Merge pull request #166 from ankitjavalkar/error-refactor-for-mod

Prettify Error rendering during code questions and grading page

22 files changed, 229 insertions, 214 deletions

diff --git a/yaksh/bash_code_evaluator.py b/yaksh/bash_code_evaluator.py
index 1e6fc9c..975af82 100644
--- a/yaksh/bash_code_evaluator.py
+++ b/yaksh/bash_code_evaluator.py
@@ -104,7 +104,7 @@ class BashCodeEvaluator(BaseEvaluator):
             proc, stdnt_stdout, stdnt_stderr = ret
             if inst_stdout == stdnt_stdout:
                 mark_fraction = float(self.weight) if self.partial_grading else 0.0
-                return True, "Correct answer", mark_fraction
+                return True, None, mark_fraction
             else:
                 err = "Error: expected %s, got %s" % (inst_stderr,
                     stdnt_stderr
@@ -147,7 +147,7 @@ class BashCodeEvaluator(BaseEvaluator):
                     valid_answer = inst_stdout == stdnt_stdout
             if valid_answer and (num_lines == loop_count):
                 mark_fraction = float(self.weight) if self.partial_grading else 0.0
-                return True, "Correct answer", mark_fraction
+                return True, None, mark_fraction
             else:
                 err = ("Error:expected"
                     " {0}, got {1}").format(inst_stdout+inst_stderr,
diff --git a/yaksh/c_cpp_files/main2.c b/yaksh/c_cpp_files/main2.c
index ccd1768..a62195f 100755
--- a/yaksh/c_cpp_files/main2.c
+++ b/yaksh/c_cpp_files/main2.c
@@ -13,7 +13,7 @@ void check(T expect,T result)
     else 
     {
 	printf("\nIncorrect:\n Expected %d got %d \n",expect,result);
-	exit (0);
+	exit (1);
    }
 }
 
diff --git a/yaksh/cpp_code_evaluator.py b/yaksh/cpp_code_evaluator.py
index f0c2029..91ba703 100644
--- a/yaksh/cpp_code_evaluator.py
+++ b/yaksh/cpp_code_evaluator.py
@@ -15,7 +15,7 @@ class CppCodeEvaluator(BaseEvaluator):
     """Tests the C code obtained from Code Server"""
     def __init__(self, metadata, test_case_data):
         self.files = []
-        self.submit_code_path = self.create_submit_code_file('submit.c')
+        self.submit_code_path = ''
         self.compiled_user_answer = None
         self.compiled_test_code = None
         self.user_output_path = ""
@@ -62,6 +62,7 @@ class CppCodeEvaluator(BaseEvaluator):
             ref_code_path = self.test_case
             clean_ref_code_path, clean_test_case_path = \
                 self._set_test_code_file_path(ref_code_path)
+            self.submit_code_path = self.create_submit_code_file('submit.c')
             if self.file_paths:
                 self.files = copy_files(self.file_paths)
             if not isfile(clean_ref_code_path):
@@ -133,7 +134,7 @@ class CppCodeEvaluator(BaseEvaluator):
                 )
                 proc, stdout, stderr = ret
                 if proc.returncode == 0:
-                    success, err = True, "Correct answer"
+                    success, err = True, None
                     mark_fraction = float(self.weight) if self.partial_grading else 0.0
                 else:
                     err = "{0} \n {1}".format(stdout, stderr)
diff --git a/yaksh/evaluator_tests/test_bash_evaluation.py b/yaksh/evaluator_tests/test_bash_evaluation.py
index 06a56e4..abadf26 100644
--- a/yaksh/evaluator_tests/test_bash_evaluation.py
+++ b/yaksh/evaluator_tests/test_bash_evaluation.py
@@ -6,11 +6,12 @@ import tempfile
 from yaksh.grader import Grader
 from yaksh.bash_code_evaluator import BashCodeEvaluator
 from yaksh.bash_stdio_evaluator import BashStdIOEvaluator
+from yaksh.evaluator_tests.test_python_evaluation import EvaluatorBaseTest
 from yaksh.settings import SERVER_TIMEOUT
 from textwrap import dedent
 
 
-class BashAssertionEvaluationTestCases(unittest.TestCase):
+class BashAssertionEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         with open('/tmp/test.txt', 'wb') as f:
             f.write('2'.encode('ascii'))
@@ -48,7 +49,6 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertTrue(result.get('success'))
-        self.assertEqual(result.get('error'), "Correct answer\n")
 
     def test_error(self):
         user_answer = ("#!/bin/bash\n[[ $# -eq 2 ]] "
@@ -67,7 +67,7 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertTrue("Error" in result.get("error"))
+        self.assert_correct_output("Error", result.get("error"))
 
     def test_infinite_loop(self):
         user_answer = ("#!/bin/bash\nwhile [ 1 ] ;"
@@ -86,7 +86,7 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertEqual(result.get("error"), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get("error"))
 
     def test_file_based_assert(self):
         self.file_paths = [('/tmp/test.txt', False)]
@@ -111,9 +111,8 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertTrue(result.get("success"))
-        self.assertEqual(result.get("error"), "Correct answer\n")
 
-class BashStdIOEvaluationTestCases(unittest.TestCase):
+class BashStdIOEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         self.in_dir = tempfile.mkdtemp()
         self.timeout_msg = ("Code took more than {0} seconds to run. "
@@ -147,7 +146,6 @@ class BashStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_array_input(self):
@@ -177,7 +175,6 @@ class BashStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -204,7 +201,7 @@ class BashStdIOEvaluationTestCases(unittest.TestCase):
 
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        self.assertIn("Incorrect", result.get('error'))
+        self.assert_correct_output("Incorrect", result.get('error'))
         self.assertFalse(result.get('success'))
 
     def test_stdout_only(self):
@@ -231,7 +228,6 @@ class BashStdIOEvaluationTestCases(unittest.TestCase):
 
