text-minimessage: Allow tags to be closed in one tag

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/MiniMessageParser.java

@@ -99,6 +99,7 @@ private void processTokens(final @NotNull StringBuilder sb, final @NotNull Strin
           break;
         case OPEN_TAG:
         case CLOSE_TAG:
+        case OPEN_CLOSE_TAG:
           // extract tag name
           if (token.childTokens().isEmpty()) {
             sb.append(richMessage, token.startIndex(), token.endIndex());

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/MiniMessageSerializer.java

@@ -82,6 +82,18 @@ private static void visit(final @NotNull Component component, final Collector em
   }
 
   static final class Collector implements TokenEmitter, ClaimConsumer {
+    enum TagState {
+      TEXT(false),
+      MID(true),
+      MID_SELF_CLOSING(true);
+
+      final boolean isTag;
+
+      TagState(final boolean isTag) {
+        this.isTag = isTag;
+      }
+    }
+
     /**
      * mark tag boundaries within the stack, without needing to mess with typing too much.
      */
@@ -96,7 +108,7 @@ static final class Collector implements TokenEmitter, ClaimConsumer {
     private final StringBuilder consumer;
     private String[] activeTags = new String[4];
     private int tagLevel = 0;
-    private boolean midTag;
+    private TagState tagState = TagState.TEXT;
 
     Collector(final SerializableResolver resolver, final boolean strict, final StringBuilder consumer) {
       this.resolver = resolver;
@@ -128,7 +140,6 @@ void mark() {
     }
 
     void popToMark() {
-      this.completeTag();
       if (this.tagLevel == 0) {
         return;
       }
@@ -139,7 +150,6 @@ void popToMark() {
     }
 
     void popAll() {
-      this.completeTag();
       while (this.tagLevel > 0) {
         final String tag = this.activeTags[--this.tagLevel];
         if (tag != MARK) {
@@ -149,9 +159,9 @@ void popAll() {
     }
 
     void completeTag() {
-      if (this.midTag) {
+      if (this.tagState.isTag) {
         this.consumer.append(TokenParser.TAG_END);
-        this.midTag = false;
+        this.tagState = TagState.TEXT;
       }
     }
 
@@ -162,14 +172,23 @@ public Collector tag(final String token) {
       this.completeTag();
       this.consumer.append(TokenParser.TAG_START);
       this.escapeTagContent(token, QuotingOverride.UNQUOTED);
-      this.midTag = true;
+      this.tagState = TagState.MID;
       this.pushActiveTag(token);
       return this;
     }
 
+    @Override
+    public @NotNull TokenEmitter selfClosingTag(@NotNull final String token) {
+      this.completeTag();
+      this.consumer.append(TokenParser.TAG_START);
+      this.escapeTagContent(token, QuotingOverride.UNQUOTED);
+      this.tagState = TagState.MID_SELF_CLOSING;
+      return null;
+    }
+
     @Override
     public TokenEmitter argument(final String arg) {
-      if (!this.midTag) {
+      if (!this.tagState.isTag) {
         throw new IllegalStateException("Not within a tag!");
       }
       this.consumer.append(TokenParser.SEPARATOR);
@@ -179,7 +198,7 @@ public TokenEmitter argument(final String arg) {
 
     @Override
     public @NotNull TokenEmitter argument(final @NotNull String arg, final @NotNull QuotingOverride quotingPreference) {
-      if (!this.midTag) {
+      if (!this.tagState.isTag) {
         throw new IllegalStateException("Not within a tag!");
       }
       this.consumer.append(TokenParser.SEPARATOR);
@@ -193,15 +212,6 @@ public TokenEmitter argument(final String arg) {
       return this.argument(serialized, QuotingOverride.QUOTED); // always quote tokens
     }
 
-    @Override
-    public Collector selfClosing(final String token) {
-      this.completeTag();
-      this.consumer.append(TokenParser.TAG_START);
-      this.escapeTagContent(token, QuotingOverride.UNQUOTED);
-      this.midTag = true; // TODO: `<tag/>` syntax
-      return this;
-    }
-
     @Override
     public Collector text(final String text) {
       this.completeTag();
@@ -276,17 +286,24 @@ static void appendEscaping(final StringBuilder builder, final String text, final
 
     @Override
     public Collector pop() {
-      this.completeTag();
       this.emitClose(this.popTag(false));
       return this;
     }
 
     private void emitClose(final @NotNull String tag) {
       // currently: we don't keep any arguments, does it ever make sense to?
-      this.consumer.append(TokenParser.TAG_START)
-        .append(TokenParser.CLOSE_TAG);
-      this.escapeTagContent(tag, QuotingOverride.UNQUOTED);
-      this.consumer.append(TokenParser.TAG_END);
+      if (this.tagState.isTag) {
+        if (this.tagState == TagState.MID) { // not _SELF_CLOSING
+          this.consumer.append(TokenParser.CLOSE_TAG);
+        }
+        this.consumer.append(TokenParser.TAG_END);
+        this.tagState = TagState.TEXT;
+      } else {
+        this.consumer.append(TokenParser.TAG_START)
+          .append(TokenParser.CLOSE_TAG);
+        this.escapeTagContent(tag, QuotingOverride.UNQUOTED);
+        this.consumer.append(TokenParser.TAG_END);
+      }
     }
 
