From 178b1d370de3ad4f04835692ac27674819f7a358 Mon Sep 17 00:00:00 2001
From: "david@DAVID-PC" <3200210+davidjenni@users.noreply.github.com>
Date: Tue, 25 Nov 2025 14:30:22 -0800
Subject: [PATCH 1/2] fix: /diag behaves like a proper boolean switch

before fix, order of arguments mattered:
- unless /diag is last argument, it is ignored; and the following
  argument is swalloed silently

/diag /l gv.log  -> diagnostic switch is ignored, no log file is created
/l console /diag -> diagnostic output is emitted to console
/l gv.log /diag  -> diagnostic output is emitted to log file
---
 src/GitVersion.App/ArgumentParser.cs           | 6 +-----
 src/GitVersion.App/ArgumentParserExtensions.cs | 2 +-
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/src/GitVersion.App/ArgumentParser.cs b/src/GitVersion.App/ArgumentParser.cs
index 1f85a1b3d2..d7b4df31bc 100644
--- a/src/GitVersion.App/ArgumentParser.cs
+++ b/src/GitVersion.App/ArgumentParser.cs
@@ -212,11 +212,7 @@ private static bool ParseSwitches(Arguments arguments, string? name, IReadOnlyLi
 
         if (name.IsSwitch("diag"))
         {
-            if (value?.IsTrue() != false)
-            {
-                arguments.Diag = true;
-            }
-
+            arguments.Diag = true;
             return true;
         }
 
diff --git a/src/GitVersion.App/ArgumentParserExtensions.cs b/src/GitVersion.App/ArgumentParserExtensions.cs
index 7d0dade040..286849c44b 100644
--- a/src/GitVersion.App/ArgumentParserExtensions.cs
+++ b/src/GitVersion.App/ArgumentParserExtensions.cs
@@ -73,7 +73,7 @@ public bool IsSwitch(string switchName)
 
         public bool ArgumentRequiresValue(int argumentIndex)
         {
-            var booleanArguments = new[] { "updateassemblyinfo", "ensureassemblyinfo", "nofetch", "nonormalize", "nocache", "allowshallow" };
+            var booleanArguments = new[] { "updateassemblyinfo", "ensureassemblyinfo", "nofetch", "nonormalize", "nocache", "allowshallow", "diag" };
 
             var argumentMightRequireValue = !booleanArguments.Contains(singleArgument[1..], StringComparer.OrdinalIgnoreCase);
 

From 0b5484647c12494e690278d71115b2241482b0cc Mon Sep 17 00:00:00 2001
From: "david@DAVID-PC" <3200210+davidjenni@users.noreply.github.com>
Date: Tue, 25 Nov 2025 14:50:20 -0800
Subject: [PATCH 2/2] test: -diag switch order in arg list doesn't matter

---
 src/GitVersion.App.Tests/ArgumentParserTests.cs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/GitVersion.App.Tests/ArgumentParserTests.cs b/src/GitVersion.App.Tests/ArgumentParserTests.cs
index 42e7c36304..911c1f0812 100644
--- a/src/GitVersion.App.Tests/ArgumentParserTests.cs
+++ b/src/GitVersion.App.Tests/ArgumentParserTests.cs
@@ -636,6 +636,21 @@ public void AllowshallowTrueWhenDefined()
         arguments.AllowShallow.ShouldBe(true);
     }
 
+    [Test]
+    public void DiagTrueWhenDefined()
+    {
+        var arguments = this.argumentParser.ParseArguments("-diag");
+        arguments.Diag.ShouldBe(true);
+    }
+
+    [Test]
+    public void DiagAndLogToConsoleIsNotIgnored()
+    {
+        var arguments = this.argumentParser.ParseArguments("-diag -l console");
+        arguments.Diag.ShouldBe(true);
+        arguments.LogFilePath.ShouldBe("console");
+    }
+
     [Test]
     public void OtherArgumentsCanBeParsedBeforeNofetch()
     {