Add :expandtabs and :noexpandtabs

babi/buf.py

@@ -59,6 +59,7 @@ class DelModification(NamedTuple):
 class Buf:
     def __init__(self, lines: List[str], tab_size: int = 4) -> None:
         self._lines = lines
+        self.expandtabs = True
         self.tab_size = tab_size
         self.file_y = self.y = self._x = self._x_hint = 0
 
@@ -242,6 +243,13 @@ class Buf:
 
     # rendered lines
 
+    @property
+    def tab_string(self) -> str:
+        if self.expandtabs:
+            return ' ' * self.tab_size
+        else:
+            return '\t'
+
     def rendered_line(self, idx: int, margin: Margin) -> str:
         x = self._cursor_x if idx == self.y else 0
         expanded = self._lines[idx].expandtabs(self.tab_size)

babi/file.py

@@ -524,20 +524,29 @@ class File:
         assert self.selection.start is not None
         sel_y, sel_x = self.selection.start
         (s_y, _), (e_y, _) = self.selection.get()
+        tab_string = self.buf.tab_string
+        tab_size = len(tab_string)
         for l_y in range(s_y, e_y + 1):
             if self.buf[l_y]:
-                self.buf[l_y] = ' ' * self.buf.tab_size + self.buf[l_y]
+                self.buf[l_y] = tab_string + self.buf[l_y]
                 if l_y == self.buf.y:
-                    self.buf.x += self.buf.tab_size
+                    self.buf.x += tab_size
                 if l_y == sel_y and sel_x != 0:
-                    sel_x += self.buf.tab_size
+                    sel_x += tab_size
         self.selection.set(sel_y, sel_x, self.buf.y, self.buf.x)
 
     @edit_action('insert tab', final=False)
     def _tab(self, margin: Margin) -> None:
-        n = self.buf.tab_size - self.buf.x % self.buf.tab_size
+        tab_string = self.buf.tab_string
+        if tab_string == '\t':
+            n = 1
+        else:
+            n = self.buf.tab_size - self.buf.x % self.buf.tab_size
+            tab_string = tab_string[:n]
         line = self.buf[self.buf.y]
-        self.buf[self.buf.y] = line[:self.buf.x] + n * ' ' + line[self.buf.x:]
+        self.buf[self.buf.y] = (
+            line[:self.buf.x] + tab_string + line[self.buf.x:]
+        )
         self.buf.x += n
         self.buf.restore_eof_invariant()
 
@@ -548,9 +557,9 @@ class File:
             self._tab(margin)
 
     def _dedent_line(self, s: str) -> int:
-        bound = min(len(s), self.buf.tab_size)
+        bound = min(len(s), len(self.buf.tab_string))
         i = 0
-        while i < bound and s[i] == ' ':
+        while i < bound and s[i] in (' ', '\t'):
             i += 1
         return i
 

babi/screen.py

@@ -457,6 +457,14 @@ class Screen:
                     for file in self.files:
                         file.buf.set_tab_size(parsed_tab_size)
                     self.status.update('updated!')
+        elif response.startswith(':expandtabs'):
+            for file in self.files:
+                file.buf.expandtabs = True
+            self.status.update('updated!')
+        elif response.startswith(':noexpandtabs'):
+            for file in self.files:
+                file.buf.expandtabs = False
+            self.status.update('updated!')
         elif response == ':comment' or response.startswith(':comment '):
             _, _, comment = response.partition(' ')
             comment = (comment or '#').strip()

tests/features/expandtabs_test.py

@@ -0,0 +1,45 @@
+from testing.runner import and_exit
+from testing.runner import trigger_command_mode
+
+
+def test_set_expandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('a')
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('Left')
+        trigger_command_mode(h)
+        h.press_and_enter(':expandtabs')
+        h.await_text('updated!')
+        h.press('Tab')
+        h.press('^S')
+    assert f.read() == '    a\n'
+
+
+def test_set_noexpandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('a')
+
+    with run(str(f)) as h, and_exit(h):
+        h.press('Left')
+        trigger_command_mode(h)
+        h.press_and_enter(':noexpandtabs')
+        h.await_text('updated!')
+        h.press('Tab')
+        h.press('^S')
+    assert f.read() == '\ta\n'
+
+
+def test_indent_with_expandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('a\nb\nc')
+
+    with run(str(f)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':noexpandtabs')
+        h.await_text('updated!')
+        for _ in range(3):
+            h.press('S-Down')
+        h.press('Tab')
+        h.press('^S')
+    assert f.read() == '\ta\n\tb\n\tc\n'

tests/features/indent_test.py

@@ -1,4 +1,5 @@
 from testing.runner import and_exit
+from testing.runner import trigger_command_mode
 
 
 def test_indent_at_beginning_of_line(run):
@@ -87,6 +88,20 @@ def test_dedent_selection(run, tmpdir):
         h.await_text('\n1\n2\n    3\n')
 
 
+def test_dedent_selection_with_noexpandtabs(run, tmpdir):
+    f = tmpdir.join('f')
+    f.write('1\n\t2\n\t\t3\n')
+    with run(str(f)) as h, and_exit(h):
+        trigger_command_mode(h)
+        h.press_and_enter(':noexpandtabs')
+        h.await_text('updated!')
+        for _ in range(3):
+            h.press('S-Down')
+        h.press('BTab')
+        h.press('^S')
+    assert f.read() == '1\n2\n\t3\n'
+
+
 def test_dedent_beginning_of_line(run, tmpdir):
     f = tmpdir.join('f')
     f.write('    hi\n')