Merge pull request #1811 from opal/elia/empty-x-strings

Support empty x-strings
opal · Apr 30, 2018 · 2c95900 · 2c95900
2 parents fcc3f78 + da987be
commit 2c95900
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Showing 2 changed files with 27 additions and 4 deletions.
diff --git a/lib/opal/nodes/x_string.rb b/lib/opal/nodes/x_string.rb
@@ -38,7 +38,7 @@ def compile_child(child)
         when :str
           value = child.loc.expression.source
           push Fragment.new(value, scope, child)
-        when :begin, :gvar, :ivar
+        when :begin, :gvar, :ivar, :nil
           push expr(child)
         else
           raise "Unsupported xstr part: #{child.type}"
@@ -51,6 +51,8 @@ def compile_single_line(children)
         first_child  = children.shift
         single_child = children.empty?
 
+        first_child ||= s(:nil)
+
         if first_child.type == :str
           first_value = first_child.loc.expression.source.strip
           has_embeded_return = first_value =~ /^return\b/
@@ -125,10 +127,10 @@ def unpack_return(children)
       #   }
       def strip_empty_children(children)
         children = children.dup
-        empty_line = ->(child) { child.type == :str && child.loc.expression.source.rstrip.empty? }
+        empty_line = ->(child) { child.nil? || (child.type == :str && child.loc.expression.source.rstrip.empty?) }
 
-        children.shift while empty_line[children.first]
-        children.pop while empty_line[children.last]
+        children.shift while children.any? && empty_line[children.first]
+        children.pop while children.any? && empty_line[children.last]
 
         children
       end

diff --git a/spec/lib/compiler_spec.rb b/spec/lib/compiler_spec.rb
@@ -440,6 +440,27 @@ def self.exist? path
       end
     end
 
+    specify 'when empty' do
+      expect_compiled(%q{
+        %x{
+        }
+      }).to include("return nil\n")
+
+      expect_compiled(%q{
+        %x{}
+      }).to include("return nil\n")
+
+      expect_compiled(%q{
+        `
+
+        `
+      }).to include("return nil\n")
+
+      expect_compiled(%q{
+        ``
+      }).to include("return nil\n")
+    end
+
     def expect_number_of_warnings(code)
       warnings_number = 0
       compiler = Opal::Compiler.new(code)