Add support for systems that lack gcc/g++/java

autograder/__main__.py

@@ -47,6 +47,14 @@ def main(argv=None):
     if args.version:
         print(__version__)
         exit(0)
+    if sys.platform.startswith("win32"):
+        print(
+            "Windows is not supported by autograder. If you do not have Linux,"
+            "try using it through utilities like Windows Subsystem For Linux."
+        )
+        exit(1)
+    elif sys.platform.startswith("darwin"):
+        print("OSX is not officially supported. Proceed with caution.")
     try:
         grader = Grader(
             current_dir,

autograder/__version__.py

@@ -1,6 +1,6 @@
 __title__ = "assignment-autograder"
 __description__ = "Automatic assignment grading for instructor use in programming courses"
-__version__ = "2.11.1"
+__version__ = "2.12.0"
 __author__ = "Stanislav Zmiev"
 __author_email__ = "[email protected]"
 __license__ = "MIT"

autograder/config_manager.py

@@ -81,7 +81,7 @@ def _figure_out_testcase_types(self) -> Dict[str, Type[TestCase]]:
         if testcase_types:
             return testcase_types
         else:
-            raise AutograderError(f"Couldn't discover a testcase with correct suffix in {self.testcases_dir}")
+            raise AutograderError(f"Couldn't discover a testcase with supported suffix in {self.testcases_dir}")
 
 
 T = TypeVar("T")

autograder/grader.py

@@ -117,7 +117,7 @@ def _gather_testcases(self) -> List[testcases.TestCase]:
             arglist = self.config._generate_arglists(test.name)
             shutil.copy(test, self.paths.temp_dir)
             tests.append(
-                testcase_type(
+                testcase_type(  # type: ignore # The typing error here appears due to the limitations of python's typing
                     self.paths.temp_dir / test.name,
                     self.config.source_file_name,
                     self.paths.input_dir,
@@ -189,6 +189,8 @@ def _get_testcase_output(self, submission: Path, student_dir: Path, logger: Buff
         total_testcase_score = 0
         testcase_results = []
         allowed_tests = [t for t in self.tests if t.source_suffix == submission.suffix]
+        if not allowed_tests:
+            print(f"No testcases suitable for the submission {submission.name} found.")
         if any(isinstance(t, JavaTestCase) for t in allowed_tests):
             JavaTestCase.run_additional_testcase_operations_in_student_dir(student_dir)
         for test in allowed_tests:

autograder/testcases/__init__.py

@@ -1,12 +1,25 @@
+from typing import Dict, Type
 from .abstract_base_class import ArgList, TestCase
 from .c import CTestCase
 from .cpp import CPPTestCase
 from .java import JavaTestCase
 from .python import PythonTestCase
 
-ALLOWED_LANGUAGES = {
+
+def _is_installed(language_name: str, testcase: TestCase) -> bool:
+    """ Useful for logging """
+    if testcase.is_installed():
+        return True
+    else:
+        print(f"Utilities for running {language_name} are not installed. Disabling it.")
+        return False
+
+
+ALLOWED_LANGUAGES: Dict[str, Type[TestCase]] = {
     "c": CTestCase,
     "java": JavaTestCase,
     "python": PythonTestCase,
     "c++": CPPTestCase,
-}
+}
+
+ALLOWED_LANGUAGES = {k: v for k, v in ALLOWED_LANGUAGES.items() if _is_installed(k, v)}

autograder/testcases/abstract_base_class.py

@@ -8,7 +8,7 @@
 import sh
 from typing_extensions import Protocol
 
-# TODO: I hate these imports. We should only use relative imports because these imports indicate architectural problems.
+# TODO: I hate these imports. We should only use relative imports because direct imports indicate architectural problems.
 from autograder.util import format_template, get_stderr
 
 from .util.exit_codes import USED_EXIT_CODES, ExitCodeEventType, ExitCodeHandler
@@ -24,6 +24,11 @@ def __call__(self, *args: str, **kwargs: Any) -> Optional[sh.RunningCommand]:
         raise NotImplementedError()
 