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
 if __name__ == '__main__':
diff --git a/yaksh/evaluator_tests/test_c_cpp_evaluation.py b/yaksh/evaluator_tests/test_c_cpp_evaluation.py
index dc6fdc9..ec59a6b 100644
--- a/yaksh/evaluator_tests/test_c_cpp_evaluation.py
+++ b/yaksh/evaluator_tests/test_c_cpp_evaluation.py
@@ -9,11 +9,11 @@ from textwrap import dedent
 from yaksh.grader import Grader
 from yaksh.cpp_code_evaluator import CppCodeEvaluator
 from yaksh.cpp_stdio_evaluator import CppStdIOEvaluator
+from yaksh.evaluator_tests.test_python_evaluation import EvaluatorBaseTest
 from yaksh.settings import SERVER_TIMEOUT
 
 
-
-class CAssertionEvaluationTestCases(unittest.TestCase):
+class CAssertionEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         with open('/tmp/test.txt', 'wb') as f:
             f.write('2'.encode('ascii'))
@@ -48,7 +48,6 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertTrue(result.get('success'))
-        self.assertEqual(result.get('error'), "Correct answer\n")
 
     def test_incorrect_answer(self):
         user_answer = "int add(int a, int b)\n{return a-b;}"
@@ -65,9 +64,9 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        lines_of_error = len(result.get('error').splitlines())
+        lines_of_error = len(result.get('error')[0].splitlines())
         self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect:", result.get('error'))
+        self.assert_correct_output("Incorrect:", result.get('error'))
         self.assertTrue(lines_of_error > 1)
 
     def test_compilation_error(self):
@@ -86,7 +85,7 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertTrue("Compilation Error" in result.get("error"))
+        self.assert_correct_output("Compilation Error", result.get("error"))
 
     def test_infinite_loop(self):
         user_answer = "int add(int a, int b)\n{while(1>0){}}"
@@ -104,7 +103,7 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertEqual(result.get("error"), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get("error"))
 
     def test_file_based_assert(self):
         self.file_paths = [('/tmp/test.txt', False)]
@@ -138,9 +137,8 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertTrue(result.get('success'))
-        self.assertEqual(result.get('error'), "Correct answer\n")
 
-class CppStdIOEvaluationTestCases(unittest.TestCase):
+class CppStdIOEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         self.test_case_data = [{'expected_output': '11',
                                 'expected_input': '5\n6',
@@ -174,7 +172,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_array_input(self):
@@ -205,7 +202,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_string_input(self):
@@ -234,7 +230,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -257,9 +252,9 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        lines_of_error = len(result.get('error').splitlines())
+        lines_of_error = len(result.get('error')[0].splitlines())
         self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect", result.get('error'))
+        self.assert_correct_output("Incorrect", result.get('error'))
         self.assertTrue(lines_of_error > 1)
 
     def test_error(self):
@@ -283,7 +278,7 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertTrue("Compilation Error" in result.get("error"))
+        self.assert_correct_output("Compilation Error", result.get("error"))
 
     def test_infinite_loop(self):
         user_answer = dedent("""
@@ -306,7 +301,7 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertEqual(result.get("error"), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get("error"))
 
     def test_only_stdout(self):
         self.test_case_data = [{'expected_output': '11',
@@ -333,7 +328,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_cpp_correct_answer(self):
@@ -358,7 +352,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_cpp_array_input(self):
@@ -390,7 +383,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_cpp_string_input(self):
@@ -420,7 +412,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_cpp_incorrect_answer(self):
@@ -444,9 +435,9 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        lines_of_error = len(result.get('error').splitlines())
+        lines_of_error = len(result.get('error')[0].splitlines())
         self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect", result.get('error'))
+        self.assert_correct_output("Incorrect", result.get('error'))
         self.assertTrue(lines_of_error > 1)
 
     def test_cpp_error(self):
@@ -471,7 +462,7 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertTrue("Compilation Error" in result.get("error"))
+        self.assert_correct_output("Compilation Error", result.get("error"))
 
     def test_cpp_infinite_loop(self):
         user_answer = dedent("""
@@ -495,7 +486,7 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertEqual(result.get("error"), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get("error"))
 
     def test_cpp_only_stdout(self):
         self.test_case_data = [{'expected_output': '11',
@@ -523,7 +514,6 @@ class CppStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
 if __name__ == '__main__':
diff --git a/yaksh/evaluator_tests/test_java_evaluation.py b/yaksh/evaluator_tests/test_java_evaluation.py
index 36eb6a5..bfba38f 100644
--- a/yaksh/evaluator_tests/test_java_evaluation.py
+++ b/yaksh/evaluator_tests/test_java_evaluation.py
@@ -10,9 +10,10 @@ from yaksh import grader as gd
 from yaksh.grader import Grader
 from yaksh.java_code_evaluator import JavaCodeEvaluator
 from yaksh.java_stdio_evaluator import JavaStdIOEvaluator
+from yaksh.evaluator_tests.test_python_evaluation import EvaluatorBaseTest
 
 
-class JavaAssertionEvaluationTestCases(unittest.TestCase):
+class JavaAssertionEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         with open('/tmp/test.txt', 'wb') as f:
             f.write('2'.encode('ascii'))
@@ -51,7 +52,6 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -70,9 +70,9 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get('success'))
-        lines_of_error = len(result.get('error').splitlines())
+        lines_of_error = len(result.get('error')[0].splitlines())
         self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect", result.get('error'))
+        self.assert_correct_output("Incorrect", result.get('error'))
         self.assertTrue(lines_of_error > 1)
 
     def test_error(self):
@@ -91,7 +91,7 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertTrue("Error" in result.get("error"))
+        self.assert_correct_output("Error", result.get("error"))
 
     def test_infinite_loop(self):
         user_answer = "class Test {\n\tint square_num(int a) {\n\t\twhile(0==0){\n\t\t}\n\t}\n}"
@@ -109,7 +109,7 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertEqual(result.get("error"), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get("error"))
 
     def test_file_based_assert(self):
         self.file_paths = [("/tmp/test.txt", False)]
@@ -151,9 +151,8 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertTrue(result.get("success"))
-        self.assertEqual(result.get("error"), "Correct answer\n")
 
