Code review - code refactoring as per suggestion

- Add subclasses for different languages
- Create seperate modules for different languages
- Dynamic selection of subclasses based on language used
- Add testcases

1 files changed, 128 insertions, 0 deletions

diff --git a/testapp/exam/evaluate_c.py b/testapp/exam/evaluate_c.py
new file mode 100644
index 0000000..93c3725
--- /dev/null
+++ b/testapp/exam/evaluate_c.py
@@ -0,0 +1,128 @@
+#!/usr/bin/env python
+import traceback
+import pwd
+import os
+from os.path import join, isfile
+import subprocess
+import importlib
+
+# local imports
+from code_server import TestCode
+
+class EvaluateC(TestCode):
+    """Tests the C code obtained from Code Server"""
+    def evaluate_code(self):
+        submit_path = self._create_submit_code_file('submit.c')
+        get_ref_path = self.ref_code_path
+        ref_path, test_case_path = self._set_test_code_file_path(get_ref_path)
+        success = False
+
+        # Set file paths
+        c_user_output_path = os.getcwd() + '/output',
+        c_ref_output_path = os.getcwd() + '/executable',
+
+        # Set command variables
+        compile_command = 'g++  {0} -c -o {1}'.format(submit_path,
+                                                    c_user_output_path),
+        compile_main = 'g++ {0} {1} -o {2}'.format(ref_path,
+                                                c_user_output_path,
+                                                c_ref_output_path),
+        run_command_args = c_ref_output_path
+        remove_user_output = c_user_output_path
+        remove_ref_output = c_ref_output_path
+
+        success, err = self.check_code(ref_path, submit_path, compile_command,
+                                     compile_main, run_command_args,
+                                     remove_user_output, remove_ref_output)
+
+        # Delete the created file.
+        os.remove(submit_path)
+
+        return success, err
+
+    def check_code(self, ref_code_path, submit_code_path, compile_command,
+                     compile_main, run_command_args, remove_user_output,
+                     remove_ref_output):
+        """ Function validates student code using instructor code as
+        reference.The first argument ref_code_path, is the path to
+        instructor code, it is assumed to have executable permission.
+        The second argument submit_code_path, is the path to the student
+        code, it is assumed to have executable permission.
+
+        Returns
+        --------
+
+        returns (True, "Correct answer") : If the student function returns
+        expected output when called by reference code.
+
+        returns (False, error_msg): If the student function fails to return
+        expected output when called by reference code.
+
+        Returns (False, error_msg): If mandatory arguments are not files or
+        if the required permissions are not given to the file(s).
+
+        """
+
+        if not isfile(ref_code_path):
+            return False, "No file at %s or Incorrect path" % ref_code_path
+        if not isfile(submit_code_path):
+            return False, 'No file at %s or Incorrect path' % submit_code_path
+
+        success = False
+        # output_path = os.getcwd() + '/output'
+        ret = self._compile_command(compile_command)
+        proc, stdnt_stderr = ret
+        # if self.language == "java":
+        stdnt_stderr = self._remove_null_substitute_char(stdnt_stderr)
+
+        # Only if compilation is successful, the program is executed
+        # And tested with testcases
+        if stdnt_stderr == '':
+            ret = self._compile_command(compile_main)
+            proc, main_err = ret
+            # if self.language == "java":
+            # main_err = self._remove_null_substitute_char(main_err)
+
+            if main_err == '':
+                ret = self._run_command(run_command_args, stdin=None,
+                                        stdout=subprocess.PIPE,
+                                        stderr=subprocess.PIPE)
+                proc, stdout, stderr = ret
+                if proc.returncode == 0:
+                    success, err = True, "Correct answer"
+                else:
+                    err = stdout + "\n" + stderr
+                os.remove(remove_ref_output)
+            else:
+                err = "Error:"
+                try:
+                    error_lines = main_err.splitlines()
+                    for e in error_lines:
+                        if ':' in e:
+                            err = err + "\n" + e.split(":", 1)[1]
+                        else:
+                            err = err + "\n" + e
+                except:
+                        err = err + "\n" + main_err
+            os.remove(remove_user_output)
+        else:
+            err = "Compilation Error:"
+            try:
+                error_lines = stdnt_stderr.splitlines()
+                for e in error_lines:
+                    if ':' in e:
+                        err = err + "\n" + e.split(":", 1)[1]
+                    else:
+                        err = err + "\n" + e
+            except:
+                err = err + "\n" + stdnt_stderr
+
+        return success, err
+
+    def _remove_null_substitute_char(self, string):
+        """Returns a string without any null and substitute characters"""
+        stripped = ""
+        for c in string:
+            if ord(c) is not 26 and ord(c) is not 0:
+                stripped = stripped + c
+        return ''.join(stripped)