added a spaceless filter

CHANGELOG

@@ -1,5 +1,6 @@
 * 1.38.0 (2019-XX-XX)
 
+ * added a spaceless filter
  * added max value to the "random" function
  * made namespace classes the default classes (PSR-0 ones are aliases now)
  * removed duplicated directory separator in FilesystemLoader

doc/filters/spaceless.rst

@@ -0,0 +1,54 @@
+``spaceless``
+=============
+
+.. versionadded:: 1.38
+
+    The ``spaceless`` filter was added in Twig 1.38.
+
+Use the ``spaceless`` filter to remove whitespace *between HTML tags*, not
+whitespace within HTML tags or whitespace in plain text:
+
+.. code-block:: jinja
+
+    {{
+        "<div>
+            <strong>foo</strong>
+        </div>
+        "|spaceless }}
+
+    {# output will be <div><strong>foo</strong></div> #}
+
+You can combine ``spaceless`` with the ``filter`` tag to apply the
+transformation on large amounts of HTML:
+
+.. code-block:: jinja
+
+    {% filter spaceless %}
+        <div>
+            <strong>foo</strong>
+        </div>
+    {% endfilter %}
+
+    {# output will be <div><strong>foo</strong></div> #}
+
+This tag is not meant to "optimize" the size of the generated HTML content but
+merely to avoid extra whitespace between HTML tags to avoid browser rendering
+quirks under some circumstances.
+
+.. tip::
+
+    If you want to optimize the size of the generated HTML content, gzip
+    compress the output instead.
+
+.. tip::
+
+    If you want to create a tag that actually removes all extra whitespace in
+    an HTML string, be warned that this is not as easy as it seems to be
+    (think of ``textarea`` or ``pre`` tags for instance). Using a third-party
+    library like Tidy is probably a better idea.
+
+.. tip::
+
+    For more information on whitespace control, read the
+    :ref:`dedicated section <templates-whitespace-control>` of the documentation and learn how
+    you can also use the whitespace control modifier on your tags.

doc/tags/spaceless.rst

@@ -1,6 +1,10 @@
 ``spaceless``
 =============
 
+.. tip::
+
+    As of Twig 1.38, use the :doc:`spaceless <../filters/spaceless>` filter instead.
+
 Use the ``spaceless`` tag to remove whitespace *between HTML tags*, not
 whitespace within HTML tags or whitespace in plain text:
 

src/Extension/CoreExtension.php

@@ -184,6 +184,7 @@ class CoreExtension extends AbstractExtension
             new TwigFilter('striptags', 'strip_tags'),
             new TwigFilter('trim', 'twig_trim_filter'),
             new TwigFilter('nl2br', 'nl2br', ['pre_escape' => 'html', 'is_safe' => ['html']]),
+            new TwigFilter('spaceless', 'twig_spaceless', ['is_safe' => ['html']]),
 
             // array helpers
             new TwigFilter('join', 'twig_join_filter'),
@@ -988,6 +989,16 @@ function twig_trim_filter($string, $characterMask = null, $side = 'both')
     }
 }
 
+/**
+ * Removes whitespaces between HTML tags.
+ *
+ * @return string
+ */
+function twig_spaceless($content)
+{
+    return preg_replace('/>\s+</', '><', $content);
+}
+
 /**
  * Escapes a string.
  *

test/Twig/Tests/Fixtures/filters/spaceless.test

@@ -0,0 +1,8 @@
+--TEST--
+"spaceless" filter
+--TEMPLATE--
+{{ "    <div>   <div>   foo   </div>   </div>"|spaceless }}
+--DATA--
+return []
+--EXPECT--
+<div><div>   foo   </div></div>