fix(unittest): correct args for tests/classes/files (#2)

* fix: unittest adapter can run specific tests/groups/files

* fix: running tests at the directory level

* refactor: tidy id_to_unittest_args and remove print

neotest_python/unittest.py

@@ -1,4 +1,6 @@
 import inspect
+import os
+import sys
 import traceback
 import unittest
 from pathlib import Path
@@ -24,6 +26,22 @@ class UnittestNeotestAdapter(NeotestAdapter):
     def case_id(self, case: "TestCase | TestSuite") -> str:
         return "::".join(self.case_id_elems(case))
 
+    def id_to_unittest_args(self, case_id: str) -> List[str]:
+        """Converts a neotest ID into test specifier for unittest"""
+        path, *child_ids = case_id.split("::")
+        if not child_ids:
+            if os.path.isfile(path):
+                # Test files can be passed directly to unittest
+                return [path]
+            # Directories need to be run via the 'discover' argument
+            return ["discover", "-s", path]
+
+        # Otherwise, convert the ID into a dotted path, relative to current dir
+        relative_file = os.path.relpath(path, os.getcwd())
+        relative_stem = os.path.splitext(relative_file)[0]
+        relative_dotted = relative_stem.replace(os.sep, ".")
+        return [".".join([relative_dotted, *child_ids])]
+
     def run(self, args: List[str]) -> Dict:
         results = {}
 
@@ -71,9 +89,13 @@ class UnittestNeotestAdapter(NeotestAdapter):
                     }
                 return result
 
+        # Make sure we can import relative to current path
+        sys.path.insert(0, os.getcwd())
+        # We only get a single case ID as the argument
+        argv = sys.argv[0:1] + self.id_to_unittest_args(args[0])
         unittest.main(
             module=None,
-            argv=args,
+            argv=argv,
             testRunner=NeotestUnittestRunner(resultclass=NeotestTextTestResult),
             exit=False,
         )