diff --git a/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py b/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py
index bb85dd1c..8b36a5dc 100644
--- a/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py
+++ b/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py
@@ -11,7 +11,7 @@ from zulip_bots.bots.dropbox_share.test_util import (
     MockHttpResponse
 )
 
-def get_files_list(*args, **kwargs):
+def get_root_files_list(*args, **kwargs):
     return MockListFolderResult(
         entries = [
             MockFileMetadata('foo', '/foo'),
@@ -20,6 +20,21 @@ def get_files_list(*args, **kwargs):
         has_more = False
     )
 
+def get_folder_files_list(*args, **kwargs):
+    return MockListFolderResult(
+        entries = [
+            MockFileMetadata('moo', '/foo/moo'),
+            MockFileMetadata('noo', '/foo/noo'),
+        ],
+        has_more = False
+    )
+
+def get_empty_files_list(*args, **kwargs):
+    return MockListFolderResult(
+        entries = [],
+        has_more = False
+    )
+
 def create_file(*args, **kwargs):
     return MockFileMetadata('foo', '/foo')
 
@@ -36,6 +51,9 @@ def search_files(*args, **kwargs):
         )
     ])
 
+def get_empty_search_result(*args, **kwargs):
+    return MockSearchResult([])
+
 def get_shared_link(*args, **kwargs):
     return MockPathLinkMetadata('http://www.foo.com/boo')
 
@@ -64,10 +82,31 @@ class TestDropboxBot(BotTestCase):
             self.verify_reply('', get_help())
             self.verify_reply('help', get_help())
 
-    def test_dbx_ls(self):
+    def test_dbx_ls_root(self):
         bot_response = " - [foo](https://www.dropbox.com/home/foo)\n"\
                        " - [boo](https://www.dropbox.com/home/boo)"
-        with patch('dropbox.dropbox.Dropbox.files_list_folder', side_effect=get_files_list), \
+        with patch('dropbox.dropbox.Dropbox.files_list_folder', side_effect=get_root_files_list), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply("ls", bot_response)
+
+    def test_dbx_ls_folder(self):
+        bot_response = " - [moo](https://www.dropbox.com/home/foo/moo)\n"\
+                       " - [noo](https://www.dropbox.com/home/foo/noo)"
+        with patch('dropbox.dropbox.Dropbox.files_list_folder', side_effect=get_folder_files_list), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply("ls foo", bot_response)
+
+    def test_dbx_ls_empty(self):
+        bot_response = '`No files available`'
+        with patch('dropbox.dropbox.Dropbox.files_list_folder', side_effect=get_empty_files_list), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply("ls", bot_response)
+
+    def test_dbx_ls_error(self):
+        bot_response = "Please provide a correct folder path\n"\
+                       "Usage: `ls <foldername>` to list folders in directory\n"\
+                       "or simply `ls` for listing folders in the root directory"
+        with patch('dropbox.dropbox.Dropbox.files_list_folder', side_effect=Exception()), \
                 self.mock_config_info(self.config_info):
             self.verify_reply("ls", bot_response)
 
@@ -77,24 +116,52 @@ class TestDropboxBot(BotTestCase):
                 self.mock_config_info(self.config_info):
             self.verify_reply('mkdir foo', bot_response)
 
+    def test_dbx_mkdir_error(self):
+        bot_response = "Please provide a correct folder path and name.\n"\
+                       "Usage: `mkdir <foldername>` to create a folder."
+        with patch('dropbox.dropbox.Dropbox.files_create_folder', side_effect=Exception()), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply('mkdir foo/bar', bot_response)
+
     def test_dbx_rm(self):
         bot_response = "DELETED File/Folder : [foo](https://www.dropbox.com/home/foo)"
         with patch('dropbox.dropbox.Dropbox.files_delete', side_effect=create_file), \
                 self.mock_config_info(self.config_info):
             self.verify_reply('rm foo', bot_response)
 
+    def test_dbx_rm_error(self):
+        bot_response = "Please provide a correct folder path and name.\n"\
+                       "Usage: `rm <foldername>` to delete a folder in root directory."
+        with patch('dropbox.dropbox.Dropbox.files_delete', side_effect=Exception()), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply('rm foo', bot_response)
+
     def test_dbx_write(self):
         bot_response = "Written to file: [foo](https://www.dropbox.com/home/foo)"
         with patch('dropbox.dropbox.Dropbox.files_upload', side_effect=create_file), \
                 self.mock_config_info(self.config_info):
             self.verify_reply('write foo boo', bot_response)
 
+    def test_dbx_write_error(self):
+        bot_response = "Incorrect file path or file already exists.\n"\
+                       "Usage: `write <filename> CONTENT`"
+        with patch('dropbox.dropbox.Dropbox.files_upload', side_effect=Exception()), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply('write foo boo', bot_response)
+
     def test_dbx_read(self):
         bot_response = "**foo** :\nboo"
         with patch('dropbox.dropbox.Dropbox.files_download', side_effect=download_file), \
                 self.mock_config_info(self.config_info):
             self.verify_reply('read foo', bot_response)
 
