Implement pyre coverage (2/3) -- find root

Reviewed By: kbansal

Differential Revision: D30436429

fbshipit-source-id: 08e5f08061994cecd8f3c4eaea6b7a98d343dc37

Author: grievejia

client/commands/v2/coverage.py

@@ -4,17 +4,31 @@
 # LICENSE file in the root directory of this source tree.
 
 import logging
+from pathlib import Path
 
 from ... import commands, configuration as configuration_module
-from . import remote_logging
+from . import remote_logging, statistics
 
 LOG: logging.Logger = logging.getLogger(__name__)
 
 
+def find_root(
+    configuration: configuration_module.Configuration, working_directory: Path
+) -> Path:
+    local_root = configuration.local_root
+    if local_root is not None:
+        return Path(local_root)
+
+    return working_directory
+
+
 def run_coverage(
     configuration: configuration_module.Configuration, working_directory: str
 ) -> commands.ExitCode:
-    LOG.warning("Coming soon...")
+    sources = statistics.find_paths_to_parse(
+        [find_root(configuration, Path(working_directory))]
+    )
+    LOG.warning(f"SOURCES = {list(sources)}")
     return commands.ExitCode.SUCCESS
 
 

client/commands/v2/tests/coverage_test.py

@@ -0,0 +1,35 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+from pathlib import Path
+
+import testslide
+
+from .... import configuration
+from ..coverage import find_root
+
+
+class CoverageTest(testslide.TestCase):
+    def test_find_root(self) -> None:
+        self.assertEqual(
+            find_root(
+                configuration.Configuration(
+                    project_root="/root",
+                    dot_pyre_directory=Path("/irrelevant"),
+                    relative_local_root="local",
+                ),
+                working_directory=Path("/irrelevant"),
+            ),
+            Path("/root/local"),
+        )
+        self.assertEqual(
+            find_root(
+                configuration.Configuration(
+                    project_root="/root", dot_pyre_directory=Path("/irrelevant")
+                ),
+                working_directory=Path("/working/dir"),
+            ),
+            Path("/working/dir"),
+        )