-class JavaStdIOEvaluationTestCases(unittest.TestCase):
+class JavaStdIOEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         with open('/tmp/test.txt', 'wb') as f:
             f.write('2'.encode('ascii'))
@@ -198,7 +197,6 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_array_input(self):
@@ -230,7 +228,6 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -256,9 +253,9 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        lines_of_error = len(result.get('error').splitlines())
+        lines_of_error = len(result.get('error')[0].splitlines())
         self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect", result.get('error'))
+        self.assert_correct_output("Incorrect", result.get('error'))
         self.assertTrue(lines_of_error > 1)
 
     def test_error(self):
@@ -281,7 +278,7 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertTrue("Compilation Error" in result.get("error"))
+        self.assertTrue("Compilation Error" in '\n'.join(result.get("error")))
 
     def test_infinite_loop(self):
         user_answer = dedent("""
@@ -305,7 +302,7 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertEqual(result.get("error"), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get("error"))
 
     def test_only_stdout(self):
         self.test_case_data = [{'expected_output': '11',
@@ -333,7 +330,6 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_string_input(self):
@@ -364,7 +360,6 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_file_based_stdout(self):
@@ -406,7 +401,6 @@ class JavaStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertTrue(result.get("success"))
-        self.assertEqual(result.get("error"), "Correct answer\n")
 
 
 if __name__ == '__main__':
diff --git a/yaksh/evaluator_tests/test_python_evaluation.py b/yaksh/evaluator_tests/test_python_evaluation.py
index e638049..c58d7f1 100644
--- a/yaksh/evaluator_tests/test_python_evaluation.py
+++ b/yaksh/evaluator_tests/test_python_evaluation.py
@@ -11,7 +11,14 @@ from yaksh.python_assertion_evaluator import PythonAssertionEvaluator
 from yaksh.python_stdio_evaluator import PythonStdIOEvaluator
 from yaksh.settings import SERVER_TIMEOUT
 
-class PythonAssertionEvaluationTestCases(unittest.TestCase):
+
+class EvaluatorBaseTest(unittest.TestCase):
+    def assert_correct_output(self, expected_output, actual_output):
+        actual_output_as_string = ''.join(actual_output)
+        self.assertIn(expected_output, actual_output_as_string)
+
+
+class PythonAssertionEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         with open('/tmp/test.txt', 'wb') as f:
             f.write('2'.encode('ascii'))
@@ -49,7 +56,6 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertTrue(result.get('success'))
-        self.assertIn("Correct answer", result.get('error'))
 
     def test_incorrect_answer(self):
         # Given
@@ -70,13 +76,13 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertFalse(result.get('success'))
-        self.assertIn('AssertionError  in: assert(add(1,2)==3)',
+        self.assert_correct_output('AssertionError  in: assert(add(1,2)==3)',
                         result.get('error')
                       )
-        self.assertIn('AssertionError  in: assert(add(-1,2)==1)',
+        self.assert_correct_output('AssertionError  in: assert(add(-1,2)==1)',
                         result.get('error')
                       )
-        self.assertIn('AssertionError  in: assert(add(-1,-2)==-3)',
+        self.assert_correct_output('AssertionError  in: assert(add(-1,-2)==-3)',
                         result.get('error')
                       )
 
@@ -104,10 +110,10 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # Then
         self.assertFalse(result.get('success'))
         self.assertEqual(result.get('weight'), 2.0)
-        self.assertIn('AssertionError  in: assert(add(-1,2)==1)',
+        self.assert_correct_output('AssertionError  in: assert(add(-1,2)==1)',
                         result.get('error')
                       )
-        self.assertIn('AssertionError  in: assert(add(-1,-2)==-3)',
+        self.assert_correct_output('AssertionError  in: assert(add(-1,-2)==-3)',
                         result.get('error')
                       )
 
@@ -130,7 +136,7 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertFalse(result.get('success'))
-        self.assertEqual(result.get('error'), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get('error'))
 
     def test_syntax_error(self):
         # Given
@@ -159,13 +165,14 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
+        error_as_str = ''.join(result.get("error"))
+        err = error_as_str.splitlines()
 
         # Then
         self.assertFalse(result.get("success"))
         self.assertEqual(5, len(err))
         for msg in syntax_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
     def test_indent_error(self):
         # Given
@@ -193,13 +200,13 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
+        err = result.get("error")[0].splitlines()
 
         # Then
         self.assertFalse(result.get("success"))
         self.assertEqual(5, len(err))
         for msg in indent_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
     def test_name_error(self):
         # Given
@@ -224,13 +231,14 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
+        error_as_str = ''.join(result.get("error"))
+        err = error_as_str.splitlines()
 
         # Then
         self.assertFalse(result.get("success"))
-        self.assertEqual(9, len(err))
+        self.assertEqual(6, len(err))
         for msg in name_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
     def test_recursion_error(self):
         # Given
@@ -256,12 +264,13 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
+        error_as_str = ''.join(result.get("error"))
+        err = error_as_str.splitlines()
 
         # Then
         self.assertFalse(result.get("success"))
         for msg in recursion_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
     def test_type_error(self):
         # Given
@@ -288,13 +297,14 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
+        error_as_str = ''.join(result.get("error"))
+        err = error_as_str.splitlines()
 
         # Then
         self.assertFalse(result.get("success"))
-        self.assertEqual(9, len(err))
+        self.assertEqual(6, len(err))
         for msg in type_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
     def test_value_error(self):
         # Given
@@ -323,13 +333,14 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
+        error_as_str = ''.join(result.get("error"))
+        err = error_as_str.splitlines()
 
         # Then
         self.assertFalse(result.get("success"))
-        self.assertEqual(9, len(err))
+        self.assertEqual(6, len(err))
         for msg in value_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
     def test_file_based_assert(self):
         # Given
@@ -356,7 +367,6 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         # Then
-        self.assertIn("Correct answer", result.get('error'))
         self.assertTrue(result.get('success'))
 
     def test_single_testcase_error(self):
@@ -378,8 +388,7 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
                             "invalid syntax"
                             ]
 