 
+def Command(command: str, *args: Any, **kwargs: Any) -> Optional[sh.Command]:
+    """ An API for commands that do not throw errors on creation """
+    return None if shutil.which(command) is None else sh.Command(command, *args, **kwargs)
+
+
 class ArgList(enum.Enum):
     SUBMISSION_PRECOMPILATION = "SUBMISSION_PRECOMPILATION_ARGS"
     TESTCASE_PRECOMPILATION = "TESTCASE_PRECOMPILATION_ARGS"
@@ -51,6 +56,11 @@ def compile_testcase(self, precompiled_submission: Path) -> ShCommand:
         pwd = temp/student_dir
         """
 
+    @classmethod
+    @abstractmethod
+    def is_installed(cls) -> bool:
+        """ Returns True software necessary to run the testcase is installed on the system """
+
     def __init__(
         self,
         path: Path,

autograder/testcases/c.py

@@ -3,21 +3,19 @@
 
 import sh
 
-from .abstract_base_class import ArgList, ShCommand, TestCase
-
-
-if shutil.which("gcc") is not None:
-    COMPILER = sh.Command("gcc")
-else:
-    COMPILER = None
+from .abstract_base_class import ArgList, Command, ShCommand, TestCase
 
 
 class CTestCase(TestCase):
     source_suffix = ".c"
     executable_suffix = ".out"
     helper_module_name = "test_helper.c"
     SUBMISSION_COMPILATION_ARGS = ("-Dscanf_s=scanf", "-Dmain=__student_main__")
-    compiler = COMPILER
+    compiler = Command("gcc")
+
+    @classmethod
+    def is_installed(cls) -> bool:
+        return cls.compiler is not None
 
     @classmethod
     def precompile_submission(cls, submission: Path, student_dir: Path, source_file_name: str, arglist):

autograder/testcases/cpp.py

@@ -1,14 +1,10 @@
+from autograder.testcases.abstract_base_class import Command
 import shutil
 import sh
 
 from .c import CTestCase
 
-if shutil.which("g++") is not None:
-    COMPILER = sh.Command("g++")
-else:
-    COMPILER = None
-
 
 class CPPTestCase(CTestCase):
     source_suffix = ".cpp"
-    compiler = COMPILER
+    compiler = Command("g++")

autograder/testcases/java.py

@@ -6,23 +6,13 @@
 
 from autograder.util import AutograderError
 
-from .abstract_base_class import ArgList, TestCase, TEST_HELPERS_DIR
+from .abstract_base_class import ArgList, Command, TestCase, TEST_HELPERS_DIR
 
 PUBLIC_CLASS_MATCHER = re.compile(r"public(?:\w|\s)+class(?:\w|\s)+({)")
 JNA_FILE_NAME = "jna.jar"
 PATH_TO_JNA_FILE = TEST_HELPERS_DIR / "extra" / JNA_FILE_NAME
 
 
-if shutil.which("javac") is not None:
-    COMPILER = sh.Command("javac")
-else:
-    COMPILER = None
-if shutil.which("java") is not None:
-    VM = sh.Command("java")
-else:
-    VM = None
-
-
 class JavaTestCase(TestCase):
     """Please, ask students to remove their main as it can theoretically
     generate errors (not sure how though).
@@ -33,8 +23,12 @@ class JavaTestCase(TestCase):
     source_suffix = ".java"
     executable_suffix = ""
     helper_module_name = "TestHelper.java"
-    compiler = COMPILER
-    virtual_machine = VM
+    compiler = Command("javac")
+    virtual_machine = Command("java")
+
+    @classmethod
+    def is_installed(cls) -> bool:
+        return cls.compiler is not None and cls.virtual_machine is not None
 
     @classmethod
     def precompile_submission(cls, submission: Path, student_dir: Path, source_file_name: str, arglist):

autograder/testcases/python.py

@@ -4,7 +4,7 @@
 
 import sh
 
-from .abstract_base_class import ArgList, TestCase
+from .abstract_base_class import ArgList, Command, TestCase
 
 import sys
 
@@ -24,7 +24,11 @@ class PythonTestCase(TestCase):
     source_suffix = ".py"
     executable_suffix = ".pyc"
     helper_module_name = "test_helper.py"
-    interpreter = sh.Command(PYTHON_EXECUTABLE_NAME)
+    interpreter = Command(PYTHON_EXECUTABLE_NAME)
+
+    @classmethod
+    def is_installed(cls) -> bool:
+        return cls.interpreter is not None
 
     @classmethod
     def precompile_submission(cls, submission: Path, student_dir: Path, source_file_name, arglist) -> Path: