add testConvertLinks and delete test file Calculator

src/application/ConvertTxtMdToHtml.java

@@ -8,7 +8,7 @@
 
 public final class ConvertTxtMdToHtml {
   // Private constructor to prevent instantiation
-  private ConvertTxtMdToHtml() {
+  public ConvertTxtMdToHtml() {
     // Hidden constructor
   }
 

src/junit/ConvertTxtMdToHtmlTest.java

@@ -9,6 +9,8 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintStream;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.*;
@@ -70,4 +72,27 @@ public void testConversionWithSimpleText() {
     }
   }
 
+  @Test
+    public void testConvertLinks() {
+        try {
+            // Create an instance of ConvertTxtMdToHtml
+            ConvertTxtMdToHtml converter = new ConvertTxtMdToHtml();
+
+            // Use reflection to access the private convertLinks method
+            Method convertLinksMethod = ConvertTxtMdToHtml.class.getDeclaredMethod("convertLinks", String.class);
+            convertLinksMethod.setAccessible(true);
+
+            // Test cases
+            String input1 = "This is a [link](https://example.com).";
+            String expectedOutput1 = "This is a <a href=\"https://example.com\">link</a>.";
+            assertEquals(expectedOutput1, convertLinksMethod.invoke(converter, input1));
+
+            // Add more test cases as needed
+
+        } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+            e.printStackTrace();
+            fail("Exception thrown during test: " + e.getMessage());
+        }
+    }
+
 }