-        kwargs = {
-                  'metadata': {
+        kwargs = {'metadata': {
                     'user_answer': user_answer,
                     'file_paths': self.file_paths,
                     'partial_grading': False,
@@ -391,13 +400,14 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
-
+        error_as_str = ''.join(result.get("error"))
+        err = error_as_str.splitlines()
+        
         # Then
         self.assertFalse(result.get("success"))
-        self.assertEqual(6, len(err))
+        self.assertEqual(5, len(err))
         for msg in syntax_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
 
     def test_multiple_testcase_error(self):
@@ -432,15 +442,16 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         # When
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
-        err = result.get("error").splitlines()
+        error_as_str = ''.join(result.get("error"))
+        err = error_as_str.splitlines()
 
         # Then
         self.assertFalse(result.get("success"))
-        self.assertEqual(7, len(err))
+        self.assertEqual(2, len(err))
         for msg in name_error_msg:
-            self.assertIn(msg, result.get("error"))
+            self.assert_correct_output(msg, result.get("error"))
 
-class PythonStdIOEvaluationTestCases(unittest.TestCase):
+class PythonStdIOEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         with open('/tmp/test.txt', 'wb') as f:
             f.write('2'.encode('ascii'))
@@ -476,7 +487,6 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertTrue(result.get('success'))
-        self.assertIn("Correct answer", result.get('error'))
 
     def test_correct_answer_list(self):
         # Given
@@ -510,7 +520,6 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertTrue(result.get('success'))
-        self.assertIn("Correct answer", result.get('error'))
 
     def test_correct_answer_string(self):
         # Given
@@ -542,7 +551,6 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertTrue(result.get('success'))
-        self.assertIn("Correct answer", result.get('error'))
 
     def test_incorrect_answer_integer(self):
         # Given
@@ -572,7 +580,7 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect answer", result.get('error'))
+        self.assert_correct_output("Incorrect answer", result.get('error'))
 
     def test_file_based_answer(self):
         # Given
@@ -603,7 +611,6 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         # Then
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_infinite_loop(self):
@@ -632,7 +639,7 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         # Then
-        self.assertEqual(result.get('error'), timeout_msg)
+        self.assert_correct_output(timeout_msg, result.get('error'))
         self.assertFalse(result.get('success'))
 
 
diff --git a/yaksh/evaluator_tests/test_scilab_evaluation.py b/yaksh/evaluator_tests/test_scilab_evaluation.py
index 0275ee8..938d0e5 100644
--- a/yaksh/evaluator_tests/test_scilab_evaluation.py
+++ b/yaksh/evaluator_tests/test_scilab_evaluation.py
@@ -7,8 +7,10 @@ import tempfile
 from yaksh import grader as gd
 from yaksh.grader import Grader
 from yaksh.scilab_code_evaluator import ScilabCodeEvaluator
+from yaksh.evaluator_tests.test_python_evaluation import EvaluatorBaseTest
 
-class ScilabEvaluationTestCases(unittest.TestCase):
+
+class ScilabEvaluationTestCases(EvaluatorBaseTest):
     def setUp(self):
         tmp_in_dir_path = tempfile.mkdtemp()
         self.test_case_data = [{"test_case": "scilab_files/test_add.sce",
@@ -42,7 +44,6 @@ class ScilabEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        self.assertEqual(result.get('error'), "Correct answer\n")
         self.assertTrue(result.get('success'))
 
     def test_error(self):
@@ -62,7 +63,7 @@ class ScilabEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertTrue('error' in result.get("error"))
+        self.assert_correct_output('error', result.get("error"))
 
 
     def test_incorrect_answer(self):
@@ -81,9 +82,9 @@ class ScilabEvaluationTestCases(unittest.TestCase):
         grader = Grader(self.in_dir)
         result = grader.evaluate(kwargs)
 
-        lines_of_error = len(result.get('error').splitlines())
+        lines_of_error = len(result.get('error')[0].splitlines())
         self.assertFalse(result.get('success'))
-        self.assertIn("Message", result.get('error'))
+        self.assert_correct_output("Message", result.get('error'))
         self.assertTrue(lines_of_error > 1)
 
     def test_infinite_loop(self):
@@ -103,7 +104,7 @@ class ScilabEvaluationTestCases(unittest.TestCase):
         result = grader.evaluate(kwargs)
 
         self.assertFalse(result.get("success"))
-        self.assertEqual(result.get("error"), self.timeout_msg)
+        self.assert_correct_output(self.timeout_msg, result.get("error"))
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/yaksh/grader.py b/yaksh/grader.py
index ef349e0..0c057c2 100644
--- a/yaksh/grader.py
+++ b/yaksh/grader.py
@@ -24,7 +24,6 @@ from .language_registry import create_evaluator_instance
 
 
 MY_DIR = abspath(dirname(__file__))
-
 registry = None
 
 # Raised when the code times-out.
@@ -34,7 +33,7 @@ class TimeoutException(Exception):
 
 @contextlib.contextmanager
 def change_dir(path):
-    cur_dir = os.getcwd()
+    cur_dir = abspath(dirname(MY_DIR))
     os.chdir(path)
     try:
         yield
@@ -77,7 +76,7 @@ class Grader(object):
         self.in_dir = in_dir if in_dir else MY_DIR
 
 
-    def evaluate(self, kwargs): #language, test_case_type, 
+    def evaluate(self, kwargs):
         """Evaluates given code with the test cases based on
         given arguments in test_case_data.
 
