feat: Add clean-frontend goal to maven plugin (#11968)

Add a goal to clean frontend files handled
by the framework. Most files are removed,
but package.json is only cleaned of framework
managed changes.

Fixes #8885

Author: caalador

flow-plugins/flow-maven-plugin/src/main/java/com/vaadin/flow/plugin/maven/CleanFrontendMojo.java

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2000-2021 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.plugin.maven;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.maven.plugin.MojoFailureException;
+import org.apache.maven.plugins.annotations.LifecyclePhase;
+import org.apache.maven.plugins.annotations.Mojo;
+
+import elemental.json.Json;
+import elemental.json.JsonObject;
+import elemental.json.impl.JsonUtil;
+
+/**
+ * Goal that cleans the frontend files to a clean state.
+ * <p>
+ * Deletes Vaadin dependencies from package.json, the generated frontend folder
+ * and the npm/pnpm-related files and folders:
+ * <ul>
+ * <li>node_modules
+ * <li>pnpm-lock.yaml
+ * <li>package-lock.json
+ * </ul>
+ *
+ * @since 9.0
+ */
+@Mojo(name = "clean-frontend", defaultPhase = LifecyclePhase.CLEAN)
+public class CleanFrontendMojo extends FlowModeAbstractMojo {
+
+    public static final String VAADIN = "vaadin";
+    public static final String DEPENDENCIES = "dependencies";
+    public static final String DEV_DEPENDENCIES = "devDependencies";
+
+    @Override
+    public void execute() throws MojoFailureException {
+        removeNodeModules();
+
+        // Cleanup (p)npm lock file.
+        File lockFile = new File(npmFolder(), "pnpm-lock.yaml");
+        if (!lockFile.exists()) {
+            lockFile = new File(npmFolder(), "package-lock.json");
+        }
+        if (lockFile.exists()) {
+            lockFile.delete();
+        }
+
+        // clean up generated files from frontend
+        if (generatedTsFolder().exists()) {
+            try {
+                FileUtils.deleteDirectory(generatedTsFolder());
+            } catch (IOException exception) {
+                throw new MojoFailureException(
+                        "Failed to remove folder'"
+                                + generatedTsFolder().getAbsolutePath() + "'",
+                        exception);
+            }
+        }
+
+        try {
+            // Clean up package json framework managed versions.
+            File packageJsonFile = new File(npmFolder(), "package.json");
+            if (packageJsonFile.exists()) {
+                JsonObject packageJson = Json.parse(FileUtils.readFileToString(
+                        packageJsonFile, StandardCharsets.UTF_8.name()));
+
+                cleanupPackage(packageJson);
+
+                FileUtils.write(packageJsonFile,
+                        JsonUtil.stringify(packageJson, 2) + "\n",
+                        StandardCharsets.UTF_8.name());
+            }
+        } catch (IOException e) {
+            throw new MojoFailureException(
+                    "Failed to clean 'package.json' file", e);
+        }
+    }
+
+    /**
+     * Try to remove the node_modules folder.
+     * <p>
+     * Log a warning if there was an issue removing the folder.
+     */
+    private void removeNodeModules() {
+        // Remove node_modules folder
+        File nodeModules = new File(npmFolder(), "node_modules");
+        if (nodeModules.exists()) {
+            try {
+                FileUtils.deleteDirectory(nodeModules);
+            } catch (IOException exception) {
+                getLog().debug("Exception removing node_modules", exception);
+                getLog().error(
+                        "Failed to remove '" + nodeModules.getAbsolutePath()
+                                + "'. Please remove it manually.");
+            }
+        }
+    }
+
+    private void cleanupPackage(JsonObject packageJson) {
+        JsonObject dependencies = packageJson.getObject(DEPENDENCIES);
+        JsonObject devDependencies = packageJson.getObject(DEV_DEPENDENCIES);
+
+        if (packageJson.hasKey(VAADIN)) {
+            JsonObject vaadin = packageJson.getObject(VAADIN);
+            JsonObject vaadinDependencies = vaadin.getObject(DEPENDENCIES);
+            JsonObject vaadinDevDependencies = vaadin
+                    .getObject(DEV_DEPENDENCIES);
+
+            // Remove all
+            cleanObject(dependencies, vaadinDependencies);
+            cleanObject(devDependencies, vaadinDevDependencies);
+            packageJson.remove(VAADIN);
+        }
+
+        cleanFrameworkBuildDependenices(dependencies);
+        cleanFrameworkBuildDependenices(devDependencies);
+
+        // Remove the hash to get a npm install executed
+        packageJson.remove("hash");
+
+    }
+
+    private void cleanObject(JsonObject target, JsonObject reference) {
+        if (target == null) {
+            return;
+        }
+        Set<String> removeKeys = new HashSet<>();
+
+        for (String key : target.keys()) {
+            if (reference.hasKey(key)
+                    && target.getString(key).equals(reference.getString(key))) {
+                removeKeys.add(key);
+            }
+        }
+
+        for (String key : removeKeys) {
+            target.remove(key);
+        }
+    }
+
+    /**
+     * Clean any dependencies that target the build folder in the given json
+     * object.
+     * <p>
+     * With default settings it would mean all starting with {@code ./target}.
+     *
+     * @param dependencyObject
+     *            json object to clean
+     */
+    private void cleanFrameworkBuildDependenices(JsonObject dependencyObject) {
+        if (dependencyObject == null) {
+            return;
+        }
+        String buildTargetFolder = "./" + buildFolder();
+
+        Set<String> removeKeys = new HashSet<>();
+        for (String key : dependencyObject.keys()) {
+            if (dependencyObject.getString(key).startsWith(buildTargetFolder)) {
+                removeKeys.add(key);
+            }
+        }
+
+        for (String key : removeKeys) {
+            dependencyObject.remove(key);
+        }
+    }
+
+}

flow-plugins/flow-maven-plugin/src/main/java/com/vaadin/flow/plugin/maven/FrontendDanceMojo.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2000-2021 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.plugin.maven;
+
+import org.apache.maven.plugins.annotations.LifecyclePhase;
+import org.apache.maven.plugins.annotations.Mojo;
+
+/**
+ * This is the hidden `vaadin:dance` to clean up the frontend files.
+ *
+ * @since
+ */
+@Mojo(name = "dance", defaultPhase = LifecyclePhase.CLEAN)
+public class FrontendDanceMojo extends CleanFrontendMojo {
+}