     // ClaimCollector

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/parser/TokenParser.java

@@ -215,8 +215,10 @@ public static void parseString(final String message, final MatchedTokenConsumer<
 
               // closing tags start with </
               TokenType thisType = TokenType.OPEN_TAG;
-              if (boundsCheck(message, marker, 1) && message.charAt(marker + 1) == CLOSE_TAG) {
+              if (boundsCheck(message, marker, 1) && message.charAt(marker + 1) == CLOSE_TAG) { // </content>
                 thisType = TokenType.CLOSE_TAG;
+              } else if (boundsCheck(message, marker, 2) && message.charAt(i - 1) == CLOSE_TAG) { // <content/>
+                thisType = TokenType.OPEN_CLOSE_TAG;
               }
               consumer.accept(marker, currentTokenEnd, thisType);
               state = FirstPassState.NORMAL;
@@ -256,13 +258,13 @@ public static void parseString(final String message, final MatchedTokenConsumer<
   private static void parseSecondPass(final String message, final List<Token> tokens) {
     for (final Token token : tokens) {
       final TokenType type = token.type();
-      if (type != TokenType.OPEN_TAG && type != TokenType.CLOSE_TAG) {
+      if (type != TokenType.OPEN_TAG && type != TokenType.OPEN_CLOSE_TAG && type != TokenType.CLOSE_TAG) {
         continue;
       }
 
       // Only look inside the tag <[/] and >
-      final int startIndex = type == TokenType.OPEN_TAG ? token.startIndex() + 1 : token.startIndex() + 2;
-      final int endIndex = token.endIndex() - 1;
+      final int startIndex = type == TokenType.CLOSE_TAG ? token.startIndex() + 2 : token.startIndex() + 1;
+      final int endIndex = type == TokenType.OPEN_CLOSE_TAG ? token.endIndex() - 2 : token.endIndex() - 1;
 
       SecondPassState state = SecondPassState.NORMAL;
       boolean escaped = false;
@@ -365,6 +367,7 @@ private static RootNode buildTree(
           break;
 
         case OPEN_TAG:
+        case OPEN_CLOSE_TAG:
           final TagNode tagNode = new TagNode(node, token, message, tagProvider);
           if (tagNameChecker.test(tagNode.name())) {
             final Tag tag = tagProvider.resolve(tagNode);
@@ -383,8 +386,8 @@ private static RootNode buildTree(
               // This is a recognized tag, goes in the tree
               tagNode.tag(tag);
               node.addChild(tagNode);
-              if (!(tag instanceof Inserting) || ((Inserting) tag).allowsChildren()) {
-                node = tagNode; // TODO: self-terminating tags (i.e. <tag/>) don't set this, so they don't have children
+              if (type != TokenType.OPEN_CLOSE_TAG && (!(tag instanceof Inserting) || ((Inserting) tag).allowsChildren())) {
+                node = tagNode;
               }
             }
           } else {

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/parser/TokenType.java

@@ -31,6 +31,7 @@
 public enum TokenType {
   TEXT,
   OPEN_TAG,
+  OPEN_CLOSE_TAG, // one token that both opens and closes a tag
   CLOSE_TAG,
   TAG_VALUE;
 }

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/serializer/TokenEmitter.java

@@ -42,18 +42,20 @@ public interface TokenEmitter {
   @NotNull TokenEmitter tag(final @NotNull String token); // TODO: some sort of TagFlags, with things like SELF_CLOSING, CLOSE_WITH_ARGUMENTS, etc?
 
   /**
-   * Create a self-contained tag without arguments.
+   * Open a tag with or without arguments that cannot have children.
+   *
+   * <p>These sorts of tags will be closed even without any sort of closing indicator.</p>
    *
    * @param token the token to emit
    * @return this emitter
    * @since 4.10.0
    */
-  @NotNull TokenEmitter selfClosing(final @NotNull String token);
+  @NotNull TokenEmitter selfClosingTag(final @NotNull String token); // TODO: some sort of TagFlags, with things like SELF_CLOSING, CLOSE_WITH_ARGUMENTS, etc?
 