@@ -96,9 +95,8 @@ class Grader(object):
         Returns
         -------
 
-        A tuple: (success, error message, weight).
+        A tuple: (success, error, weight).
         """
-
         self.setup()
         test_case_instances = self.get_evaluator_objects(kwargs)
         with change_dir(self.in_dir):
@@ -135,7 +133,7 @@ class Grader(object):
         prev_handler = create_signal_handler()
         success = False
         test_case_success_status = [False] * len(test_case_instances)
-        error = ""
+        error = []
         weight = 0.0
 
         # Do whatever testing needed.
@@ -147,8 +145,8 @@ class Grader(object):
                 test_case_success, err, mark_fraction = test_case_instance.check_code()
                 if test_case_success:
                     weight += mark_fraction
-
-                error += err + "\n"
+                else:
+                    error.append(err)
                 test_case_success_status[idx] = test_case_success
 
             success = all(test_case_success_status)
@@ -157,16 +155,16 @@ class Grader(object):
                 test_case_instance.teardown()
 
         except TimeoutException:
-            error = self.timeout_msg
+            error.append(self.timeout_msg)
         except OSError:
             msg = traceback.format_exc(limit=0)
-            error = "Error: {0}".format(msg)
-        except Exception as e:
+            error.append("Error: {0}".format(msg))
+        except Exception:
             exc_type, exc_value, exc_tb = sys.exc_info()
             tb_list = traceback.format_exception(exc_type, exc_value, exc_tb)
             if len(tb_list) > 2:
                 del tb_list[1:3]
-            error = "Error: {0}".format("".join(tb_list))
+            error.append("Error: {0}".format("".join(tb_list)))
         finally:
             # Set back any original signal handler.
             set_original_signal_handler(prev_handler)
diff --git a/yaksh/java_code_evaluator.py b/yaksh/java_code_evaluator.py
index 5d3fd28..91e5840 100644
--- a/yaksh/java_code_evaluator.py
+++ b/yaksh/java_code_evaluator.py
@@ -18,6 +18,7 @@ class JavaCodeEvaluator(BaseEvaluator):
         self.files = []
         self.compiled_user_answer = None
         self.compiled_test_code = None
+        self.submit_code_path = ""
         self.user_output_path = ""
         self.ref_output_path = ""
 
@@ -142,7 +143,7 @@ class JavaCodeEvaluator(BaseEvaluator):
                                          stderr=subprocess.PIPE)
                 proc, stdout, stderr = ret
                 if proc.returncode == 0:
-                    success, err = True, "Correct answer"
+                    success, err = True, None
                     mark_fraction = float(seelf.weight) if self.partial_grading else 0.0
                 else:
                     err = stdout + "\n" + stderr
diff --git a/yaksh/models.py b/yaksh/models.py
index 6e1744c..35999d3 100644
--- a/yaksh/models.py
+++ b/yaksh/models.py
@@ -1027,9 +1027,15 @@ class AnswerPaper(models.Model):
         for answer in self.answers.all():
             question = answer.question
             if question in q_a:
-                q_a[question].append(answer)
+                q_a[question].append({'answer': answer,
+                        'error_list': [e for e in json.loads(answer.error)]
+                    }
+                )
             else:
-                q_a[question] = [answer]
+                q_a[question] = [{'answer': answer,
+                        'error_list': [e for e in json.loads(answer.error)]
+                    }
+                ]
         return q_a
 
     def get_questions(self):
@@ -1064,20 +1070,20 @@ class AnswerPaper(models.Model):
             For code questions success is True only if the answer is correct.
         """
 
-        result = {'success': True, 'error': 'Incorrect answer', 'weight': 0.0}
+        result = {'success': True, 'error': ['Incorrect answer'], 'weight': 0.0}
         correct = False
         if user_answer is not None:
             if question.type == 'mcq':
                 expected_answer = question.get_test_case(correct=True).options
                 if user_answer.strip() == expected_answer.strip():
                     correct = True
-                    result['error'] = 'Correct answer'
+                    result['error'] = ['Correct answer']
             elif question.type == 'mcc':
                 expected_answers = []
                 for opt in question.get_test_cases(correct=True):
                     expected_answers.append(opt.options)
                 if set(user_answer) == set(expected_answers):
-                    result['error'] = 'Correct answer'
+                    result['error'] = ['Correct answer']
                     correct = True
             elif question.type == 'code':
                 user_dir = self.user.profile.get_user_dir()
@@ -1155,9 +1161,7 @@ class StandardTestCase(TestCase):
                 "weight": self.weight}
 
     def __str__(self):
-        return u'Question: {0} | Test Case: {1}'.format(self.question,
-            self.test_case
-        )
+        return u'Standard TestCase | Test Case: {0}'.format(self.test_case)
 
 
 class StdIOBasedTestCase(TestCase):
@@ -1172,7 +1176,7 @@ class StdIOBasedTestCase(TestCase):
                "weight": self.weight}
 
     def __str__(self):
-        return u'Question: {0} | Exp. Output: {1} | Exp. Input: {2}'.format(self.question,
+        return u'StdIO Based Testcase | Exp. Output: {0} | Exp. Input: {1}'.format(
             self.expected_output, self.expected_input
         )
 
@@ -1185,9 +1189,7 @@ class McqTestCase(TestCase):
         return {"test_case_type": "mcqtestcase", "options": self.options, "correct": self.correct}
 
     def __str__(self):
-        return u'Question: {0} | Correct: {1}'.format(self.question,
-            self.correct
-        )
+        return u'MCQ Testcase | Correct: {0}'.format(self.correct)
 
