fixed de-indentation of tabs (aka 4 spaces)

CHANGES.txt

@@ -5,6 +5,9 @@ Changes for crash
 Unreleased
 ==========
 
+ - Fixed an issue where BACKSPACE would delete more characters before the
+   cursor than expected.
+
  - Added support for pasting and executing multiple statements at once.
 
  - Added back support for multiline table headers

src/crate/crash/keybinding.py

@@ -0,0 +1,61 @@
+# vim: set fileencodings=utf-8
+# -*- coding: utf-8; -*-
+#
+# Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
+# license agreements.  See the NOTICE file distributed with this work for
+# additional information regarding copyright ownership.  Crate 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.
+#
+# However, if you have executed another commercial license agreement
+# with Crate these terms will supersede the license and you may use the
+# software solely pursuant to the terms of the relevant commercial agreement.
+
+
+import re
+from prompt_toolkit.keys import Keys
+from prompt_toolkit.filters import Condition
+
+TAB_WIDTH = 4
+WHITESPACE_RE = re.compile(r'\s+$')
+
+
+def doc_condition(fn):
+    return lambda cli: fn(cli.current_buffer.document)
+
+
+def _is_start_of_multiline(doc):
+    return doc.text and not doc.get_word_before_cursor()
+
+
+def _line_ends_with_tab(doc):
+    trailing_ws = WHITESPACE_RE.findall(doc.current_line_before_cursor)
+    return (
+        not doc.get_word_before_cursor() and
+        trailing_ws and
+        len(trailing_ws[0]) % TAB_WIDTH == 0
+    )
+
+
+def bind_keys(registry):
+
+    @registry.add_binding(Keys.Tab,
+                          filter=Condition(
+                              doc_condition(_is_start_of_multiline)))
+    def on_tab(event):
+        event.cli.current_buffer.insert_text(' ' * TAB_WIDTH)
+
+    registry.add_binding(Keys.Backspace,
+                          filter=Condition(
+                              doc_condition(_line_ends_with_tab)))
+    def on_backspace(event):
+        event.cli.current_buffer.delete_before_cursor(TAB_WIDTH)

src/crate/crash/repl.py

@@ -47,12 +47,12 @@
     ConditionalProcessor
 )
 from prompt_toolkit.key_binding.manager import KeyBindingManager
-from prompt_toolkit.keys import Keys
 from prompt_toolkit.shortcuts import (create_output,
                                       create_eventloop)
 
 from .commands import Command
 from .layout import create_layout
+from .keybinding import bind_keys
 
 MAX_HISTORY_LENGTH = 10000
 
@@ -274,32 +274,6 @@ def create_buffer(cmd, history_file):
     buffer.complete_while_typing = lambda cli=None: cmd.should_autocomplete()
     return buffer
 
-
-def _bind_keys(registry):
-
-    def _is_start_of_multiline(cli):
-        doc = cli.current_buffer.document
-        word = doc.get_word_before_cursor()
-        return doc.text and not word
-
-    @registry.add_binding(Keys.Tab, filter=Condition(_is_start_of_multiline))
-    def _(event):
-        event.cli.current_buffer.insert_text('    ')
-
-    def _bs_should_deindent(cli):
-        doc = cli.current_buffer.document
-        start_of_line_pos = doc.get_start_of_line_position()
-        return (
-            not doc.get_word_before_cursor() and
-            start_of_line_pos != 0 and
-            start_of_line_pos % 4 == 0
-        )
-
-    @registry.add_binding(Keys.Backspace, filter=Condition(_bs_should_deindent))
-    def _(event):
-        event.cli.current_buffer.delete_before_cursor(4)
-
-
 def _get_toolbar_tokens(is_conn_available, username, active_servers):
         tokens = []
         if is_conn_available():
@@ -327,7 +301,7 @@ def session_toolbar(cli):
         enable_system_bindings=True,
         enable_open_in_editor=True
     )
-    _bind_keys(key_binding_manager.registry)
+    bind_keys(key_binding_manager.registry)
     layout = create_layout(
         message=u'cr> ',
         multiline=True,

src/crate/crash/test_keybinding.py

@@ -0,0 +1,46 @@
+# Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
+# license agreements.  See the NOTICE file distributed with this work for
+# additional information regarding copyright ownership.  Crate 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.
+#
+# However, if you have executed another commercial license agreement
+# with Crate these terms will supersede the license and you may use the
+# software solely pursuant to the terms of the relevant commercial agreement.
+
+from unittest import TestCase
+from prompt_toolkit.document import Document
+from .keybinding import _is_start_of_multiline, _line_ends_with_tab
+
+
+doc = lambda t: Document(t, len(t))
+is_start_of_multiline = lambda t: _is_start_of_multiline(doc(t))
+line_ends_with_tab = lambda t: _line_ends_with_tab(doc(t))
+
+
+class TabIndentTest(TestCase):
+
+    def test_indent(self):
+        self.assertFalse(is_start_of_multiline(u''))
+        self.assertFalse(is_start_of_multiline(u'SELECT'))
+        self.assertFalse(is_start_of_multiline(u'SELECT\n*'))
+        self.assertTrue(is_start_of_multiline(u'SELECT\n'))
+        self.assertTrue(is_start_of_multiline(u'SELECT\n '))
+        self.assertTrue(is_start_of_multiline(u'\n'))
+
+    def test_deindent(self):
+        self.assertFalse(line_ends_with_tab(u''))
+        self.assertFalse(line_ends_with_tab(u'SELECT'))
+        self.assertFalse(line_ends_with_tab(u'SELECT  '))
+        self.assertFalse(line_ends_with_tab(u'SELECT  \n'))
+        self.assertTrue(line_ends_with_tab(u'SELECT    '))
+        self.assertTrue(line_ends_with_tab(u'SELECT\n    '))

src/crate/crash/tests.py

@@ -37,6 +37,7 @@
 from .test_sysinfo import SysInfoTest
 from .test_repl import SQLCompleterTest, AutoCapitalizeTest, CrashBufferTest, ToolbarTest
 from .test_config import ConfigurationTest
+from .test_keybinding import TabIndentTest
 
 
 class CrateTestCmd(CrateCmd):
@@ -124,5 +125,6 @@ def test_suite():
     suite.addTest(unittest.makeSuite(CrashBufferTest))
     suite.addTest(unittest.makeSuite(ConfigurationTest))
     suite.addTest(unittest.makeSuite(TestGetInformationSchemaQuery))
+    suite.addTest(unittest.makeSuite(TabIndentTest))
 
     return suite