refactor!: remove Kotlin from the codebase

.gitignore

@@ -1,3 +1,5 @@
 target
 spotless-index
 .since-index
+*.iml
+.idea

CLAUDE.md

@@ -17,7 +17,6 @@ each Vaadin component in a *tester* that drives it the way a browser would.
 
 - Java 21+, Maven (multi-module)
 - Vaadin 25 / Flow — a `provided` dependency, one fixed version per branch
-- Kotlin for the older mock and internal layer in `shared/src/main/kotlin`
 - JUnit 6 (Jupiter) for the test API and for this repository's own tests
 - An annotation processor (`locator-processor`) that generates the typed
   locator API at build time
@@ -84,7 +83,7 @@ mvn test -pl junit6 -Dtest=BasicGridTesterTest#basicGrid_selectionOnClick
 # Run the tests matching a pattern
 mvn test -pl junit6 -Dtest="*ComboBox*Test"
 
-# Generate the Javadoc/Dokka artifacts the way CI does
+# Generate the Javadoc artifacts the way CI does
 mvn clean install -DskipTests -Djavadocs
 ```
 

CONVENTIONS.md

@@ -112,9 +112,7 @@ Go through the Vaadin extension points rather than around them — fire service
 and session lifecycle events through the `VaadinService` event bus, and forward
 `Instantiator` calls to the real instantiator instead of reimplementing them.
 
-New code in `shared` is written in Java. The Kotlin sources under
-`shared/src/main/kotlin` are the older mock and internal layer and are being
-ported to Java; do not add new Kotlin files there.
+This repository is written in Java; do not add Kotlin sources.
 
 See [`guidelines/architecture.md`](guidelines/architecture.md).
 
@@ -152,6 +150,13 @@ detail.
 Javadoc describes the code today, not what changed. Change history belongs in
 commit messages.
 
+In a tester, spell cross-package `@link` and `@throws` targets out in full:
+`locator-processor` copies the Javadoc into the generated `*Locator`, which has
+no imports. Every module builds clean under doclint, warnings included, so every
+published member needs a description, its `@param`s and its `@return` — a class
+that would otherwise get an undocumented default constructor declares an
+explicit one.
+
 See [`guidelines/documenting.md`](guidelines/documenting.md).
 
 ## Testing

guidelines/architecture.md

@@ -76,7 +76,7 @@ found too — a Dialog's content, a Grid's header, footer and editor components,
 a Card's slots.
 
 `ElementConditions` holds the element-level predicates the query builds on.
-`Locator` (the internal Kotlin one, not the public locator API) and
+`Locator` (the internal one, not the public locator API) and
 `DepthFirstTreeIterator` do the walking; `PrettyPrintTree` renders the tree for
 `TreeOnFailureExtension`.
 

guidelines/documenting.md

@@ -41,6 +41,16 @@ order:
 - **Mark internal API as internal.** "For internal use only. May be renamed or
   removed in a future release." on classes like `BaseBrowserlessTest` is what
   keeps them changeable.
+- **Spell cross-package `@link` and `@throws` targets out in full** in a
+  tester. `locator-processor` copies a tester method's Javadoc into the
+  generated `*Locator`, which has no imports, so `{@link Span}` resolves in the
+  tester and fails there. Write `{@link com.vaadin.flow.component.html.Span
+  Span}`. Same-package names and `{@link #member}` are fine — the processor
+  rewrites the latter to point back at the tester.
+- **Every published member needs a comment.** Every module builds clean under
+  doclint, warnings included, so a missing `@param`, `@return` or description
+  shows up in the `-Djavadocs` build. A class that would otherwise get an
+  undocumented default constructor declares an explicit one.
 
 ## Documenting the mocks
 

guidelines/repository.md

@@ -5,14 +5,11 @@
 - **Java 21+**, **Maven** (multi-module, parent `com.vaadin:vaadin-parent`).
 - **Vaadin 25 / Flow** as a `provided` dependency, one fixed version per
   branch — see [Flow Version](flow-version.md).
-- **Kotlin** for the older mock and internal layer in `shared/src/main/kotlin`.
-  New code is Java; the Kotlin is being ported over time.
 - **JUnit 6 (Jupiter)** for the published test API and for this repository's
-  own tests. A few legacy Kotlin tests still use DynaTest and Karibu DSL.
+  own tests.
 - **ClassGraph** for classpath scanning (routes, testers).
 - **Spotless** with the Eclipse formatter for style; no checkstyle.
-- **Dokka** for Javadoc in the mixed Java/Kotlin modules, `maven-javadoc-plugin`
-  elsewhere.
+- **maven-javadoc-plugin** for Javadoc in every module.
 
 ## Module structure
 
@@ -44,10 +41,10 @@ modules that declare testers.
   `Locator`, `Locators`, `CommercialLocators` and the `Has*Filter` mixins. The
   `*Locator` classes themselves are generated into
   `target/generated-sources/annotations`.
-- **The mocks** live in `com.vaadin.browserless.mocks` (Kotlin):
+- **The mocks** live in `com.vaadin.browserless.mocks` (Java):
   `MockService`, `MockVaadinServlet`, `MockRequest`, `MockResponse`,
   `MockHttpSession`, `MockedUI`.
-- **Internal helpers** live in `com.vaadin.browserless.internal` (Kotlin):
+- **Internal helpers** live in `com.vaadin.browserless.internal` (Java):
   `MockVaadin`, `Routes`, `Locator`, `PrettyPrintTree`, `Shortcuts`.
 - **Tests** live in `junit6/src/test/java`, mirroring the package of the code
   they cover. See [Testing](testing.md).
@@ -73,7 +70,7 @@ Formatting is applied by `mvn spotless:apply` and validated by
