Add method "deleteAllFilesAndDirectories"

Provide a method for people who have complex tests and need to clear the
server within the test.

Fixes #5.

Author: stefanbirkner

README.md

@@ -11,7 +11,8 @@ Fake SFTP Server Rule is published under the
 [open an issue](https://github.com/stefanbirkner/fake-sftp-server-rule/issues/new)
 if you want to use it with an older version of Java.
 
-I want to thank my former team SAM at ThoughtWorks for using this library.
+I want to thank my former team SAM at ThoughtWorks for using this library and
+@OArtyomov for his feature request.
 
 
 ## Installation
@@ -22,7 +23,7 @@ Fake SFTP Server Rule is available from
     <dependency>
       <groupId>com.github.stefanbirkner</groupId>
       <artifactId>fake-sftp-server-rule</artifactId>
-      <version>1.2.0</version>
+      <version>1.3.0</version>
     </dependency>
 
 
@@ -142,6 +143,13 @@ verify that it exists or not.
 
 The method returns `true` iff the file exists and it is not a directory.
 
+### Delete all files
+
+If you want to reuse the SFTP server then you can delete all files and
+directories on the SFTP server. (This is rarely necessary because the rule
+itself takes care that every test starts and ends with a clean SFTP server.)
+
+    sftpServer.deleteAllFilesAndDirectories()
 
 ## Contributing
 

pom.xml

@@ -9,7 +9,7 @@
     </parent>
 
     <artifactId>fake-sftp-server-rule</artifactId>
-    <version>1.3.0-SNAPSHOT</version>
+    <version>1.3.0</version>
     <packaging>jar</packaging>
 
     <name>Fake SFTP Server Rule</name>

src/main/java/com/github/stefanbirkner/fakesftpserver/rule/FakeSftpServerRule.java

@@ -12,11 +12,13 @@
 import java.io.InputStream;
 import java.nio.charset.Charset;
 import java.nio.file.*;
+import java.nio.file.attribute.BasicFileAttributes;
 import java.nio.file.attribute.UserPrincipalLookupService;
 import java.nio.file.spi.FileSystemProvider;
 import java.util.Set;
 
 import static com.github.marschall.memoryfilesystem.MemoryFileSystemBuilder.newLinux;
+import static java.nio.file.FileVisitResult.CONTINUE;
 import static java.nio.file.Files.*;
 import static java.util.Collections.singletonList;
 
@@ -133,8 +135,25 @@
  * }
  * </pre>
  * <p>The method returns {@code true} iff the file exists and it is not a directory.
+ *
+ * <h2>Delete all files</h2>
+ * <p>If you want to reuse the SFTP server then you can delete all files and
+ * directories on the SFTP server. (This is rarely necessary because the rule
+ * itself takes care that every test starts and ends with a clean SFTP server.)
+ * <pre>{@link #deleteAllFilesAndDirectories() sftpServer.deleteAllFilesAndDirectories()};</pre>
  */
 public class FakeSftpServerRule implements TestRule {
+    private static final SimpleFileVisitor<Path> DELETE_FILES_AND_DIRECTORIES
+        = new SimpleFileVisitor<Path>() {
+            @Override
+            public FileVisitResult visitFile(
+                Path file,
+                BasicFileAttributes attrs
+            ) throws IOException {
+                delete(file);
+                return CONTINUE;
+            }
+        };
     private int port = 23454;
 
     private FileSystem fileSystem;
@@ -308,6 +327,16 @@ public boolean existsFile(
         return exists(pathAsObject) && !isDirectory(pathAsObject);
     }
 
+    /**
+     * Deletes all files and directories.
+     * @throws IOException if an I/O error is thrown while deleting the files
+     * and directories
+     */
+    public void deleteAllFilesAndDirectories() throws IOException {
+        for (Path directory: fileSystem.getRootDirectories())
+            walkFileTree(directory, DELETE_FILES_AND_DIRECTORIES);
+    }
+
     @Override
     public Statement apply(
         Statement base,

src/test/java/com/github/stefanbirkner/fakesftpserver/rule/FakeSftpServerRuleTest.java

@@ -794,6 +794,98 @@ public void port_can_be_read_after_the_test() {
         }
     }
 
+    public static class cleanup {
+
+        @Test
+        public void deletes_file_in_root_directory() {
+            FakeSftpServerRule sftpServer = new FakeSftpServerRule();
+            executeTestWithRule(
+                () -> {
+                    uploadFile(
+                        sftpServer,
+                        "/dummy_file.bin",
+                        DUMMY_CONTENT
+                    );
+                    sftpServer.deleteAllFilesAndDirectories();
+                    assertFileDoesNotExist(
+                        sftpServer,
+                        "/dummy_file.bin"
+                    );
+                },
+                sftpServer
+            );
+        }
+
+        @Test
+        public void deletes_file_in_directory() {
+            FakeSftpServerRule sftpServer = new FakeSftpServerRule();
+            executeTestWithRule(
+                () -> {
+                    uploadFile(
+                        sftpServer,
+                        "/dummy_directory/dummy_file.bin",
+                        DUMMY_CONTENT
+                    );
+                    sftpServer.deleteAllFilesAndDirectories();
+                    assertFileDoesNotExist(
+                        sftpServer,
+                        "/dummy_directory/dummy_file.bin"
+                    );
+                },
+                sftpServer
+            );
+        }
+
+        @Test
+        public void deletes_directory() {
+            FakeSftpServerRule sftpServer = new FakeSftpServerRule();
+            executeTestWithRule(
+                () -> {
+                    sftpServer.createDirectory("dummy_directory");
+                    sftpServer.deleteAllFilesAndDirectories();
+                    assertDirectoryDoesNotExist(
+                        sftpServer,
+                        "/dummy_directory"
+                    );
+                },
+                sftpServer
+            );
+        }
+
+        @Test
+        public void works_on_an_empty_filesystem() {
+            FakeSftpServerRule sftpServer = new FakeSftpServerRule();
+            executeTestWithRule(
+                sftpServer::deleteAllFilesAndDirectories,
+                sftpServer
+            );
+        }
+
+        private static void assertFileDoesNotExist(
+            FakeSftpServerRule sftpServer,
+            String path
+        ) {
+            boolean exists = sftpServer.existsFile(path);
+            assertThat(exists).isFalse();
+        }
+
+        private static void assertDirectoryDoesNotExist(
+            FakeSftpServerRule sftpServer,
+            String directory
+        ) throws JSchException {
+            Session session = connectToServer(sftpServer);
+            ChannelSftp channel = connectSftpChannel(session);
+            try {
+                assertThatThrownBy(() -> channel.ls(directory))
+                    .isInstanceOf(SftpException.class)
+                    .hasMessage("Internal FileNotFoundException: " + directory);
+            } finally {
+                channel.disconnect();
+                session.disconnect();
+            }
+        }
+    }
+
     private static Session connectToServer(
         FakeSftpServerRule sftpServer
     ) throws JSchException {
@@ -852,7 +944,8 @@ private static void uploadFile(
         ChannelSftp channel = connectSftpChannel(session);
         try {
             Path path = Paths.get(pathAsString);
-            channel.mkdir(path.getParent().toString());
+            if (!path.getParent().equals(path.getRoot()))
+                channel.mkdir(path.getParent().toString());
             channel.put(new ByteArrayInputStream(content), pathAsString);
         } finally {
             channel.disconnect();