fix(typescript-1.5): fix test for "let"

Author: teppeis

test/test.js

@@ -42,11 +42,10 @@ describe('typescript-update', function() {
             }, /^Error: L0: Type 'string' is not assignable to type 'number'./);
         });
 
-        it('throws an error for ES6 "let"', function() {
-            var src = "let x: number = 1;";
-            assert.throws(function() {
-                tss(src);
-            }, /^Error: L0: 'let' declarations are only available when targeting ECMAScript 6 and higher./);
+        it('compiles ES6 "let" to "var"', function() {
+            var src = 'let x: number = 1;';
+            var expected = 'var x = 1;' + eol;
+            assert.equal(tss(src), expected);
         });
 
         it('throws an error for ES6 Promise', function() {
@@ -63,13 +62,13 @@ describe('typescript-update', function() {
             tss = new TypeScriptSimple({target: ts.ScriptTarget.ES6});
         });
 
-        it('compiles ES6 "let"', function() {
+        it('compiles ES6 "let" to "let"', function() {
             var src = "let x: number = 1;";
             var expected = 'let x = 1;' + eol;
             assert.equal(tss.compile(src), expected);
         });
 
-        it('compiles ES6 Promise', function() {
+        it('does not throw for ES6 Promise', function() {
             var src = "var x = new Promise(function (resolve, reject) {" + eol + "});";
             var expected = src + eol;
             assert.equal(tss.compile(src), expected);