1 files changed, 9 insertions, 6 deletions
diff --git a/node_modules/istanbul-lib-instrument/dist/visitor.js b/node_modules/istanbul-lib-instrument/dist/visitor.js
index c1308b24c..55a616848 100644
--- a/node_modules/istanbul-lib-instrument/dist/visitor.js
+++ b/node_modules/istanbul-lib-instrument/dist/visitor.js
@@ -8,6 +8,8 @@ var _createClass = function () { function defineProperties(target, props) { for
 
 var _sourceCoverage = require('./source-coverage');
 
+var _constants = require('./constants');
+
 var _crypto = require('crypto');
 
 var _babelTemplate = require('babel-template');
@@ -18,8 +20,6 @@ function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { de
 
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 
-// function to use for creating hashes
-var SHA = 'sha1';
 // istanbul ignore comment pattern
 var COMMENT_RE = /^\s*istanbul\s+ignore\s+(if|else|next)(?=\W|$)/;
 // source map URL pattern
@@ -27,7 +27,7 @@ var SOURCE_MAP_RE = /[#@]\s*sourceMappingURL=(.*)\s*$/m;
 
 // generate a variable name from hashing the supplied file path
 function genVar(filename) {
-    var hash = (0, _crypto.createHash)(SHA);
+    var hash = (0, _crypto.createHash)(_constants.SHA);
     hash.update(filename);
     return 'cov_' + parseInt(hash.digest('hex').substr(0, 12), 16).toString(36);
 }
@@ -486,8 +486,8 @@ var coverageTemplate = (0, _babelTemplate2.default)('\n    var COVERAGE_VAR = (f
  * @param {string} [opts.coverageVariable=__coverage__] the global coverage variable name.
  */
 function programVisitor(types) {
-    var sourceFilePath = arguments.length <= 1 || arguments[1] === undefined ? 'unknown.js' : arguments[1];
-    var opts = arguments.length <= 2 || arguments[2] === undefined ? { coverageVariable: '__coverage__' } : arguments[2];
+    var sourceFilePath = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 'unknown.js';
+    var opts = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : { coverageVariable: '__coverage__' };
 
     var T = types;
     var visitState = new VisitState(types, sourceFilePath);
@@ -498,8 +498,10 @@ function programVisitor(types) {
         exit: function exit(path) {
             visitState.cov.freeze();
             var coverageData = visitState.cov.toJSON();
-            var hash = (0, _crypto.createHash)(SHA).update(JSON.stringify(coverageData)).digest('hex');
+            coverageData[_constants.MAGIC_KEY] = _constants.MAGIC_VALUE;
+            var hash = (0, _crypto.createHash)(_constants.SHA).update(JSON.stringify(coverageData)).digest('hex');
             var coverageNode = T.valueToNode(coverageData);
+            delete coverageData[_constants.MAGIC_KEY];
             var cv = coverageTemplate({
                 GLOBAL_COVERAGE_VAR: T.stringLiteral(opts.coverageVariable),
                 COVERAGE_VAR: T.identifier(visitState.varName),
@@ -507,6 +509,7 @@ function programVisitor(types) {
                 INITIAL: coverageNode,
                 HASH: T.stringLiteral(hash)
             });
+            cv._blockHoist = 3;
             path.node.body.unshift(cv);
             return {
                 fileCoverage: coverageData,