From 1ec3f47e7852af6ab7b422839cf37fcaa21a4dca Mon Sep 17 00:00:00 2001
From: Kevin Thomas <kevintab@tutanota.com>
Date: Thu, 18 Jul 2019 12:38:32 +0530
Subject: [PATCH] Fix #7087: Add log for "contains no units" SyntaxError
 (#7157)

* Fixes #2197 and #2195

* fix e2e error (library)

* Use URL as constants

* Constants in all caps

* Fix linting issue

* adds log for #7087

* address review comment

* address review comment

* log earlierInput
---
 .../directives/NumberWithUnitsValidationService.ts  | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/extensions/interactions/NumberWithUnits/directives/NumberWithUnitsValidationService.ts b/extensions/interactions/NumberWithUnits/directives/NumberWithUnitsValidationService.ts
index 0b4c1926ad25..64364f3dacd7 100644
--- a/extensions/interactions/NumberWithUnits/directives/NumberWithUnitsValidationService.ts
+++ b/extensions/interactions/NumberWithUnits/directives/NumberWithUnitsValidationService.ts
@@ -72,8 +72,17 @@ oppia.factory('NumberWithUnitsValidationService', [
           }
           var earlierInputString = earlierInput.toMathjsCompatibleString();
           var laterInputString = laterInput.toMathjsCompatibleString();
-          return math.unit(laterInputString).equals(math.unit(
-            earlierInputString));
+          try {
+            return math.unit(laterInputString).equals(math.unit(
+              earlierInputString));
+          } catch (e) {
+            var additionalInfo = (
+              '\nlaterInput: ' + JSON.stringify(laterInput.toDict()) +
+              '\nearlierInput: ' + JSON.stringify(earlierInput.toDict())
+            );
+            e.message += additionalInfo;
+            throw e;
+          }
         };
 
         var ranges = [];