api: Nag when somebody does something naughty

api/src/main/java/net/kyori/adventure/text/LegacyFormattingDetected.java

@@ -0,0 +1,32 @@
+/*
+ * This file is part of adventure, licensed under the MIT License.
+ *
+ * Copyright (c) 2017-2021 KyoriPowered
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package net.kyori.adventure.text;
+
+import net.kyori.adventure.util.Nag;
+
+final class LegacyFormattingDetected extends Nag {
+  LegacyFormattingDetected(final Component component) {
+    super("Legacy formatting codes have been detected in a component - this is unsupported behaviour. Please refer to the Adventure documentation (https://docs.adventure.kyori.net) for more information. Component: " + component);
+  }
+}

api/src/main/java/net/kyori/adventure/text/TextComponentImpl.java

@@ -28,13 +28,17 @@
 import java.util.Objects;
 import java.util.stream.Stream;
 import net.kyori.adventure.text.format.Style;
+import net.kyori.adventure.util.Nag;
 import net.kyori.examination.ExaminableProperty;
 import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import static java.util.Objects.requireNonNull;
 
 final class TextComponentImpl extends AbstractComponent implements TextComponent {
+  private static final boolean WARN_WHEN_LEGACY_FORMATTING_DETECTED = Boolean.getBoolean(String.join(".", "net", "kyori", "adventure", "text", "warnWhenLegacyFormattingDetected"));
+  private static final char SECTION_CHAR = '§';
+
   static final TextComponent EMPTY = createDirect("");
   static final TextComponent NEWLINE = createDirect("\n");
   static final TextComponent SPACE = createDirect(" ");
@@ -48,6 +52,12 @@ final class TextComponentImpl extends AbstractComponent implements TextComponent
   TextComponentImpl(final @NonNull List<? extends ComponentLike> children, final @NonNull Style style, final @NonNull String content) {
     super(children, style);
     this.content = content;
+
+    if(WARN_WHEN_LEGACY_FORMATTING_DETECTED) {
+      if(content.indexOf(SECTION_CHAR) != -1) {
+        Nag.print(new LegacyFormattingDetected(this));
+      }
+    }
   }
 
   @Override

api/src/main/java/net/kyori/adventure/util/Nag.java

@@ -0,0 +1,53 @@
+/*
+ * This file is part of adventure, licensed under the MIT License.
+ *
+ * Copyright (c) 2017-2021 KyoriPowered
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package net.kyori.adventure.util;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+/**
+ * A nag.
+ *
+ * @since 4.7.0
+ */
+public abstract class Nag extends RuntimeException {
+  /**
+   * Prints a nag.
+   *
+   * @param nag the nag
+   * @since 4.7.0
+   */
+  public static void print(final @NonNull Nag nag) {
+    nag.printStackTrace();
+  }
+
+  /**
+   * Constructs with a message.
+   *
+   * @param message the message
+   * @since 4.7.0
+   */
+  protected Nag(final String message) {
+    super(message);
+  }
+}