fix: Throw exception if Vite and deprecatedV14Bootstrapping are used (#14678) (#14706)

Interrupts application's bootstrapping if Vite + v14 Bootstrapping are detected with the message to fallback to Webpack, sine Vite is not supported yet with this mode.

Fixes #14603

Co-authored-by: Mikhail Shabarov <61410877+mshabarov@users.noreply.github.com>

Author: vaadin-bot

flow-plugins/flow-maven-plugin/src/test/java/com/vaadin/flow/plugin/maven/BuildFrontendMojoTest.java

@@ -44,6 +44,7 @@
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -563,6 +564,7 @@ public void mavenGoal_generateTsFiles_when_enabled() throws Exception {
         Assert.assertTrue(endpointClientApi.exists());
     }
 
+    @Ignore("Vite is not supported when deprecatedV14Bootstrapping is used")
     @Test
     public void mavenGoal_notGenerateOpenApiJson_when_usingDeprecatedV14Bootstrapping()
             throws Exception {

flow-server/src/main/java/com/vaadin/flow/server/frontend/NodeTasks.java

@@ -685,6 +685,17 @@ public File getFlowResourcesFolder() {
         }
     }
 
+    //@formatter:off
+    private static final String V14_BOOTSTRAPPING_VITE_ERROR_MESSAGE =
+            "\n\n************************************************************************************"
+            + "\n*  Vite build tool is not supported when 'useDeprecatedV14Bootstrapping' is used.  *"
+            + "\n*  Please fallback to Webpack build tool via setting the                           *"
+            + "\n*  'com.vaadin.experimental.webpackForFrontendBuild=true' feature flag             *"
+            + "\n*  in [project-root]/src/main/resources/vaadin-featureflags.properties             *"
+            + "\n*  (you may create the file if not exists) and restart the application.            *"
+            + "\n************************************************************************************\n\n";
+    //@formatter:on
+
     // @formatter:off
     // This list keeps the tasks in order so that they are executed
     // without depending on when they are added.
@@ -790,7 +801,12 @@ private NodeTasks(Builder builder) {
             addGenerateTsConfigTask(builder);
         }
 
-        if (!builder.useLegacyV14Bootstrap) {
+        if (builder.useLegacyV14Bootstrap) {
+            if (!featureFlags.isEnabled(FeatureFlags.WEBPACK)) {
+                throw new IllegalStateException(
+                        V14_BOOTSTRAPPING_VITE_ERROR_MESSAGE);
+            }
+        } else {
             addBootstrapTasks(builder);
 
             // use the new Hilla generator if enabled, otherwise use the old

flow-server/src/test/java/com/vaadin/flow/server/frontend/NodeTasksExecutionTest.java

@@ -55,10 +55,10 @@ public void init() throws Exception {
         // Make a builder that doesn't add any commands.
         NodeTasks.Builder builder = new NodeTasks.Builder(
                 Mockito.mock(Lookup.class), null, TARGET);
-        builder.useV14Bootstrap(true);
         builder.withProductionMode(false);
 
         if (DEV_SERVER_WEBPACK.equals(devServerImpl)) {
+            builder.useV14Bootstrap(true);
             builder.setJavaResourceFolder(temporaryFolder.getRoot());
             createFeatureFlagsFile(
                     "com.vaadin.experimental.webpackForFrontendBuild=true");

flow-server/src/test/java/com/vaadin/flow/server/frontend/NodeTasksViteTest.java

@@ -26,6 +26,8 @@
 import java.util.stream.Collectors;
 
 import org.apache.commons.io.FileUtils;
+import org.hamcrest.CoreMatchers;
+import org.hamcrest.MatcherAssert;
 import org.junit.AfterClass;
 import org.junit.Assert;
 import org.junit.Before;
@@ -288,17 +290,32 @@ public void should_GenerateTsConfigAndTsDefinitions_When_Vaadin14BootstrapMode()
                 new DefaultClassFinder(this.getClass().getClassLoader()))
                 .when(mockedLookup).lookup(ClassFinder.class);
         Builder builder = new Builder(mockedLookup, new File(userDir), TARGET)
-                .enablePackagesUpdate(false).useV14Bootstrap(true)
-                .enableImportsUpdate(true).runNpmInstall(false)
-                .withEmbeddableWebComponents(false).useV14Bootstrap(false)
-                .withFlowResourcesFolder(
+                .enablePackagesUpdate(false).enableImportsUpdate(true)
+                .runNpmInstall(false).withEmbeddableWebComponents(false)
+                .useV14Bootstrap(false).withFlowResourcesFolder(
                         new File(userDir, TARGET + "flow-frontend"));
         builder.build().execute();
 
         Assert.assertTrue(new File(userDir, "tsconfig.json").exists());
         Assert.assertTrue(new File(userDir, "types.d.ts").exists());
     }
 
+    @Test
+    public void should_failWithMessage_When_Vaadin14BootstrapModeAndViteAreUsed() {
+        Lookup mockedLookup = mock(Lookup.class);
+        Mockito.doReturn(
+                new DefaultClassFinder(this.getClass().getClassLoader()))
+                .when(mockedLookup).lookup(ClassFinder.class);
+        Builder builder = new Builder(mockedLookup, new File(userDir), TARGET)
+                .useV14Bootstrap(true);
+
+        IllegalStateException exception = Assert.assertThrows(
+                IllegalStateException.class, () -> builder.build().execute());
+        MatcherAssert.assertThat(exception.getMessage(),
+                CoreMatchers.containsString(
+                        "Vite build tool is not supported when 'useDeprecatedV14Bootstrapping' is used"));
+    }
+
     @Test
     public void should_failWithExecutionFailedException_when_customWebpackConfigFileExist()
             throws IOException {

flow-tests/test-root-ui-context/src/main/resources/vaadin-featureflags.properties

@@ -0,0 +1 @@
+com.vaadin.experimental.webpackForFrontendBuild=true