Restore 100% coverage

The coverlet 10.0.1 upgrade spotted a branch that was not 100% covered.

Author: 0xced

tests/Log4NetTextFormatterTest.CallerInvalidFormat.verified.xml

@@ -0,0 +1,3 @@
+<log4net:event timestamp="2003-01-04T15:09:26.535+01:00" level="INFO" xmlns:log4net="http://logging.apache.org/log4net/schemas/log4net-events-1.2/">
+  <log4net:message><![CDATA[Hello from Serilog]]></log4net:message>
+</log4net:event>

tests/Log4NetTextFormatterTest.cs

@@ -684,6 +684,22 @@ public Task Caller()
         return Verify(output);
     }
 
+    [Fact]
+    public Task CallerWithFile()
+    {
+        // Arrange
+        using var output = new StringWriter();
+        var logEvent = CreateLogEvent(properties: new LogEventProperty("Caller", new ScalarValue("Fully.Qualified.ClassName.MethodName(System.String) /Absolute/Path/To/FileName.cs:123")));
+
+        var formatter = new Log4NetTextFormatter();
+
+        // Act
+        formatter.Format(logEvent, output);
+
+        // Assert
+        return Verify(output);
+    }
+
     [Fact]
     public Task CallerNonScalar()
     {
@@ -701,11 +717,11 @@ public Task CallerNonScalar()
     }
 
     [Fact]
-    public Task CallerWithFile()
+    public Task CallerInvalidFormat()
     {
         // Arrange
         using var output = new StringWriter();
-        var logEvent = CreateLogEvent(properties: new LogEventProperty("Caller", new ScalarValue("Fully.Qualified.ClassName.MethodName(System.String) /Absolute/Path/To/FileName.cs:123")));
+        var logEvent = CreateLogEvent(properties: new LogEventProperty("Caller", new ScalarValue("NotFullyQualifiedMethodName")));
 
         var formatter = new Log4NetTextFormatter();