feat(api): query command builder (#3085)

renku/command/command_builder/command.py

@@ -22,7 +22,7 @@
 import threading
 from collections import defaultdict
 from pathlib import Path
-from typing import Any, Callable, Dict, List, Optional, Union
+from typing import Any, Callable, Dict, List, Optional, Type, Union
 
 import inject
 
@@ -270,6 +270,23 @@ def finalized(self) -> bool:
             return self._builder.finalized
         return self._finalized
 
+    def any_builder_is_instance_of(self, cls: Type) -> bool:
+        """Check if any 'chained' command builder is an instance of a specific command builder class."""
+        if isinstance(self, cls):
+            return True
+        elif "_builder" in self.__dict__:
+            return self._builder.any_builder_is_instance_of(cls)
+        else:
+            return False
+
+    @property
+    def will_write_to_database(self) -> bool:
+        """Will running the command write anything to the metadata store."""
+        try:
+            return self._write
+        except AttributeError:
+            return False
+
     @check_finalized
     def add_injection_pre_hook(self, order: int, hook: Callable):
         """Add a pre-execution hook for dependency injection.

tests/command_builder/test_command.py

@@ -0,0 +1,43 @@
+from typing import Type
+
+import pytest
+
+from renku.command.command_builder import Command
+from renku.command.command_builder.database import DatabaseCommand
+from renku.command.command_builder.repo import Commit, Isolation, RequireClean
+
+
+@pytest.mark.parametrize(
+    "input,cls,expected",
+    [
+        (Command(), Command, True),
+        (Command(), DatabaseCommand, False),
+        (Command().with_git_isolation(), Isolation, True),
+        (Command().with_git_isolation(), RequireClean, False),
+        (Command().with_git_isolation().with_commit(), Command, True),
+        (Command().with_git_isolation().with_commit(), Isolation, True),
+        (Command().with_git_isolation().with_commit(), Commit, True),
+        (Command().with_git_isolation().with_commit(), DatabaseCommand, False),
+        (Command().with_git_isolation().with_commit().with_database(), DatabaseCommand, True),
+    ],
+)
+def test_any_builder_is_instance_of(input: Command, cls: Type, expected: bool):
+    assert input.any_builder_is_instance_of(cls) == expected
+
+
+@pytest.mark.parametrize(
+    "input,expected",
+    [
+        (Command(), False),
+        (Command().with_git_isolation(), False),
+        (Command().with_git_isolation().with_commit(), False),
+        (Command().with_git_isolation().with_commit().with_database(write=True), True),
+        (Command().with_git_isolation().with_commit().with_database(write=False), False),
+        (Command().with_database(write=True), True),
+        (Command().with_database(write=False), False),
+        (Command().with_git_isolation().with_database(write=True).with_commit(), True),
+        (Command().with_git_isolation().with_database(write=False).with_commit(), False),
+    ],
+)
+def test_will_write_to_database(input: Command, expected: bool):
+    assert input.will_write_to_database == expected