handle comments and use strict directives better - fixes #1030

test/fixtures/transformation/es6-destructuring/array-unpack-optimisation/expected.js

@@ -1,6 +1,6 @@
+// opt
 "use strict";
 
-// opt
 var a = 1;
 var b = 2;
 var a = 1;

test/fixtures/transformation/es6-tail-call/ignore-reassigned/expected.js

@@ -1,8 +1,8 @@
-"use strict";
-
 // we need to deopt `test` if it's reassigned as we can't be certain of it's
 // state, ie. it could have been rebound or dereferenced
 
+"use strict";
+
 function test(exit) {
   if (exit) {
     return this.x;

test/fixtures/transformation/strict/leading-comments-with-existing/actual.js

@@ -0,0 +1,4 @@
+// comments
+"use strict";
+
+module.exports = {};

test/fixtures/transformation/strict/leading-comments-with-existing/expected.js

@@ -0,0 +1,4 @@
+// comments
+"use strict";
+
+module.exports = {};

test/fixtures/transformation/strict/leading-comments/actual.js

@@ -0,0 +1,3 @@
+// comments
+
+module.exports = {};

test/fixtures/transformation/strict/leading-comments/expected.js

@@ -0,0 +1,5 @@
+// comments
+
+"use strict";
+
+module.exports = {};