added first console commands (to generate java code with or without s…

pom.xml

@@ -132,6 +132,11 @@ SOFTWARE.
       <version>3.0</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>info.picocli</groupId>
+      <artifactId>picocli</artifactId>
+      <version>4.7.6</version>
+    </dependency>
   </dependencies>
   <build>
     <plugins>

src/main/java/com/github/lombrozo/jsmith/commandline/RandomJavaCodeCommand.java

@@ -0,0 +1,26 @@
+package com.github.lombrozo.jsmith.commandline;
+
+import com.github.lombrozo.jsmith.RandomJavaClass;
+import picocli.CommandLine;
+
+/**
+ * @todo #18: Add more console commands and also write tests for them.
+ */
+
+@CommandLine.Command(name = "randomjavacode", description = "Generates a random Java code", mixinStandardHelpOptions = true)
+public class RandomJavaCodeCommand implements Runnable{
+
+    @CommandLine.Option(names = {"-s", "--seed"}, description = "seed for random generation", defaultValue = "-1")
+    long seed;
+
+    @Override
+    public void run() {
+        RandomJavaClass clazz;
+        if (seed == -1) {
+            clazz = new RandomJavaClass();
+        } else {
+            clazz = new RandomJavaClass(seed);
+        }
+        System.out.print(clazz.src());
+    }
+}

src/test/java/com/github/lombrozo/jsmith/it/ConsoleCommandIT.java

@@ -0,0 +1,52 @@
+package com.github.lombrozo.jsmith.it;
+
+import com.github.lombrozo.jsmith.commandline.RandomJavaCodeCommand;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.RepeatedTest;
+import picocli.CommandLine;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.util.Random;
+import java.util.logging.Logger;
+
+/**
+ * This test checks how CLI works
+ **/
+public class ConsoleCommandIT {
+    private final ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    private final PrintStream originalOut = System.out;
+    private static final Logger logger = Logger.getLogger(ConsoleCommandIT.class.getName());
+
+    @RepeatedTest(10)
+    public void generatesJavaCode() {
+        CommandLine cmd = new CommandLine(new RandomJavaCodeCommand());
+        System.setOut(new PrintStream(outputStream));
+        String randomExecutionArgs = getRandomExecuteArgs();
+        int exitCode;
+        if (randomExecutionArgs != null) {
+            exitCode = cmd.execute(randomExecutionArgs);
+        } else {
+            exitCode = cmd.execute();
+        }
+        System.setOut(originalOut);
+        String executionResult = outputStream.toString();
+
+        Assertions.assertEquals(0, exitCode, "We expect the command to complete correctly.");
+        Assertions.assertFalse(executionResult.isEmpty(), "We expect the output to be non-empty.");
+        logger.info("Generated code: " + "\n-----\n" + executionResult + "\n-----\n");
+    }
+
+    private String getRandomExecuteArgs() {
+        Random random = new Random();
+        boolean needArgs = random.nextBoolean();
+        long seed;
+        if (needArgs) {
+            seed = random.nextLong();
+            logger.info("Random seed: " + seed);
+            return "-s=" + seed;
+        } else {
+            return null;
+        }
+    }
+}