small code improvements

0-Plugin/src/main/java/main/CommandHandler.java

@@ -3,7 +3,6 @@ package main;
 import category.CategoryRepository;
 import category.CategoryUseCase;
 import category.RandomCategoryIdGenerator;
-import cli.CliError;
 import cli.Subcommand;
 import cli.category.CategoryCliAdapter;
 import cli.category.CategoryCommands;
@@ -42,20 +41,27 @@ public class CommandHandler {
 
 	public void executeCommand(String[] args) {
 
-		if(args.length == 0){
+		if (args.length == 0) {
-			//TODO: print usage
+			printUsage();
+			return;
 		}
 
 		var command = subcommands.get(args[0]);
 
 		if (command == null) {
-			throw new CliError("Unknown Command");
+			System.out.println("Unkown subcommand!");
+			printUsage();
 		}
 
 		var output = command.executeSubcommand(Arrays.copyOfRange(args, 1, args.length));
 		System.out.println(output);
 	}
 
+	private void printUsage() {
+		System.out.println("All available subcommands: ");
+		subcommands.forEach((name, subcommand) -> System.out.println(System.lineSeparator() + subcommand.getUsage()));
+	}
+
 	private void addSubcommands() {
 
 		CategoryRepository categoryRepository =

0-Plugin/src/main/java/persistence/GenericCSVDAO.java

@@ -34,7 +34,7 @@ public class GenericCSVDAO<T extends CSVSerializable> implements GenericDAO<T> {
 		}
 	}
 
-	public Set<T> getALl() {
+	public Set<T> getAll() {
 		var lines = new ArrayList<String>();
 		try (BufferedReader br = new BufferedReader(new FileReader(this.file))) {
 			for (String line; (line = br.readLine()) != null; ) {
@@ -53,7 +53,7 @@ public class GenericCSVDAO<T extends CSVSerializable> implements GenericDAO<T> {
 
 	@Override
 	public void remove(T value) {
-		var allEntities = this.getALl();
+		var allEntities = this.getAll();
 		this.removeAll();
 
 		allEntities.stream().filter(entity -> !entity.equals(value)).forEach(this::add);

0-Plugin/src/test/java/persistence/GenericCSVDAOTest.java

@@ -36,10 +36,10 @@ class GenericCSVDAOTest {
 
 	@Test
 	public void addWorks() throws IOException {
-		assertEquals(0, sut.getALl().size());
+		assertEquals(0, sut.getAll().size());
 
 		CategoryEntity entityToAdd = addDummyEntity("categoryName", 99);
-		var foundEntity = sut.getALl().stream().findFirst().orElseThrow();
+		var foundEntity = sut.getAll().stream().findFirst().orElseThrow();
 
 		assertEquals(entityToAdd, foundEntity);
 	}
@@ -50,7 +50,7 @@ class GenericCSVDAOTest {
 
 		sut.remove(entityToAdd);
 
-		assertEquals(0, sut.getALl().size());
+		assertEquals(0, sut.getAll().size());
 	}
 
 
@@ -58,10 +58,10 @@ class GenericCSVDAOTest {
 	public void removeAllWorks() throws IOException {
 		addDummyEntity("categoryName1", 101);
 		addDummyEntity("categoryName2", 102);
-		assertEquals(2, sut.getALl().size());
+		assertEquals(2, sut.getAll().size());
 		sut.removeAll();
 
-		assertEquals(0, sut.getALl().size());
+		assertEquals(0, sut.getAll().size());
 	}
 
 	private CategoryEntity addDummyEntity(String categoryName, int id) {

1-Adapter/src/main/java/persistence/GenericDAO.java

@@ -1,13 +1,10 @@
 package persistence;
 
-import persistence.category.CategoryEntity;
-
 import java.util.Set;
-import java.util.function.Function;
 
 public interface GenericDAO<T> {
 
-	public Set<T> getALl();
+	public Set<T> getAll();
 
 	void remove(T value);
 

1-Adapter/src/main/java/persistence/category/CSVCategoryPersistenceAdapter.java

@@ -19,7 +19,7 @@ public class CSVCategoryPersistenceAdapter implements PersistenceAdapter<Categor
 
 	@Override
 	public Set<Category> getAll() {
-		return categoryDAO.getALl().stream().map(CategoryEntity::toCategory).collect(Collectors.toSet());
+		return categoryDAO.getAll().stream().map(CategoryEntity::toCategory).collect(Collectors.toSet());
 	}
 
 	@Override

1-Adapter/src/main/java/persistence/customTags/CSVCustomTagMatcherPersistenceAdapter.java

@@ -18,7 +18,7 @@ public class CSVCustomTagMatcherPersistenceAdapter implements PersistenceAdapter
 	@Override
 	public Set<CustomTagMatcher> getAll() {
 		return customTagMatcherDAO
-				.getALl()
+				.getAll()
 				.stream()
 				.map(CustomTagMatcherEntity::toCustomTagMatcher)
 				.collect(Collectors.toSet());

1-Adapter/src/main/java/persistence/link/CSVLinkPersistenceAdapter.java

@@ -17,7 +17,7 @@ public class CSVLinkPersistenceAdapter implements PersistenceAdapter<Link> {
 
 	@Override
 	public Set<Link> getAll() {
-		return linkDAO.getALl().stream().map(LinkEntity::toLink).collect(Collectors.toSet());
+		return linkDAO.getAll().stream().map(LinkEntity::toLink).collect(Collectors.toSet());
 	}
 
 	@Override

2-Application/src/main/java/link/LinkDto.java

@@ -8,4 +8,12 @@ import java.util.Set;
 
 public record LinkDto(Username creator, LinkUrl url, Set<Category> categories, Set<Tag> tags) {
 
+	@Override
+	public String toString() {
+		return
+				url +
+						" by " + creator +
+						" categories: " + categories +
+						" tags:" + tags;
+	}
 }

3-Domain/src/main/java/tag/Tag.java

@@ -11,11 +11,6 @@ public class Tag {
 		this.name = name;
 	}
 
-	public Tag(TagName name, String additionalData) {
-		this.name = name;
-		this.additionalData = Optional.ofNullable(additionalData);
-	}
-
 	public Tag(TagName name, Optional<String> additionalData) {
 		this.name = name;
 		this.additionalData = additionalData;
@@ -35,6 +30,7 @@ public class Tag {
 	}
 
 	public Tag addAdditionalData(String additionalData) {
-		return new Tag(this.name, additionalData);
+		this.additionalData = Optional.of(additionalData);
+		return this;
 	}
 }