feat(test): test arguments in Main class

app/src/test/java/MainTest.java

@@ -0,0 +1,75 @@
+import org.junit.jupiter.api.*;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MainTest {
+
+	// File handling variables
+	@TempDir
+	static Path tempDir;
+	static Path tempFile;
+	
+	// PrintStream (to capture the console output)
+	private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+	private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();
+	
+	// Save the old PrintStreams
+	private final PrintStream oldOut = System.out;
+	private final PrintStream oldErr = System.err;
+	
+	@BeforeAll
+	static void start() throws IOException {
+		tempFile = Files.createFile(tempDir.resolve("testing.txt"));
+	}
+	
+	@BeforeEach
+	void setUp() {
+		// Create new PrintStream to capture console outputs
+		System.setOut(new PrintStream(outContent));
+		System.setErr(new PrintStream(errContent));
+	}
+	
+	@AfterEach
+	void tearDown() {
+		// Reset PrintStream to original
+		System.setOut(oldOut);
+		System.setErr(oldErr);
+	}
+	
+	@Test
+	@DisplayName("No arguments provided")
+	void noArguments() {
+		String[] arguments = new String[0];
+		
+		Main.main(arguments);
+		
+		// Check that the program quit at the expected point, with expected output
+		assertEquals("Invalid arguments, you need to define the text file to read from!\n", outContent.toString());
+	}
+	
+	@Test
+	@DisplayName("Too many arguments provided")
+	void tooManyArguments() {
+		String[] arguments = new String[2];
+		// Simulating a potential typo of the path with a space
+		arguments[0] = "/path/to/";
+		arguments[1] = "file.txt";
+		
+		Main.main(arguments);
+
+		// Check that the program quit at the expected point, with expected output
+		assertEquals("Invalid arguments, you need to define the text file to read from!\n", outContent.toString());
+	}
+
+	@Test
+	@DisplayName("Normal test run")
+	void normalRun() {
+	}
+}