feat: Lookup for any Hilla views for auto-detection (#18765)

* feat: Lookup for any Hilla views for auto-detection

* moving method to file utils and add tests

Author: mshabarov

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

@@ -20,7 +20,14 @@
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.FileSystems;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.PathMatcher;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -135,4 +142,44 @@ public static boolean isProbablyTemporaryFile(File file) {
         return file.getName().endsWith("~");
     }
 
+    /**
+     * Get a list of files in a given directory that match a given glob pattern.
+     *
+     * @param baseDir
+     *            a directory to walk in
+     * @param pattern
+     *            glob pattern to filter files, e.g. "*.js".
+     * @return a list of files matching a given pattern
+     * @throws IOException
+     *             if an I/O error is thrown while walking through the tree in
+     *             base directory
+     */
+    public static List<Path> getFilesByPattern(Path baseDir, String pattern)
+            throws IOException {
+        if (baseDir == null || !baseDir.toFile().exists()) {
+            throw new IllegalArgumentException(
+                    "Base directory is empty or doesn't exist: " + baseDir);
+        }
+
+        if (pattern == null || pattern.isBlank()) {
+            pattern = "*";
+        }
+
+        PathMatcher matcher = FileSystems.getDefault()
+                .getPathMatcher("glob:" + pattern);
+
+        List<Path> matchingPaths = new ArrayList<>();
+        Files.walkFileTree(baseDir, new SimpleFileVisitor<Path>() {
+            @Override
+            public FileVisitResult visitFile(Path file,
+                    BasicFileAttributes attrs) {
+                if (matcher.matches(file)) {
+                    matchingPaths.add(file);
+                }
+                return FileVisitResult.CONTINUE;
+            }
+        });
+        return matchingPaths;
+    }
+
 }

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

@@ -15,8 +15,6 @@
  */
 package com.vaadin.flow.server.frontend;
 
-import jakarta.servlet.ServletContext;
-
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
@@ -30,6 +28,7 @@
 import java.nio.file.Path;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -40,6 +39,7 @@
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
+import jakarta.servlet.ServletContext;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.slf4j.Logger;
@@ -60,7 +60,6 @@
 import com.vaadin.flow.server.frontend.scanner.ClassFinder;
 
 import elemental.json.JsonObject;
-
 import static com.vaadin.flow.server.Constants.COMPATIBILITY_RESOURCES_FRONTEND_DEFAULT;
 import static com.vaadin.flow.server.Constants.RESOURCES_FRONTEND_DEFAULT;
 import static com.vaadin.flow.server.Constants.VAADIN_WEBAPP_RESOURCES;
@@ -258,6 +257,12 @@ public class FrontendUtils {
     public static final String FRONTEND_GENERATED_FLOW_IMPORT_PATH = FRONTEND_FOLDER_ALIAS
             + "generated/flow/";
 
+    /**
+     * The default directory in frontend directory, where Hilla views are
+     * located.
+     */
+    public static final String HILLA_VIEWS_PATH = "views";
+
     /**
      * File used to enable npm mode.
      */
@@ -1239,8 +1244,27 @@ public static boolean isReactRouterRequired(File frontendDirectory) {
      */
     public static boolean isHillaViewsUsed(File frontendDirectory) {
         Objects.requireNonNull(frontendDirectory);
-        var files = List.of(FrontendUtils.INDEX_TS, FrontendUtils.ROUTES_TS,
-                FrontendUtils.ROUTES_TSX);
+        File viewsDirectory = new File(frontendDirectory, HILLA_VIEWS_PATH);
+        if (viewsDirectory.exists()) {
+            try {
+                Collection<Path> views = FileIOUtils.getFilesByPattern(
+                        viewsDirectory.toPath(), "**/*.{js,jsx,ts,tsx}");
+                for (Path view : views) {
+                    String viewContent = IOUtils.toString(view.toUri(), UTF_8);
+                    viewContent = StringUtil.removeComments(viewContent);
+                    if (!viewContent.isBlank()) {
+                        return true;
+                    }
+                }
+            } catch (IOException e) {
+                getLogger().error(
+                        "Couldn't scan Hilla views directory for hilla auto-detection",
+                        e);
+            }
+        }
+
+        var files = List.of(FrontendUtils.INDEX_TS, FrontendUtils.INDEX_TSX,
+                FrontendUtils.ROUTES_TS, FrontendUtils.ROUTES_TSX);
         for (String fileName : files) {
             File routesFile = new File(frontendDirectory, fileName);
             if (routesFile.exists()) {

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

@@ -37,7 +37,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.vaadin.flow.di.Lookup;
 import com.vaadin.flow.internal.Pair;
 import com.vaadin.flow.server.ExecutionFailedException;
 import com.vaadin.flow.server.frontend.installer.NodeInstaller;
@@ -177,6 +176,17 @@ public class FrontendUtilsTest {
                   ];
             """;
 
+    private static final String HILLA_VIEW_TSX = """
+                import { VerticalLayout } from "@vaadin/react-components/VerticalLayout.js";
+                export default function AboutView() {
+                    return (
+                        <VerticalLayout theme="padding">
+                            <p>This is a Hilla view</p>
+                        </VerticalLayout>
+                    );
+                }
+            """;
+
     @Test
     public void parseValidVersions() {
         FrontendVersion sixPointO = new FrontendVersion(6, 0);
@@ -604,6 +614,43 @@ public void isHillaViewsUsed_serverSideRoutesMainLayoutTsx_true()
                 FrontendUtils.isHillaViewsUsed(frontend));
     }
 
+    @Test
+    public void isHillaViewsUsed_nonEmptyHillaViewInViews_true()
+            throws IOException {
+        File frontend = null;
+        for (String ext : Arrays.asList(".js", ".jsx", ".ts", ".tsx")) {
+            try {
+                frontend = prepareFrontendForRoutesFile(
+                        FrontendUtils.HILLA_VIEWS_PATH + "/HillaView" + ext,
+                        HILLA_VIEW_TSX);
+                Assert.assertTrue(
+                        "hilla view is present, thus Hilla is expected",
+                        FrontendUtils.isHillaViewsUsed(frontend));
+            } finally {
+                if (frontend != null && frontend.exists()) {
+                    FileUtils.deleteQuietly(frontend);
+                }
+            }
+        }
+    }
+
+    @Test
+    public void isHillaViewsUsed_emptyHillaViewContent_false()
+            throws IOException {
+        File frontend = prepareFrontendForRoutesFile(
+                FrontendUtils.HILLA_VIEWS_PATH + "/HillaView.ts", "//comment");
+        Assert.assertFalse("empty Hilla view, Hilla not expected",
+                FrontendUtils.isHillaViewsUsed(frontend));
+    }
+
+    @Test
+    public void isHillaViewsUsed_noViews_false() throws IOException {
+        File frontend = prepareFrontendForRoutesFile(
+                FrontendUtils.HILLA_VIEWS_PATH + "/foo.css", "some css");
+        Assert.assertFalse("no Hilla views, Hilla not expected",
+                FrontendUtils.isHillaViewsUsed(frontend));
+    }
+
     private File prepareFrontendForRoutesFile(String fileName, String content)
             throws IOException {
         File frontend = tmpDir.newFolder("frontend");