/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you 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 org.apache.jmeter.resources;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.MissingResourceException;
import java.util.PropertyResourceBundle;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;

class ResourceKeyUsageTest {
    // We assume the test starts in "module" (e.g. src/core) directory (which is true for Gradle and IDEs)
    private static final File srcFiledir = new File("src/main/java");

    // Read resource into ResourceBundle and store in List
    private PropertyResourceBundle getRAS(String res) throws Exception {
        InputStream ras = this.getClass().getResourceAsStream(res);
        if (ras == null) {
            return null;
        }
        return new PropertyResourceBundle(ras);
    }

    // Check that calls to getResString use a valid property key name
    @Test
    void checkResourceReferences() throws Exception {
        String resourceName = "/org/apache/jmeter/resources/messages.properties";
        PropertyResourceBundle messagePRB = getRAS(resourceName);
        Assertions.assertNotNull(resourceName, () -> "Resource bundle " + resourceName + " was not found");
        List<String> failures = new ArrayList<>();
        final List<Exception> exceptions = new ArrayList<>();

        PackageTest.findFile(srcFiledir, null, (dir, name) -> {
            final File file = new File(dir, name);
            // Look for calls to JMeterUtils.getResString()
            final Pattern pat = Pattern.compile(".*getResString\\(\"([^\"]+)\"\\).*");
            if (name.endsWith(".java")) {
                try (FileInputStream fis = new FileInputStream(file);
                     InputStreamReader is = new InputStreamReader(fis, StandardCharsets.UTF_8);
                     BufferedReader fileReader = new BufferedReader(is)) {
                    String s;
                    while ((s = fileReader.readLine()) != null) {
                        if (s.matches("\\s*//.*")) { // leading comment
                            continue;
                        }
                        Matcher m = pat.matcher(s);
                        if (m.matches()) {
                            final String key = m.group(1);
                            // Resource keys cannot contain spaces, and are forced to lower case
                            String resKey = key.replace(' ', '_'); // $NON-NLS-1$ // $NON-NLS-2$
                            resKey = resKey.toLowerCase(java.util.Locale.ENGLISH);
                            if (!key.equals(resKey)) {
                                System.out.println(file + ": non-standard message key: '" + key + "'");
                            }
                            try {
                                messagePRB.getString(resKey);
                            } catch (MissingResourceException e) {
                                failures.add(file + ": missing message key: '" + key + "'");
                            }
                        }
                    }
                } catch (IOException e) {
                    exceptions.add(e);
                }
            }
            return file.isDirectory();
        });
        Assertions.assertTrue(exceptions.isEmpty());
        if (failures.isEmpty()) {
            return;
        }
        Assertions.fail(() -> String.join("\n", failures));
    }
}

@@ -918,39 +918,8 @@
 am;%0A
-import java.io.FilenameFilter;%0A
 impo

Remove unused import