs b/Inspectron.Epson/PrintServer/Printers/PrinterWrapperFactory.cs
index 62aa7a4..5835be3 100644
--- a/Inspectron.Epson/PrintServer/Printers/PrinterWrapperFactory.cs
+++ b/Inspectron.Epson/PrintServer/Printers/PrinterWrapperFactory.cs
@@ -14,6 +14,8 @@ public class PrinterWrapperFactory:IWrapperPrinterFactory
                 return new TM_U220IITranslated(epsonPrinter);
             case 0x01:
                 return new TM_T30IIITranslated(epsonPrinter);
+            case 0x20:
+                return new POS895(epsonPrinter);
             default:
                 throw new NotSupportedException($"Printer with ID {printerId:X2} is not supported.");
         }
diff --git a/Inspectron.Epson/PrintServer/Printers/Utils/ReceiptConverterFactory.cs b/Inspectron.Epson/PrintServer/Printers/Utils/ReceiptConverterFactory.cs
index 8c65f0d..8ec217f 100644
--- a/Inspectron.Epson/PrintServer/Printers/Utils/ReceiptConverterFactory.cs
+++ b/Inspectron.Epson/PrintServer/Printers/Utils/ReceiptConverterFactory.cs
@@ -15,6 +15,7 @@ public class ReceiptConverterFactory : IReceiptConverterFactory
             {
                 //0x01=>new BarReceiptConverterAdapter(48, 24),
                 0x01 => new KitchenReceipt.KitchenReceiptConverterAdapter(48, 24),
+                0x20 => new KitchenReceipt.KitchenReceiptConverterAdapter(48, 24),
                 _ => new KitchenReceipt.KitchenReceiptConverterAdapter(33, 20),
             },
             EReceiptType.NextCourse => new KitchenReceipt.KitchenReceiptConverterAdapter(33, 20),