Preserve order of added comments and tags

src/main/java/analyzer/Analysis.java

@@ -1,9 +1,9 @@
 package analyzer;
 
-import java.util.Set;
+import java.util.List;
 
-public record Analysis(Set<Comment> comments, String summary) {
+public record Analysis(List<Comment> comments, String summary) {
     public Analysis {
-        comments = Set.copyOf(comments);
+        comments = List.copyOf(comments);
     }
 }

src/main/java/analyzer/Exercise.java

@@ -8,15 +8,15 @@
 
 import java.io.File;
 import java.io.FileNotFoundException;
-import java.util.HashSet;
-import java.util.Set;
+import java.util.ArrayList;
+import java.util.List;
 
 public abstract class Exercise {
     private CompilationUnit compilationUnit;
 
     private String summary;
-    private final Set<Comment> comments = new HashSet<>();
-    private final Set<String> tags = new HashSet<>();
+    private final List<Comment> comments = new ArrayList<>();
+    private final List<String> tags = new ArrayList<>();
 
     protected Exercise(String directory, String solutionFile) {
         this(getSolutionFile(directory, solutionFile));
@@ -46,15 +46,19 @@ public final void parse() {
     abstract public void parse(CompilationUnit compilationUnit);
 
     protected void addComment(Comment comment) {
-        this.comments.add(comment);
+        if (!this.comments.contains(comment)) {
+            this.comments.add(comment);
+        }
     }
 
     protected void setSummary(String summary) {
         this.summary = summary;
     }
 
     protected void addTag(String tag) {
-        this.tags.add(tag);
+        if (!this.tags.contains(tag)) {
+            this.tags.add(tag);
+        }
     }
 
     public Analysis getAnalysis() {

src/main/java/analyzer/Tags.java

@@ -1,9 +1,9 @@
 package analyzer;
 
-import java.util.Set;
+import java.util.List;
 
-public record Tags(Set<String> tags) {
+public record Tags(List<String> tags) {
     public Tags {
-        tags = Set.copyOf(tags);
+        tags = List.copyOf(tags);
     }
 }

src/test/java/analyzer/JsonSerializerTest.java

@@ -1,13 +1,12 @@
 package analyzer;
 
-import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Set;
 import java.util.stream.Stream;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -49,11 +48,11 @@ public void serializeComment(Comment comment, String expected) {
     private static Stream<Arguments> analyses() {
         return Stream.of(
                 Arguments.of(
-                        new Analysis(Set.of(new TestComment("key")), null),
+                        new Analysis(List.of(new TestComment("key")), null),
                         """
                                 {"comments":[{"comment":"key"}]}"""),
                 Arguments.of(
-                        new Analysis(Set.of(new TestComment("key")), "Lorum ipsum"),
+                        new Analysis(List.of(new TestComment("key")), "Lorum ipsum"),
                         """
                                 {"summary":"Lorum ipsum","comments":[{"comment":"key"}]}""")
         );
@@ -66,12 +65,20 @@ public void serializeAnalysis(Analysis analysis, String expected) {
         assertThat(actual).isEqualTo(expected);
     }
 
-    @Test
-    public void serializeTags() {
-        var tags = new Tags(Set.of("tag1", "tag2", "tag3"));
-        var actual = JsonSerializer.serialize(tags);
-        assertThat(actual.keySet()).containsExactlyInAnyOrder("tags");
-        assertThat(actual.getJSONArray("tags")).containsExactlyInAnyOrder("tag1", "tag2", "tag3");
+    private static Stream<Arguments> tags() {
+        return Stream.of(
+                Arguments.of(new Tags(List.of()), "{}"),
+                Arguments.of(new Tags(List.of("tag1", "tag2", "tag3")),
+                        """
+                                {"tags":["tag1","tag2","tag3"]}""")
+        );
+    }
+
+    @MethodSource("tags")
+    @ParameterizedTest(name = "{0}")
+    public void serializeTags(Tags tags, String expected) {
+        var actual = JsonSerializer.serialize(tags).toString();
+        assertThat(actual).isEqualTo(expected);
     }
 
     private static class TestComment extends Comment {

tests/hamming/expected_analysis.json

@@ -1,4 +1,4 @@
 {"comments": [
-  {"comment": "java.hamming.should_use_string_is_empty"},
-  {"comment": "java.hamming.calculate_distance_in_constructor"}
+  {"comment": "java.hamming.calculate_distance_in_constructor"},
+  {"comment": "java.hamming.should_use_string_is_empty"}
 ]}