diff --git a/designer-base/src/test/java/com/fr/design/gui/itree/filetree/FileNodeConstantsTest.java b/designer-base/src/test/java/com/fr/design/gui/itree/filetree/FileNodeConstantsTest.java
new file mode 100644
index 000000000..67f082456
--- /dev/null
+++ b/designer-base/src/test/java/com/fr/design/gui/itree/filetree/FileNodeConstantsTest.java
@@ -0,0 +1,51 @@
+package com.fr.design.gui.itree.filetree;
+
+import com.fr.base.extension.FileExtension;
+import com.fr.base.io.BaseBook;
+import com.fr.design.ExtraDesignClassManager;
+import com.fr.design.mainframe.AbstractAppProvider;
+import com.fr.design.mainframe.App;
+import com.fr.design.mainframe.JTemplate;
+import com.fr.file.FILE;
+import com.fr.stable.fun.mark.Mutable;
+import org.easymock.EasyMock;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Created by alex sung on 2019/7/25.
+ */
+public class FileNodeConstantsTest {
+    @Test
+    public void supportFileTypesTest(){
+        ExtraDesignClassManager extra = EasyMock.mock(ExtraDesignClassManager.class);
+        Set<Mutable> apps = new HashSet<Mutable>(){{add(new MockCptxApp());}};
+        EasyMock.expect(extra.getArray(App.MARK_STRING)).andReturn(apps).anyTimes();
+        EasyMock.replay(extra);
+
+        Assert.assertEquals(1, extra.getArray(App.MARK_STRING).size());
+        App app = (App) extra.getArray(App.MARK_STRING).iterator().next();
+        Assert.assertEquals("cptx", app.defaultExtensions()[0]);
+    }
+
+    private class MockCptxApp extends AbstractAppProvider{
+        @Override
+        public String[] defaultExtensions() {
+            return new String[] {FileExtension.CPTX.getExtension()};
+        }
+
+        @Override
+        public JTemplate openTemplate(FILE tplFile) {
+            return null;
+        }
+
+        @Override
+        public BaseBook asIOFile(FILE tplFile) {
+            return null;
+        }
+    }
+
+}