+    def test_dbx_read_error(self):
+        bot_response = "Please provide a correct file path\n"\
+                       "Usage: `read <filename>` to read content of a file"
+        with patch('dropbox.dropbox.Dropbox.files_download', side_effect=Exception()), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply('read foo', bot_response)
+
     def test_dbx_search(self):
         bot_response = " - [foo](https://www.dropbox.com/home/foo)\n"\
                        " - [fooboo](https://www.dropbox.com/home/fooboo)"
@@ -102,12 +169,59 @@ class TestDropboxBot(BotTestCase):
                 self.mock_config_info(self.config_info):
             self.verify_reply('search foo', bot_response)
 
+    def test_dbx_search_empty(self):
+        bot_response = "No files/folders found matching your query.\n"\
+                       "For file name searching, the last token is used for prefix matching"\
+                       " (i.e. “bat c” matches “bat cave” but not “batman car”)."
+        with patch('dropbox.dropbox.Dropbox.files_search', side_effect=get_empty_search_result), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply('search boo --fd foo', bot_response)
+
+    def test_dbx_search_error(self):
+        bot_response = "Usage: `search <foldername> query --mr 10 --fd <folderName>`\n"\
+                       "Note:`--mr <int>` is optional and is used to specify maximun results.\n"\
+                       "     `--fd <folderName>` to search in specific folder."
+        with patch('dropbox.dropbox.Dropbox.files_search', side_effect=Exception()), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply('search foo', bot_response)
+
     def test_dbx_share(self):
         bot_response = 'http://www.foo.com/boo'
         with patch('dropbox.dropbox.Dropbox.sharing_create_shared_link', side_effect=get_shared_link), \
                 self.mock_config_info(self.config_info):
             self.verify_reply('share boo', bot_response)
 
+    def test_dbx_share_error(self):
+        bot_response = "Please provide a correct file name.\n"\
+                       "Usage: `share <filename>`"
+        with patch('dropbox.dropbox.Dropbox.sharing_create_shared_link', side_effect=Exception()), \
+                self.mock_config_info(self.config_info):
+            self.verify_reply('share boo', bot_response)
+
+    def test_dbx_help(self):
+        bot_response = 'syntax: ls <optional_path>'
+        with self.mock_config_info(self.config_info):
+            self.verify_reply('help ls', bot_response)
+
+    def test_dbx_usage(self):
+        bot_response = '''
+    Usage:
+    ```
+    @dropbox ls - Shows files/folders in the root folder.
+    @dropbox mkdir foo - Make folder named foo.
+    @dropbox ls foo/boo - Shows the files/folders in foo/boo folder.
+    @dropbox write test hello world - Write "hello world" to the file 'test'.
+    @dropbox rm test - Remove the file/folder test.
+    @dropbox read foo - Read the contents of file/folder foo.
+    @dropbox share foo - Get shareable link for the file/folder foo.
+    @dropbox search boo - Search for boo in root folder and get at max 20 results.
+    @dropbox search boo --mr 10 - Search for boo and get at max 10 results.
+    @dropbox search boo --fd foo - Search for boo in folder foo.
+    ```
+    '''
+        with self.mock_config_info(self.config_info):
+            self.verify_reply('usage', bot_response)
+
     def test_invalid_commands(self):
         ls_error_response = "ERROR: syntax: ls <optional_path>"
         mkdir_error_response = "ERROR: syntax: mkdir <path>"
@@ -115,6 +229,7 @@ class TestDropboxBot(BotTestCase):
         write_error_response = "ERROR: syntax: write <path> <some_text>"
         search_error_response = "ERROR: syntax: search <path> <some_text> <max_results>"
         share_error_response = "ERROR: syntax: share <path>"
+        usage_error_response = "ERROR: syntax: usage"
 
         with self.mock_config_info(self.config_info):
             # ls
@@ -127,3 +242,24 @@ class TestDropboxBot(BotTestCase):
             self.verify_reply("write foo", write_error_response)
             # share
             self.verify_reply("share foo boo", share_error_response)
+            # usage
+            self.verify_reply("usage foo", usage_error_response)
+
+    def test_unkown_command(self):
+        bot_response = '''ERROR: unrecognized command
+
+    Example commands:
+
+    ```
+    @mention-bot usage: see usage examples
+    @mention-bot mkdir: create a folder
+    @mention-bot ls: list a folder
+    @mention-bot write: write text
+    @mention-bot rm: remove a file or folder
+    @mention-bot read: read a file
+    @mention-bot search: search a file/folder
+    @mention-bot share: get a shareable link for the file/folder
+    ```
+    '''
+        with self.mock_config_info(self.config_info):
+            self.verify_reply('unknown command', bot_response)