Ignore empty lines in indent filter #681

CHANGES

@@ -29,13 +29,15 @@ Version 2.10
 - Add tests for all comparison operators: ``eq``, ``ne``, ``lt``, ``le``,
   ``gt``, ``ge``. (`#665`_)
 - ``import`` statement cannot end with a trailing comma. (`#617`_, `#618`_)
+- ``indent`` filter will not indent blank lines by default. (`#685`_)
 
 .. _#469: https://github.com/pallets/jinja/pull/469
 .. _#475: https://github.com/pallets/jinja/pull/475
 .. _#478: https://github.com/pallets/jinja/pull/478
 .. _#617: https://github.com/pallets/jinja/pull/617
 .. _#618: https://github.com/pallets/jinja/pull/618
 .. _#665: https://github.com/pallets/jinja/pull/665
+.. _#685: https://github.com/pallets/jinja/pull/685
 
 Version 2.9.6
 -------------

jinja2/filters.py

@@ -11,6 +11,7 @@
 import re
 import math
 import random
+import warnings
 
 from itertools import groupby, chain
 from collections import namedtuple
@@ -525,21 +526,44 @@ def do_urlize(eval_ctx, value, trim_url_limit=None, nofollow=False,
     return rv
 
 
-def do_indent(s, width=4, indentfirst=False):
-    """Return a copy of the passed string, each line indented by
-    4 spaces. The first line is not indented. If you want to
-    change the number of spaces or indent the first line too
-    you can pass additional parameters to the filter:
+def do_indent(
+    s, width=4, first=False, blank=False, indentfirst=None
+):
+    """Return a copy of the string with each line indented by 4 spaces. The
+    first line and blank lines are not indented by default.
 
-    .. sourcecode:: jinja
+    :param width: Number of spaces to indent by.
+    :param first: Don't skip indenting the first line.
+    :param blank: Don't skip indenting empty lines.
+
+    .. versionchanged:: 2.10
+        Blank lines are not indented by default.
 
-        {{ mytext|indent(2, true) }}
-            indent by two spaces and indent the first line too.
+        Rename the ``indentfirst`` argument to ``first``.
     """
+    if indentfirst is not None:
+        warnings.warn(DeprecationWarning(
+            'The "indentfirst" argument is renamed to "first".'
+        ), stacklevel=2)
+        first = indentfirst
+
+    s += u'\n'  # this quirk is necessary for splitlines method
     indention = u' ' * width
-    rv = (u'\n' + indention).join(s.splitlines())
-    if indentfirst:
+
+    if blank:
+        rv = (u'\n' + indention).join(s.splitlines())
+    else:
+        lines = s.splitlines()
+        rv = lines.pop(0)
+
+        if lines:
+            rv += u'\n' + u'\n'.join(
+                indention + line if line else line for line in lines
+            )
+
+    if first:
         rv = indention + rv
+
     return rv
 
 

tests/test_filters.py

@@ -136,11 +136,26 @@ def test_format(self, env):
         assert out == 'a|b'
 
     def test_indent(self, env):
-        tmpl = env.from_string('{{ foo|indent(2) }}|{{ foo|indent(2, true) }}')
-        text = '\n'.join([' '.join(['foo', 'bar'] * 2)] * 2)
-        out = tmpl.render(foo=text)
-        assert out == ('foo bar foo bar\n  foo bar foo bar|  '
-                       'foo bar foo bar\n  foo bar foo bar')
+        text = '\n'.join(['', 'foo bar', ''])
+        t = env.from_string('{{ foo|indent(2, false, false) }}')
+        assert t.render(foo=text) == '\n  foo bar\n'
+        t = env.from_string('{{ foo|indent(2, false, true) }}')
+        assert t.render(foo=text) == '\n  foo bar\n  '
+        t = env.from_string('{{ foo|indent(2, true, false) }}')
+        assert t.render(foo=text) == '  \n  foo bar\n'
+        t = env.from_string('{{ foo|indent(2, true, true) }}')
+        assert t.render(foo=text) == '  \n  foo bar\n  '
+
+        t = env.from_string('{{ "jinja"|indent }}')
+        assert t.render() == 'jinja'
+        t = env.from_string('{{ "jinja"|indent(first=true) }}')
+        assert t.render() == '    jinja'
+        t = env.from_string('{{ "jinja"|indent(blank=true) }}')
+        assert t.render() == 'jinja'
+
+    def test_indentfirst_deprecated(self, env):
+        with pytest.warns(DeprecationWarning):
+            env.from_string('{{ "jinja"|indent(indentfirst=true) }}').render()
 
     def test_int(self, env):
         class IntIsh(object):