1 files changed, 11 insertions, 2 deletions
diff --git a/node_modules/istanbul-lib-instrument/dist/visitor.js b/node_modules/istanbul-lib-instrument/dist/visitor.js
index beae5d91b..3462f9314 100644
--- a/node_modules/istanbul-lib-instrument/dist/visitor.js
+++ b/node_modules/istanbul-lib-instrument/dist/visitor.js
@@ -101,6 +101,15 @@ var VisitState = function () {
             extractURL(node.trailingComments);
         }
 
+        // for these expressions the statement counter needs to be hoisted, so
+        // function name inference can be preserved
+
+    }, {
+        key: 'counterNeedsHoisting',
+        value: function counterNeedsHoisting(path) {
+            return path.isFunctionExpression() || path.isArrowFunctionExpression() || path.isClassExpression();
+        }
+
         // all the generic stuff that needs to be done on enter for every node
 
     }, {
@@ -174,7 +183,7 @@ var VisitState = function () {
             } : function (x) {
                 return x;
             };
-            return T.unaryExpression('++', wrap(T.memberExpression(T.memberExpression(T.identifier(this.varName), T.identifier(type)), T.numericLiteral(id), true)));
+            return T.updateExpression('++', wrap(T.memberExpression(T.memberExpression(T.identifier(this.varName), T.identifier(type)), T.numericLiteral(id), true)));
         }
     }, {
         key: 'insertCounter',
@@ -184,7 +193,7 @@ var VisitState = function () {
                 path.node.body.unshift(T.expressionStatement(increment));
             } else if (path.isStatement()) {
                 path.insertBefore(T.expressionStatement(increment));
-            } else if ((path.isFunctionExpression() || path.isArrowFunctionExpression()) && T.isVariableDeclarator(path.parentPath)) {
+            } else if (this.counterNeedsHoisting(path) && T.isVariableDeclarator(path.parentPath)) {
                 // make an attempt to hoist the statement counter, so that
                 // function names are maintained.
                 var parent = path.parentPath.parentPath;