Add ERB-like trim mode for tags and outputs

lib/liquid.rb

@@ -24,13 +24,13 @@ module Liquid
   ArgumentSeparator           = ','
   FilterArgumentSeparator     = ':'
   VariableAttributeSeparator  = '.'
-  TagStart                    = /\{\%/
-  TagEnd                      = /\%\}/
+  TagStart                    = /(?:[ \t]*\{\%-|\{\%)/
+  TagEnd                      = /(?:-\%\}[ \t]*\r?\n?|\%\})/
   VariableSignature           = /\(?[\w\-\.\[\]]\)?/
   VariableSegment             = /[\w\-]/
-  VariableStart               = /\{\{/
-  VariableEnd                 = /\}\}/
-  VariableIncompleteEnd       = /\}\}?/
+  VariableStart               = /(?:\r?\n?[ \t]*\{\{-|\{\{)/
+  VariableEnd                 = /(?:-\}\}[ \t]*\r?\n?[ \t]*|\}\})/
+  VariableIncompleteEnd       = /(?:-\}\}?[ \t]*\r?\n?[ \t]*|\}\}?)/
   QuotedString                = /"[^"]*"|'[^']*'/
   QuotedFragment              = /#{QuotedString}|(?:[^\s,\|'"]|#{QuotedString})+/o
   StrictQuotedFragment        = /"[^"]+"|'[^']+'|[^\s|:,]+/

test/liquid/output_test.rb

@@ -113,4 +113,17 @@ def test_link_to
 
     assert_equal expected, Template.parse(text).render(@assigns, :filters => [FunnyFilter])
   end
+
+  def test_trim_mode
+    text = %[
+      abc:
+      {{- best_cars -}}
+      :def
+    ].gsub(/^      /, '')
+    expected = %[
+      abc:bmw:def
+    ].gsub(/^      /, '')
+
+    assert_equal expected, Template.parse(text).render(@assigns)
+  end
 end # OutputTest

test/liquid/trim_mode_test.rb

@@ -0,0 +1,244 @@
+require 'test_helper'
+
+class TrimModeTest < Test::Unit::TestCase
+  include Liquid
+
+  # Make sure the trim isn't applied to standard output
+  def test_standard_output
+    assert_template_result("
+      <div>
+        <p>
+          John
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {{ name }}
+        </p>
+      </div>",
+      'name' => 'John')
+  end
+
+  # Make sure the trim isn't applied to standard tags
+  def test_standard_tags
+    assert_template_result("
+      <div>
+        <p>
+
+          yes
+
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {% if test %}
+          yes
+          {% endif %}
+        </p>
+      </div>",
+      'test' => true)
+    assert_template_result("
+      <div>
+        <p>
+
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {% if test %}
+          no
+          {% endif %}
+        </p>
+      </div>",
+      'test' => false)
+  end
+
+  # Make sure the trim isn't too agressive
+  def test_no_trim_output
+    assert_template_result("<p>John</p>", "<p>{{- name -}}</p>", 'name' => 'John')
+  end
+
+  # Make sure the trim isn't too agressive
+  def test_no_trim_tags
+    assert_template_result("<p>yes</p>", "<p>{%- if test -%}yes{%- endif -%}</p>", 'test' => true)
+    assert_template_result("<p></p>", "<p>{%- if test -%}no{%- endif -%}</p>", 'test' => false)
+  end
+
+  def test_pre_trim_output
+    assert_template_result("
+      <div>
+        <p>John
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {{- name }}
+        </p>
+      </div>",
+      'name' => 'John')
+  end
+
+  def test_pre_trim_tags
+    assert_template_result("
+      <div>
+        <p>
+
+          yes
+
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {%- if test %}
+          yes
+          {%- endif %}
+        </p>
+      </div>",
+      'test' => true)
+    assert_template_result("
+      <div>
+        <p>
+
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {%- if test %}
+          no
+          {%- endif %}
+        </p>
+      </div>",
+      'test' => false)
+  end
+
+  def test_post_trim_output
+    assert_template_result("
+      <div>
+        <p>
+          John</p>
+      </div>", "
+      <div>
+        <p>
+          {{ name -}}
+        </p>
+      </div>",
+      'name' => 'John')
+  end
+
+  def test_post_trim_tags
+    assert_template_result("
+      <div>
+        <p>
+                    yes
+                  </p>
+      </div>", "
+      <div>
+        <p>
+          {% if test -%}
+          yes
+          {% endif -%}
+        </p>
+      </div>",
+      'test' => true)
+    assert_template_result("
+      <div>
+        <p>
+                  </p>
+      </div>", "
+      <div>
+        <p>
+          {% if test -%}
+          no
+          {% endif -%}
+        </p>
+      </div>",
+      'test' => false)
+  end
+
+  def test_trim_output
+    assert_template_result("
+      <div>
+        <p>John</p>
+      </div>", "
+      <div>
+        <p>
+          {{- name -}}
+        </p>
+      </div>",
+      'name' => 'John')
+  end
+
+  def test_trim_tags
+    assert_template_result("
+      <div>
+        <p>
+          yes
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {%- if test -%}
+          yes
+          {%- endif -%}
+        </p>
+      </div>",
+      'test' => true)
+    assert_template_result("
+      <div>
+        <p>
+        </p>
+      </div>", "
+      <div>
+        <p>
+          {%- if test -%}
+          no
+          {%- endif -%}
+        </p>
+      </div>",
+      'test' => false)
+  end
+
+  def test_complex_trim_output
+    assert_template_result("
+      <div>
+        <p>John30</p>
+        <b>
+          John30
+        </b>
+        <i>John
+          30</i>
+      </div>", "
+      <div>
+        <p>
+          {{- name -}}
+          {{- age -}}
+        </p>
+        <b>
+          {{ name -}}
+          {{- age }}
+        </b>
+        <i>
+          {{- name }}
+          {{ age -}}
+        </i>
+      </div>",
+      'name' => 'John', 'age' => 30)
+  end
+
+  def test_complex_trim
+    assert_template_result("
+      <div>
+            <p>John</p>
+      </div>", "
+      <div>
+        {%- if test -%}
+          {%- if another -%}
+            <p>
+              {{- name -}}
+            </p>
+          {%- endif -%}
+        {%- endif -%}
+      </div>",
+      'test' => true, 'another' => true, 'name' => 'John')
+  end
+end # TrimModeTest