Create FileUtils#delete and write tests for FileUtils

src/main/java/fr/xephi/authme/mail/SendMailSSL.java

@@ -6,6 +6,7 @@ import fr.xephi.authme.settings.Settings;
 import fr.xephi.authme.settings.properties.EmailSettings;
 import fr.xephi.authme.settings.properties.SecuritySettings;
 import fr.xephi.authme.util.BukkitService;
+import fr.xephi.authme.util.FileUtils;
 import fr.xephi.authme.util.StringUtils;
 import org.apache.commons.mail.EmailConstants;
 import org.apache.commons.mail.EmailException;
@@ -91,9 +92,7 @@ public class SendMailSSL {
                 }
 
                 sendEmail(content, email);
-                if (file != null) {
-                    file.delete();
-                }
+                FileUtils.delete(file);
             }
         });
     }

src/main/java/fr/xephi/authme/util/FileUtils.java

@@ -68,7 +68,22 @@ public final class FileUtils {
             if (target.isDirectory()) {
                 purgeDirectory(target);
             }
-            target.delete();
+            delete(target);
+        }
+    }
+
+    /**
+     * Delete the given file or directory and log a message if it was unsuccessful.
+     * Method is null safe and does nothing when null is passed.
+     *
+     * @param file the file to delete
+     */
+    public static void delete(File file) {
+        if (file != null) {
+            boolean result = file.delete();
+            if (!result) {
+                ConsoleLogger.warning("Could not delete file '" + file + "'");
+            }
         }
     }
 }

src/main/java/fr/xephi/authme/util/GeoLiteAPI.java

@@ -64,9 +64,7 @@ public class GeoLiteAPI {
                     return false;
                 }
             } else {
-                if (!dataFile.delete()) {
-                    ConsoleLogger.warning("Failed to delete GeoLiteAPI database");
-                }
+                FileUtils.delete(dataFile);
             }
         }
         // Ok, let's try to download the data file!

src/test/java/fr/xephi/authme/util/FileUtilsTest.java

@@ -0,0 +1,131 @@
+package fr.xephi.authme.util;
+
+import com.google.common.io.Files;
+import fr.xephi.authme.TestHelper;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Test for {@link FileUtils}.
+ */
+public class FileUtilsTest {
+
+    @BeforeClass
+    public static void initLogger() {
+        TestHelper.setupLogger();
+    }
+
+    @Rule
+    public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+    @Test
+    public void shouldNotCopyFile() throws IOException {
+        // given
+        File folder = temporaryFolder.newFolder();
+        File file = new File(folder, "config.yml");
+        // purposely don't copy config.yml to verify that config.yml isn't copied by the method
+        File emailJarFile = TestHelper.getJarFile("/email.html");
+        Files.copy(emailJarFile, file);
+
+        // when
+        boolean result = FileUtils.copyFileFromResource(file, "config.yml");
+
+        // then
+        assertThat(result, equalTo(true));
+        assertThat(file.length(), equalTo(emailJarFile.length()));
+    }
+
+    @Test
+    public void shouldCopyFileFromJar() throws IOException {
+        // given
+        File folder = temporaryFolder.newFolder();
+        File file = new File(folder, "some/folders/config.yml");
+
+        // when
+        boolean result = FileUtils.copyFileFromResource(file, "config.yml");
+
+        // then
+        assertThat(result, equalTo(true));
+        assertThat(file.exists(), equalTo(true));
+        File configJarFile = TestHelper.getJarFile("/config.yml");
+        assertThat(file.length(), equalTo(configJarFile.length()));
+    }
+
+    @Test
+    public void shouldReturnFalseForInvalidJarFile() throws IOException {
+        // given
+        File folder = temporaryFolder.newFolder();
+        File file = new File(folder, "bogus");
+
+        // when
+        boolean result = FileUtils.copyFileFromResource(file, "does-not-exist");
+
+        // then
+        assertThat(result, equalTo(false));
+        assertThat(file.exists(), equalTo(false));
+    }
+
+    @Test
+    public void shouldPurgeDirectory() throws IOException {
+        // given
+        File root = temporaryFolder.newFolder();
+        File file1 = new File(root, "a/b/c/test.html");
+        File file2 = new File(root, "a/b/f/toast.txt");
+        File file3 = new File(root, "a/g/rest.png");
+        File file4 = new File(root, "j/l/roast.tiff");
+        createFiles(file1, file2, file3, file4);
+
+        // when
+        FileUtils.purgeDirectory(new File(root, "a"));
+
+        // then
+        assertThat(file1.exists(), equalTo(false));
+        assertThat(file2.exists(), equalTo(false));
+        assertThat(file3.exists(), equalTo(false));
+        assertThat(file4.exists(), equalTo(true));
+        assertThat(new File(root, "a").exists(), equalTo(true));
+    }
+
+    @Test
+    public void shouldDeleteFile() throws IOException {
+        // given
+        File file = temporaryFolder.newFile();
+        assertThat(file.exists(), equalTo(true));
+
+        // when
+        FileUtils.delete(file);
+
+        // then
+        assertThat(file.exists(), equalTo(false));
+    }
+
+    @Test
+    public void shouldDoNothingForNullFile() {
+        // given
+        File file = null;
+
+        // when
+        FileUtils.delete(file);
+
+        // then
+        // Nothing happens
+    }
+
+    private static void createFiles(File... files) throws IOException {
+        for (File file : files) {
+            boolean result = file.getParentFile().mkdirs() & file.createNewFile();
+            if (!result) {
+                throw new IllegalStateException("Cannot create file '" + file + "'");
+            }
+        }
+    }
+
+}