old_contents: var transform = require("../lib/6to5/transformation/transform");
  var assert    = require("assert");
  var File      = require("../lib/6to5/file");
  
  suite("api", function () {
    test("{ code: false }", function () {
      var result = transform("foo('bar');", { code: false });
      assert.ok(!result.code);
    });
  
    test("addDeclaration unknown", function () {
      var file = new File;
      assert.throws(function () {
        file.addDeclaration("foob");
      }, /unknown declaration foob/);
    });
  });
  
new_contents: var transform = require("../lib/6to5/transformation/transform");
  var assert    = require("assert");
  var File      = require("../lib/6to5/file");
  
  suite("api", function () {
    test("{ code: false }", function () {
      var result = transform("foo('bar');", { code: false });
      assert.ok(!result.code);
    });
  
    test("{ ast: false }", function () {
      var result = transform("foo('bar');", { ast: false });
      assert.ok(!result.ast);
    });
  
    test("addDeclaration unknown", function () {
      var file = new File;
      assert.throws(function () {
        file.addDeclaration("foob");
      }, /unknown declaration foob/);
    });
  });
  
subject: add api opts.ast === false test