added some test cases

src/main/java/de/neemann/digital/draw/graphics/text/formatter/GraphicsFormatter.java

@@ -149,7 +149,7 @@ public final class GraphicsFormatter {
         }
     }
 
-    private final static class TextFragment extends Fragment {
+    final static class TextFragment extends Fragment {
         private final String text;
         private final Font font;
 
@@ -287,7 +287,7 @@ public final class GraphicsFormatter {
         /**
          * Must set the size of the given fragment by calling the {@link Fragment#set(int, int, int)} method.
          *
-         * @param fragment fragment which size
+         * @param fragment fragment which size is requested
          * @param font     the used font
          * @param str      the string to measure
          */

src/test/java/de/neemann/digital/draw/graphics/text/ParserTest.java

@@ -1,9 +1,21 @@
 package de.neemann.digital.draw.graphics.text;
 
+import de.neemann.digital.draw.graphics.text.text.Simple;
+import de.neemann.digital.draw.graphics.text.text.Text;
 import junit.framework.TestCase;
 
 public class ParserTest extends TestCase {
 
+
+    public void testPlainString() throws ParseException {
+        Text t = new Parser("Q").parse();
+        assertTrue(t instanceof Simple);
+        assertEquals("Q", ((Simple) t).getText());
+        t = new Parser("In").parse();
+        assertTrue(t instanceof Simple);
+        assertEquals("In", ((Simple) t).getText());
+    }
+
     public void testSimple() throws ParseException {
         assertEquals("Decorate{Q_{i}, OVERLINE}", new Parser("~{Q_{i}}").parse().toString());
         assertEquals("Decorate{Q, OVERLINE}_{i}", new Parser("~Q_{i}").parse().toString());

src/test/java/de/neemann/digital/draw/graphics/text/formatter/GraphicsFormatterTest.java

@@ -0,0 +1,26 @@
+package de.neemann.digital.draw.graphics.text.formatter;
+
+import de.neemann.digital.draw.graphics.text.text.Simple;
+import de.neemann.digital.draw.graphics.text.text.Text;
+import junit.framework.TestCase;
+
+import java.awt.*;
+
+public class GraphicsFormatterTest extends TestCase {
+
+    /**
+     * Ensures that a simple string leads to the simplest text fragment
+     */
+    public void testSimple() throws GraphicsFormatter.FormatterException {
+        Text t = new Simple("Q");
+        GraphicsFormatter.Fragment f = GraphicsFormatter.createFragment(
+                (fragment, font, str) -> {
+                    assertEquals("Q", str);
+                    fragment.set(10, 10, 5);
+                },
+                Font.getFont("Arial"), t);
+
+        assertTrue(f instanceof GraphicsFormatter.TextFragment);
+    }
+
+}