 
 class HookTestCase(TestCase):
diff --git a/yaksh/python_assertion_evaluator.py b/yaksh/python_assertion_evaluator.py
index 4d44838..749a6ec 100644
--- a/yaksh/python_assertion_evaluator.py
+++ b/yaksh/python_assertion_evaluator.py
@@ -75,9 +75,14 @@ class PythonAssertionEvaluator(BaseEvaluator):
             type, value, tb = sys.exc_info()
             info = traceback.extract_tb(tb)
             fname, lineno, func, text = info[-1]
-            text = str(self.test_case).splitlines()[lineno-1]
-            err = ("-----\nExpected Test Case:\n{0}\n"
-                    "Error - {1} {2} in: {3}\n-----").format(self.test_case, type.__name__, str(value), text)
+            text = str(self.test_case)
+            err = "Expected Test Case:\n{0}\n" \
+                "Error - {1} {2} in: {3}\n".format(
+                    self.test_case,
+                    type.__name__,
+                    str(value),
+                    text
+                    )
         except TimeoutException:
             raise
         except Exception:
@@ -85,7 +90,7 @@ class PythonAssertionEvaluator(BaseEvaluator):
             err = "Error in Test case: {0}".format(msg)
         else:
             success = True
-            err = '-----\nCorrect answer\nTest Case: {0}\n-----'.format(self.test_case)
+            err = None
             mark_fraction = float(self.weight) if self.partial_grading else 0.0
         del tb
         return success, err, mark_fraction
diff --git a/yaksh/python_stdio_evaluator.py b/yaksh/python_stdio_evaluator.py
index da0c954..67f57a9 100644
--- a/yaksh/python_stdio_evaluator.py
+++ b/yaksh/python_stdio_evaluator.py
@@ -70,7 +70,7 @@ class PythonStdIOEvaluator(BaseEvaluator):
         tb = None
         if self.output_value == self.expected_output:
             success = True
-            err = "Correct answer"
+            err = None
             mark_fraction = self.weight
         else:
             success = False
diff --git a/yaksh/scilab_code_evaluator.py b/yaksh/scilab_code_evaluator.py
index cc3c401..bf16c84 100644
--- a/yaksh/scilab_code_evaluator.py
+++ b/yaksh/scilab_code_evaluator.py
@@ -69,7 +69,7 @@ class ScilabCodeEvaluator(BaseEvaluator):
             # Clean output
             stdout = self._strip_output(stdout)
             if proc.returncode == 5:
-                success, err = True, "Correct answer"
+                success, err = True, None
                 test_case_weight = float(self.weight) if self.partial_grading else 0.0
             else:
                 err = add_err + stdout
diff --git a/yaksh/stdio_evaluator.py b/yaksh/stdio_evaluator.py
index 106facd..fb9dfb3 100644
--- a/yaksh/stdio_evaluator.py
+++ b/yaksh/stdio_evaluator.py
@@ -21,7 +21,7 @@ class StdIOEvaluator(BaseEvaluator):
                         format(expected_input, repr(expected_output))
         if output_err == '':
             if user_output == expected_output:
-                success, err = True, "Correct answer"
+                success, err = True, None
             else:
                 err = " Incorrect answer\n" + error_msg +\
                       "\n Your output is {0}".format(repr(user_output))
diff --git a/yaksh/templates/yaksh/grade_user.html b/yaksh/templates/yaksh/grade_user.html
index 38f31ca..6fb8187 100644
--- a/yaksh/templates/yaksh/grade_user.html
+++ b/yaksh/templates/yaksh/grade_user.html
@@ -118,6 +118,7 @@ Status : <b style="color: green;"> Passed </b><br/>
     method="post">
 {% csrf_token %}
 {% for question, answers in paper.get_question_answers.items %}
+
 <div class="panel panel-info">
         <div class="panel-heading">
             <strong> Details: {{forloop.counter}}. {{ question.summary }} 
@@ -134,44 +135,31 @@ Status : <b style="color: green;"> Passed </b><br/>
             {% else %}
                 <h5> <u>Test cases: </u></h5>
                     {% for testcase in question.get_test_cases %}
-                        <br/><strong>{{ forloop.counter }}. {{ testcase.test_case }}</strong>
+                        <br/><strong>{{ forloop.counter }}. {{ testcase }}</strong>
                     {% endfor %}
             {%endif%}
         </div>
     </div>
-    {% if question.type == "mcq" or question.type == "mcc" %}
-        {% if "Correct answer" in answers.0.error %}
-            <div class="panel panel-success">
-        {% else %}
-            <div class="panel panel-danger">
-        {% endif %}
-            <div class="panel-heading">
-                Autocheck: {{ answers.0.error }}
-            </div>
-            <div class="panel-body">
-                <h5><u>Student answer:</u></h5>
-                 <pre><code>{{forloop.counter}}. {{ answers.0 }}</code></pre>
-            </div>
-            </div>
-    {% else %}
     <h5>Student answer: </h5>
-    {% for answer in answers %}
-    {% if not answer.skipped %}
-    {% if answer.correct %}
+    {% for ans in answers %}
+    {% if ans.answer.correct %}
             <div class="panel panel-success">
+                <div class="panel-heading">Correct:
         {% else %}
             <div class="panel panel-danger">
+                <div class="panel-heading">Error:
         {% endif %}
-    <div class="panel-heading">Autocheck: {{ answer.error }}</div>
-    <div class="panel-body"><pre><code>{{ answer.answer.strip }}</code></pre></div>
+        {% for err in ans.error_list %}
+            <div><pre>{{ err }}</pre></div>
+        {% endfor %}
+    </div>
+    <div class="panel-body"><pre><code>{{ ans.answer.answer.strip }}</code></pre></div>
     </div>
-    {% endif %}
     {% endfor %}
-    {% endif %}
     {% with answers|last as answer %}
     Marks: <input id="q{{ question.id }}" type="text" 
         name="q{{ question.id }}_marks" size="4"
-        value="{{ answer.marks }}"><br><br>
+        value="{{ answer.0.marks }}"><br><br>
     {% endwith %}
     <hr/>
     {% endfor %} {# for question, answers ... #}
diff --git a/yaksh/templates/yaksh/question.html b/yaksh/templates/yaksh/question.html
index 74ac786..0279f0d 100644
--- a/yaksh/templates/yaksh/question.html
+++ b/yaksh/templates/yaksh/question.html
@@ -162,16 +162,32 @@ function call_skip(url)
                  <div class="panel-body">
                      {% if question.type == "mcq" %}
                     {% if error_message %}
-                        <p>{{ error_message }}</p>
-                    {% endif %}
+                        <p>
+                        <div class="panel panel-danger">
+                        <div class="panel-heading">
+                        {% for err in error_message %}
+                            {{ err }}
+                        {% endfor %}
+                        </div>
+                        </div>
+                        </p>
+                     {% endif %}
                      {% for test_case in test_cases %}
                      <input name="answer" type="radio" value="{{ test_case.options }}" />{{ test_case.options }} <br/>
                      {% endfor %}
                      {% endif %}
                      {% if question.type == "mcc" %}
                     {% if error_message %}
-                        <p>{{ error_message }}</p>
-                    {% endif %}
+                        <p>
+                        <div class="panel panel-danger">
+                        <div class="panel-heading">
+                        {% for err in error_message %}
+                            {{ err }}
+                        {% endfor %}
+                        </div>
+                        </div>
+                        </p>
+                     {% endif %}
                      {% for test_case in test_cases %}
                      <input name="answer" type="checkbox" value="{{ test_case.options }}"> {{ test_case.options }}
                      <br>
@@ -209,11 +225,19 @@ function call_skip(url)
          </div>
      {% if question.type == "code" %}
                      <div class="panel-footer">
+
      {% if error_message %}
-         <p> Output Message</p>
-         <div class="alert alert-danger" role="alert">
-        <textarea style="width:100%" class="error" readonly="yes">{{ error_message }}</textarea>
-         </div>
+      {% for error in error_message %}
+      {% if error == "Correct answer" %}
+              <div class="panel panel-success">
+          {% else %}
+              <div class="panel panel-danger">
+          {% endif %}
+      <div class="panel-heading">Testcase No. {{ forloop.counter }}</div>
+      <div class="panel-body"><pre><code>{{ error }}</code></pre></div>
+      </div>
+      {% endfor %}
+
       {% endif %}
      </div>
      {% endif %}
diff --git a/yaksh/templates/yaksh/user_data.html b/yaksh/templates/yaksh/user_data.html
index 378e7fd..856433d 100644
--- a/yaksh/templates/yaksh/user_data.html
+++ b/yaksh/templates/yaksh/user_data.html
@@ -99,7 +99,13 @@ User IP address: {{ paper.user_ip }}
         {% else %}
             <div class="panel panel-danger">
         {% endif %}
-    <div class="panel-heading">Autocheck: {{ answer.error }}</div>
+    <div class="panel-heading">
+        {% for error in error %}
+        <div class="panel-body">
+            <pre><code>{{ error }}</code></pre>
+        </div>
+        {% endfor %}
+    </div>
     <div class="panel-body"><pre><code>{{ answer.answer.strip }}</code></pre></div>
     </div>
     {% endif %}
diff --git a/yaksh/test_models.py b/yaksh/test_models.py
index 317c832..6764dd0 100644
--- a/yaksh/test_models.py
+++ b/yaksh/test_models.py
@@ -487,12 +487,14 @@ class AnswerPaperTestCases(unittest.TestCase):
         # answers for the Answer Paper
         self.answer_right = Answer(question=Question.objects.get(id=1),
             answer="Demo answer",
-            correct=True, marks=1
+            correct=True, marks=1,
+            error=json.dumps([])
         )
         self.answer_wrong = Answer(question=Question.objects.get(id=2),
             answer="My answer",
             correct=False,
-            marks=0
+            marks=0,
+            error=json.dumps(['error1', 'error2'])
         )
         self.answer_right.save()
         self.answer_wrong.save()
@@ -550,7 +552,7 @@ class AnswerPaperTestCases(unittest.TestCase):
         # Then
         self.assertTrue(correct)
         self.assertTrue(result['success'])
-        self.assertEqual(result['error'], 'Correct answer')
+        self.assertEqual(result['error'], ['Correct answer'])
         self.answer.correct = True
         self.answer.marks = 1
 
