Add test for PGPainlessCLI main class

pgpainless-sop/src/test/java/org/pgpainless/sop/MainClassTest.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2021 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.pgpainless.sop;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class MainClassTest {
+
+    private static OutputStream originalSout;
+
+    @BeforeAll
+    public static void saveOriginalSout() {
+        originalSout = System.out;
+    }
+
+    @Test
+    public void testMainByVersionCommand() {
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        System.setOut(new PrintStream(out));
+        PGPainlessCLI.main(new String[] {"version"});
+        String version = out.toString();
+        assertTrue(version.startsWith("PGPainlessCLI"));
+    }
+
+    @AfterAll
+    public static void restoreOriginalSout() {
+        System.setOut(new PrintStream(originalSout));
+    }
+}