   /**
    * Add arguments to the current tag.
    *
-   * <p>Must be called after {@link #tag(String)} or {@link #selfClosing(String)}, but before any call to {@link #text(String)}.</p>
+   * <p>Must be called after {@link #tag(String)}, but before any call to {@link #text(String)}.</p>
    *
    * @param args args to add
    * @return this emitter
@@ -69,7 +71,7 @@ public interface TokenEmitter {
   /**
    * Add a single argument to the current tag.
    *
-   * <p>Must be called after {@link #tag(String)} or {@link #selfClosing(String)}, but before any call to {@link #text(String)}.</p>
+   * <p>Must be called after {@link #tag(String)}, but before any call to {@link #text(String)}.</p>
    *
    * @param arg argument to add
    * @return this emitter
@@ -80,7 +82,7 @@ public interface TokenEmitter {
   /**
    * Add a single argument to the current tag.
    *
-   * <p>Must be called after {@link #tag(String)} or {@link #selfClosing(String)}, but before any call to {@link #text(String)}.</p>
+   * <p>Must be called after {@link #tag(String)}, but before any call to {@link #text(String)}.</p>
    *
    * @param arg argument to add
    * @param quotingPreference an argument-specific quoting instruction
@@ -92,7 +94,7 @@ public interface TokenEmitter {
   /**
    * Add a single argument to the current tag.
    *
-   * <p>Must be called after {@link #tag(String)} or {@link #selfClosing(String)}, but before any call to {@link #text(String)}.</p>
+   * <p>Must be called after {@link #tag(String)}, but before any call to {@link #text(String)}.</p>
    *
    * @param arg argument to add, serialized as a nested MiniMessage string
    * @return this emitter

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/tag/standard/NewlineTag.java

@@ -52,12 +52,12 @@ private NewlineTag() {
   }
 
   static Tag create(final ArgumentQueue args, final Context ctx) throws ParsingException {
-    return Tag.inserting(Component.newline());
+    return Tag.selfClosingInserting(Component.newline());
   }
 
   static @Nullable Emitable claimComponent(final Component input) {
     if (Component.newline().equals(input)) {
-      return emit -> emit.tag(BR);
+      return emit -> emit.selfClosingTag(BR);
     } else {
       return null;
     }

text-minimessage/src/test/java/net/kyori/adventure/text/minimessage/MiniMessageParserTest.java

@@ -440,4 +440,33 @@ void testTreeOutput() {
 
     assertEquals(expected, tree.toString());
   }
+
+  @Test
+  void testTagsSelfClosable() {
+    final String input = "<red>hello <lang:gameMode.creative/> there";
+
+    final Component parsed = Component.text()
+      .content("hello ")
+      .color(NamedTextColor.RED)
+      .append(
+        Component.translatable("gameMode.creative"),
+        Component.text(" there")
+      )
+      .build();
+
+    this.assertParsedEquals(parsed, input);
+  }
+
+  @Test
+  void testIgnorableSelfClosable() {
+    final String input = "<red/>things";
+
+    final Component parsed = Component.text().append(
+        Component.text("", NamedTextColor.RED),
+        Component.text("things")
+      )
+      .build();
+
+    this.assertParsedEquals(parsed, input);
+  }
 }

text-minimessage/src/test/java/net/kyori/adventure/text/minimessage/tag/standard/KeybindTagTest.java

@@ -36,7 +36,7 @@
 class KeybindTagTest extends AbstractTest {
   @Test
   void testSerializeKeyBind() {
-    final String expected = "Press <key:key.jump></key> to jump!";
+    final String expected = "Press <key:key.jump/> to jump!";
 
     final TextComponent.Builder builder = Component.text()
       .content("Press ")

text-minimessage/src/test/java/net/kyori/adventure/text/minimessage/tag/standard/NewlineTagTest.java

@@ -31,9 +31,16 @@
 import static net.kyori.adventure.text.format.NamedTextColor.GRAY;
 import static net.kyori.adventure.text.format.NamedTextColor.RED;
 import static net.kyori.adventure.text.format.TextColor.color;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class NewlineTagTest extends AbstractTest {
 
+  @Test
+  void testRoundtripNewline() {
+    final String input = "<red>Line</red><br><gray>break!";
+    assertEquals(input, PARSER.serialize(PARSER.deserialize(input)));
+  }
+
   @Test
   void testNewLine() {
     final String input = "<red>Line<br><gray>break!";

text-minimessage/src/test/java/net/kyori/adventure/text/minimessage/tag/standard/TranslatableTagTest.java

@@ -38,7 +38,7 @@
 class TranslatableTagTest extends AbstractTest {
   @Test
   void testSerializeTranslatable() {
-    final String expected = "You should get a <lang:block.minecraft.diamond_block></lang>!";
+    final String expected = "You should get a <lang:block.minecraft.diamond_block/>!";
 
     final TextComponent.Builder builder = Component.text()
       .content("You should get a ")