Merge pull request #4704 from fpacanowski/master

Fix `BlockString.trim_whitespace` to conform to spec.

lib/graphql/language/block_string.rb

@@ -47,10 +47,10 @@ def self.trim_whitespace(str)
         end
 
         # Remove leading & trailing blank lines
-        while lines.size > 0 && lines[0].empty?
+        while lines.size > 0 && contains_only_whitespace?(lines.first)
           lines.shift
         end
-        while lines.size > 0 && lines[-1].empty?
+        while lines.size > 0 && contains_only_whitespace?(lines.last)
           lines.pop
         end
 
@@ -106,6 +106,10 @@ def self.break_line(line, length)
 
         nil
       end
+
+      def self.contains_only_whitespace?(line)
+        line.match?(/^\s*$/)
+      end
     end
   end
 end

spec/graphql/language/block_string_spec.rb

@@ -63,6 +63,18 @@ def trim_whitespace(str)
           # Doesn't crash when the string is only a newline
           "\n",
           ""
+        ],
+        [
+          # Removes long blank lines
+          "  \n                                     \n
+          Hello,
+            World!
+
+          Yours,
+            GraphQL.
+
+          \n                                        \n",
+          "Hello,\n  World!\n\nYours,\n  GraphQL."
         ]
       ]