 `eclipse/VaadinJavaConventions.xml`, the import order in
 `eclipse/flow.importorder`, the Apache 2 license header in
 `eclipse/apache2-license-header.txt`, no wildcard imports, and a trailing
-newline. Kotlin files get the license header check only.
+newline.
 
 ## Blast radius
 

guidelines/testing.md

@@ -19,8 +19,6 @@ Layout inside `junit6/src/test`:
   `LocatorApiTest`, `SignalsTest`) and the shared test contracts.
 - `java/com/example/…` — views and fixtures that tests navigate to, kept out of
   the framework packages so route scanning stays predictable.
-- `kotlin/` — the remaining DynaTest/Karibu-style tests of the Kotlin internals.
-  Do not add new ones; write new tests as JUnit 6 in Java.
 
 The Spring, Quarkus and CDI integrations have their own test sources, because
 each needs a different container on the classpath. `junit6-cdi-tests` exists

junit6/pom.xml

@@ -22,68 +22,12 @@
         </resources>
 
         <plugins>
-            <!--
-                To compile projects that include Kotlin and Java source code, the Kotlin compiler should run before
-                the Java compiler.
-                That means that kotlin-maven-plugin definition must be placed before maven-compiler-plugin
-            -->
-            <plugin>
-                <groupId>org.jetbrains.kotlin</groupId>
-                <artifactId>kotlin-maven-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <id>compile</id>
-                        <goals>
-                            <goal>compile</goal>
-                        </goals>
-                        <configuration>
-                            <sourceDirs>
-                                <sourceDir>${project.basedir}/src/main/kotlin</sourceDir>
-                                <sourceDir>${project.basedir}/src/main/java</sourceDir>
-                            </sourceDirs>
-                        </configuration>
-                    </execution>
-                    <execution>
-                        <id>test-compile</id>
-                        <goals>
-                            <goal>test-compile</goal>
-                        </goals>
-                        <configuration>
-                            <sourceDirs>
-                                <sourceDir>${project.basedir}/src/test/kotlin</sourceDir>
-                                <sourceDir>${project.basedir}/src/test/java</sourceDir>
-                            </sourceDirs>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <executions>
-                    <!-- Replacing default-compile as it is treated specially by maven -->
-                    <execution>
-                        <id>default-compile</id>
-                        <phase>none</phase>
-                    </execution>
-                    <!-- Replacing default-testCompile as it is treated specially by maven -->
                     <execution>
                         <id>default-testCompile</id>
-                        <phase>none</phase>
-                    </execution>
-                    <execution>
-                        <id>java-compile</id>
-                        <phase>compile</phase>
-                        <goals>
-                            <goal>compile</goal>
-                        </goals>
-                    </execution>
-                    <execution>
-                        <id>java-test-compile</id>
-                        <phase>test-compile</phase>
-                        <goals>
-                            <goal>testCompile</goal>
-                        </goals>
                         <configuration>
                             <!-- End-user-style configuration: run the locator
                                  processor on junit6's own test sources, with
@@ -111,24 +55,6 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
             </plugin>
-            <plugin>
-                <groupId>org.codehaus.mojo</groupId>
-                <artifactId>build-helper-maven-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <id>add-kotlin-sources-for-source-jar</id>
-                        <phase>package</phase>
-                        <goals>
-                            <goal>add-source</goal>
-                        </goals>
-                        <configuration>
-                            <sources>
-                                <source>src/main/kotlin</source>
-                            </sources>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>
@@ -170,18 +96,6 @@
             <scope>provided</scope>
         </dependency>
 
-        <dependency>
-            <groupId>com.github.mvysny.dynatest</groupId>
-            <artifactId>dynatest</artifactId>
-            <version>0.25</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>com.github.mvysny.karibudsl</groupId>
-            <artifactId>karibu-dsl</artifactId>
-            <version>1.0.8</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>com.vaadin</groupId>
             <artifactId>browserless-test-shared</artifactId>
@@ -192,13 +106,6 @@
             <artifactId>junit-jupiter</artifactId>
         </dependency>
 
-        <dependency>
-            <groupId>org.jetbrains.kotlin</groupId>
-            <artifactId>kotlin-stdlib</artifactId>
-            <version>${kotlin.version}</version>
-        </dependency>
-
-
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-simple</artifactId>