Maintain column width when transforming consts

3 files changed, 10 insertions, 12 deletions

diff --git a/lib/moduleEnv.js b/lib/moduleEnv.js
index cbb76d9..688401e 100644
--- a/lib/moduleEnv.js
+++ b/lib/moduleEnv.js
@@ -111,17 +111,19 @@ function jsExtension(module, filename) {
     var _compile = module._compile;
 
     module._compile = function (content, filename) {
-        const noConstAssignMessage = linter.verify(content, eslintOptions).find(isNoConstAssignMessage);
+        var noConstAssignMessage = linter.verify(content, eslintOptions).find(isNoConstAssignMessage);
+        var line;
+        var column;
 
         if (noConstAssignMessage !== undefined) {
-            const { line, column } = noConstAssignMessage;
-
+            line = noConstAssignMessage.line;
+            column = noConstAssignMessage.column;
             throw new TypeError(`Assignment to constant variable at ${ filename }:${ line }:${ column }`);
         }
 
         _compile.call(
             module,
-            content.replace(matchConst, "$1let$2"), // replace const with let
+            content.replace(matchConst, "$1let  $2"), // replace const with let, while maintaining the column width
             filename
         );
     };
diff --git a/testLib/sharedTestCases.js b/testLib/sharedTestCases.js
index 611a1d6..aa18516 100644
--- a/testLib/sharedTestCases.js
+++ b/testLib/sharedTestCases.js
@@ -260,14 +260,11 @@ module.exports = function () {
     it("should not modify line numbers in stack traces", function () {
         var throwError = rewire("./throwError.js");
 
-        if (process.env.running_under_istanbul === "1") {
-            return;
-        }
         try {
             throwError();
         } catch (err) {
             if (err.stack) {
-                expect(err.stack.split("\n")[1]).to.match(/:7:11/);
+                expect(err.stack.split("\n")[1]).to.match(/:6:26/);
             }
         }
     });
diff --git a/testLib/throwError.js b/testLib/throwError.js
index e85ea36..0993618 100644
--- a/testLib/throwError.js
+++ b/testLib/throwError.js
@@ -1,8 +1,7 @@
 // Using deliberately const here because we know that we're transform const to let
-const test = 1;
+const a = "a";
 
 module.exports = function () {
-    let test = 1;
-
-    throw new Error();
+    // Ensure that column numbers are correct
+    const b = "b"; throw new Error();
 };