add basic test infrastructure

conftest.py

@@ -0,0 +1,3 @@
+pytest_plugins = [
+    'mypy.test.data'
+]

pytest.ini

@@ -0,0 +1,7 @@
+[pytest]
+
+testpaths = test
+python_files = test*.py
+addopts =
+    -nauto
+    --tb=native

test/test-data/basic-check.test

@@ -0,0 +1,9 @@
+[case testBasicCheck]
+from typing import Any
+
+class A:
+    pass
+
+class B(A):
+    pass
+[out]

test/testdjango.py

@@ -0,0 +1,48 @@
+import os
+import sys
+from pathlib import Path
+
+from mypy import api
+from mypy.test.config import test_temp_dir
+from mypy.test.data import DataSuite, DataDrivenTestCase
+from mypy.test.helpers import assert_string_arrays_equal
+
+ROOT_DIR = Path(__file__).parent.parent
+TEST_DATA_DIR = ROOT_DIR / 'test' / 'test-data'
+
+
+class DjangoTestSuite(DataSuite):
+    files = [
+        'basic-check.test'
+    ]
+    data_prefix = str(TEST_DATA_DIR)
+
+    def run_case(self, testcase: DataDrivenTestCase) -> None:
+        assert testcase.old_cwd is not None, "test was not properly set up"
+
+        mypy_cmdline = []
+        mypy_cmdline.append('--python-version={}'.format('.'.join(map(str,
+                                                                      sys.version_info[:2]))))
+
+        program_path = os.path.join(test_temp_dir, 'main.py')
+        mypy_cmdline.append(program_path)
+
+        with open(program_path, 'w') as file:
+            for s in testcase.input:
+                file.write('{}\n'.format(s))
+
+        output = []
+        # Type check the program.
+        out, err, returncode = api.run(mypy_cmdline)
+        # split lines, remove newlines, and remove directory of test case
+        for line in (out + err).splitlines():
+            if line.startswith(test_temp_dir + os.sep):
+                output.append(line[len(test_temp_dir + os.sep):].rstrip("\r\n").replace('.py', ''))
+            else:
+                output.append(line.rstrip("\r\n"))
+        # Remove temp file.
+        os.remove(program_path)
+
+        assert_string_arrays_equal(testcase.output, output,
+                                   'Invalid output ({}, line {})'.format(
+                                       testcase.file, testcase.line))