@@ -587,7 +589,6 @@ class AnswerPaperTestCases(unittest.TestCase):
         # Then
         self.assertTrue(correct)
         self.assertTrue(result['success'])
-        self.assertEqual(result['error'], 'Correct answer')
         self.answer.correct = True
         self.answer.marks = 1
 
@@ -729,8 +730,9 @@ class AnswerPaperTestCases(unittest.TestCase):
         """ Test get_question_answer() method of Answer Paper"""
         answered = self.answerpaper.get_question_answers()
         first_answer = list(answered.values())[0][0]
-        self.assertEqual(first_answer.answer, 'Demo answer')
-        self.assertTrue(first_answer.correct)
+        first_answer_obj = first_answer['answer']
+        self.assertEqual(first_answer_obj.answer, 'Demo answer')
+        self.assertTrue(first_answer_obj.correct)
         self.assertEqual(len(answered), 2)
 
     def test_is_answer_correct(self):
diff --git a/yaksh/tests/test_code_server.py b/yaksh/tests/test_code_server.py
index d46c9dd..19698a5 100644
--- a/yaksh/tests/test_code_server.py
+++ b/yaksh/tests/test_code_server.py
@@ -55,7 +55,7 @@ class TestCodeServer(unittest.TestCase):
         # Then
         data = json.loads(result)
         self.assertFalse(data['success'])
-        self.assertTrue('infinite loop' in data['error'])
+        self.assertTrue('infinite loop' in data['error'][0])
 
     def test_correct_answer(self):
         # Given
@@ -77,7 +77,6 @@ class TestCodeServer(unittest.TestCase):
         # Then
         data = json.loads(result)
         self.assertTrue(data['success'])
-        self.assertIn('Correct answer', data['error'])
 
     def test_wrong_answer(self):
         # Given
@@ -99,7 +98,7 @@ class TestCodeServer(unittest.TestCase):
         # Then
         data = json.loads(result)
         self.assertFalse(data['success'])
-        self.assertTrue('AssertionError' in data['error'])
+        self.assertTrue('AssertionError' in data['error'][0])
 
     def test_multiple_simultaneous_hits(self):
         # Given
@@ -139,7 +138,7 @@ class TestCodeServer(unittest.TestCase):
         for i in range(N):
             data = results.get()
             self.assertFalse(data['success'])
-            self.assertTrue('infinite loop' in data['error'])
+            self.assertTrue('infinite loop' in data['error'][0])
 
     def test_server_pool_status(self):
         # Given
diff --git a/yaksh/views.py b/yaksh/views.py
index 89274df..7ecf6aa 100644
--- a/yaksh/views.py
+++ b/yaksh/views.py
@@ -430,7 +430,8 @@ def skip(request, q_id, next_q=None, attempt_num=None, questionpaper_id=None):
     if request.method == 'POST' and question.type == 'code':
         user_code = request.POST.get('answer')
         new_answer = Answer(question=question, answer=user_code,
-                            correct=False, skipped=True)
+                            correct=False, skipped=True,
+                            error=json.dumps([]))
         new_answer.save()
         paper.answers.add(new_answer)
     if next_q is not None:
@@ -448,69 +449,68 @@ def check(request, q_id, attempt_num=None, questionpaper_id=None):
     user = request.user
     paper = get_object_or_404(AnswerPaper, user=request.user, attempt_number=attempt_num,
             question_paper=questionpaper_id)
-    question = get_object_or_404(Question, pk=q_id)
-    if question in paper.questions_answered.all():
+    current_question = get_object_or_404(Question, pk=q_id)
+    if current_question in paper.questions_answered.all():
         next_q = paper.next_question(q_id)
         return show_question(request, next_q, paper)
 
     if request.method == 'POST':
         snippet_code = request.POST.get('snippet')
         # Add the answer submitted, regardless of it being correct or not.
-        if question.type == 'mcq':
+        if current_question.type == 'mcq':
             user_answer = request.POST.get('answer')
-        elif question.type == 'mcc':
+        elif current_question.type == 'mcc':
             user_answer = request.POST.getlist('answer')
-        elif question.type == 'upload':
+        elif current_question.type == 'upload':
             assign = AssignmentUpload()
             assign.user = user.profile
-            assign.assignmentQuestion = question
+            assign.assignmentQuestion = current_question
             # if time-up at upload question then the form is submitted without
             # validation
             if 'assignment' in request.FILES:
                 assign.assignmentFile = request.FILES['assignment']
             assign.save()
             user_answer = 'ASSIGNMENT UPLOADED'
-            next_q = paper.completed_question(question.id)
+            next_q = paper.completed_question(current_question.id)
             return show_question(request, next_q, paper)
         else:
             user_code = request.POST.get('answer')
             user_answer = snippet_code + "\n" + user_code if snippet_code else user_code
-        new_answer = Answer(question=question, answer=user_answer,
-                            correct=False)
+        if not user_answer:
+            msg = ["Please submit a valid option or code"]
+            return show_question(request, current_question, paper, msg)
+        new_answer = Answer(question=current_question, answer=user_answer,
+                            correct=False, error=json.dumps([]))
         new_answer.save()
         paper.answers.add(new_answer)
-        if not user_answer:
-            msg = "Please submit a valid option or code"
-            return show_question(request, question, paper, msg)
         # If we were not skipped, we were asked to check.  For any non-mcq
         # questions, we obtain the results via XML-RPC with the code executed
         # safely in a separate process (the code_server.py) running as nobody.
-        json_data = question.consolidate_answer_data(user_answer) \
-                        if question.type == 'code' else None
-        correct, result = paper.validate_answer(user_answer, question, json_data)
-        if correct:
-            new_answer.marks = (question.points * result['weight'] / 
-                question.get_maximum_test_case_weight()) \
-                if question.partial_grading and question.type == 'code' else question.points
+        json_data = current_question.consolidate_answer_data(user_answer) \
+                        if current_question.type == 'code' else None
+        correct, result = paper.validate_answer(user_answer, current_question, json_data)
+        if correct or result.get('success'):
+            new_answer.marks = (current_question.points * result['weight'] / 
+                current_question.get_maximum_test_case_weight()) \
+                if current_question.partial_grading and current_question.type == 'code' else current_question.points
             new_answer.correct = correct
-            new_answer.error = result.get('error')
+            error_message = None
+            new_answer.error = json.dumps(result.get('error'))
+            next_question = paper.completed_question(current_question.id)
         else:
-            new_answer.error = result.get('error')
-            new_answer.marks = (question.points * result['weight'] /
-                question.get_maximum_test_case_weight()) \
-                if question.partial_grading and question.type == 'code' else 0
+            new_answer.marks = (current_question.points * result['weight'] /
+                current_question.get_maximum_test_case_weight()) \
+                if current_question.partial_grading and current_question.type == 'code' else 0
+            error_message = result.get('error')
+            new_answer.error = json.dumps(result.get('error'))
+            next_question = current_question if current_question.type == 'code' \
+                else paper.completed_question(current_question.id)
         new_answer.save()
         paper.update_marks('inprogress')
         paper.set_end_time(timezone.now())
-        if not result.get('success'):  # Should only happen for non-mcq questions.
-            new_answer.answer = user_code
-            new_answer.save()
-            return show_question(request, question, paper, result.get('error'))
-        else:
-            next_q = paper.completed_question(question.id)
-            return show_question(request, next_q, paper)
+        return show_question(request, next_question, paper, error_message)
     else:
-        return show_question(request, question, paper)
+        return show_question(request, current_question, paper)
 
 
 
@@ -1036,7 +1036,7 @@ def grade_user(request, quiz_id=None, user_id=None, attempt_number=None):
             user = User.objects.get(id=user_id)
             data = AnswerPaper.objects.get_user_data(user, questionpaper_id,
                                                      attempt_number
-                                                     )
+                                                    )
 
             context = {'data': data, "quiz_id": quiz_id, "users": user_details,
                     "attempts": attempts, "user_id": user_id
@@ -1044,7 +1044,7 @@ def grade_user(request, quiz_id=None, user_id=None, attempt_number=None):
     if request.method == "POST":
         papers = data['papers']
         for paper in papers:
-            for question, answers in six.iteritems(paper.get_question_answers()):
+            for question, answers, errors in six.iteritems(paper.get_question_answers()):
                 marks = float(request.POST.get('q%d_marks' % question.id, 0))
                 answers = answers[-1]
                 answers.set_marks(marks)
diff --git a/yaksh/xmlrpc_clients.py b/yaksh/xmlrpc_clients.py
index bb8260d..fbcd6a5 100644
--- a/yaksh/xmlrpc_clients.py
+++ b/yaksh/xmlrpc_clients.py
@@ -69,7 +69,8 @@ class CodeServerProxy(object):
         except ConnectionError:
             result = json.dumps({'success': False,
                 'weight': 0.0,
-                'error': 'Unable to connect to any code servers!'})
+                'error': ['Unable to connect to any code servers!']
+                })
         return result
 
     def _get_server(self):