api-builder: trim blank lines from the end of a text block too

Author: petebacondarwin

tools/api-builder/angular.io-package/rendering/trimBlankLines.js

@@ -6,6 +6,9 @@ module.exports = function() {
       while(lines.length && (lines[0].trim() === '')) {
         lines.shift();
       }
+      while(lines.length && (lines[lines.length-1].trim() === '')) {
+        lines.pop();
+      }
       return lines.join('\n');
     }
   };

tools/api-builder/angular.io-package/rendering/trimBlankLines.spec.js

@@ -11,8 +11,8 @@ describe('trimBlankLines filter', function() {
     expect(filter.name).toEqual('trimBlankLines');
   });
 
-  it('should remove all empty lines from the start of the string', function() {
-    expect(filter.process('\n\n\nsome text\n\nmore text\n\n'))
-        .toEqual('some text\n\nmore text\n\n');
+  it('should remove empty lines from the start and end of the string', function() {
+    expect(filter.process('\n  \n\nsome text\n  \nmore text\n  \n'))
+        .toEqual('some text\n  \nmore text');
   });
 });