WIP PE get_errors_slice. added tests to robot server

api/src/opentrons/protocol_engine/__init__.py

@@ -18,7 +18,15 @@
     CommandType,
     CommandIntent,
 )
-from .state import State, StateView, StateSummary, CommandSlice, CommandPointer, Config, CommandErrorSlice
+from .state import (
+    State,
+    StateView,
+    StateSummary,
+    CommandSlice,
+    CommandPointer,
+    Config,
+    CommandErrorSlice,
+)
 from .plugins import AbstractPlugin
 
 from .types import (

api/src/opentrons/protocol_engine/state/commands.py

@@ -116,6 +116,7 @@ class CommandSlice:
     cursor: int
     total_length: int
 
+
 @dataclass(frozen=True)
 class CommandErrorSlice:
     """A subset of all commands errors in state."""
@@ -627,6 +628,39 @@ def get_slice(
             total_length=total_length,
         )
 
+    def get_errors_slice(
+        self,
+        cursor: Optional[int],
+        length: int,
+    ) -> CommandErrorSlice:
+        """Get a subset of commands error around a given cursor.
+
+        If the cursor is omitted, a cursor will be selected automatically
+        based most recent error.
+        """
+        all_errors = self.get_all_errors()
+        total_length = len(all_errors)
+
+        if cursor is None:
+            if len(all_errors) > 0:
+                # Get the most recent error,
+                # which we can find just at the end of the list.
+                cursor = total_length - 1
+            else:
+                cursor = total_length - length
+
+        # start is inclusive, stop is exclusive
+        actual_cursor = max(0, min(cursor, total_length - 1))
+        stop = min(total_length, actual_cursor + length)
+
+        sliced_errors = all_errors[actual_cursor:stop]
+
+        return CommandErrorSlice(
+            commands_errors=sliced_errors,
+            cursor=actual_cursor,
+            total_length=total_length,
+        )
+
     def get_error(self) -> Optional[ErrorOccurrence]:
         """Get the run's fatal error, if there was one."""
         run_error = self._state.run_error

api/src/opentrons/protocol_runner/run_orchestrator.py

@@ -21,6 +21,7 @@
     StateSummary,
     CommandPointer,
     CommandSlice,
+    CommandErrorSlice,
     DeckType,
 )
 from ..protocol_engine.errors import RunStoppedError
@@ -269,6 +270,21 @@ def get_command_slice(
             cursor=cursor, length=length
         )
 
+    def get_command_error_slice(
+        self,
+        cursor: Optional[int],
+        length: int,
+    ) -> CommandErrorSlice:
+        """Get a slice of run commands.
+
+        Args:
+            cursor: Requested index of first command in the returned slice.
+            length: Length of slice to return.
+        """
+        return self._protocol_engine.state_view.commands.get_slice(
+            cursor=cursor, length=length
+        )
+
     def get_command_recovery_target(self) -> Optional[CommandPointer]:
         """Get the current error recovery target."""
         return self._protocol_engine.state_view.commands.get_recovery_target()

robot-server/robot_server/runs/router/commands_router.py

@@ -481,7 +481,9 @@ async def get_run_commands_error(
         __root__=command_error_slice.commands_errors
     )
     return await PydanticResponse.create(
-        content=SimpleMultiBody.construct(data=commands_errors_result, meta=meta),
+        content=SimpleMultiBody.construct(
+            data=commands_errors_result, meta=meta  # type: ignore[arg-type]
+        ),
         status_code=status.HTTP_200_OK,
     )
 

robot-server/tests/runs/router/test_commands_router.py

@@ -14,7 +14,7 @@
 )
 
 from robot_server.errors.error_responses import ApiError
-from robot_server.service.json_api import MultiBodyMeta, SimpleMultiBody
+from robot_server.service.json_api import MultiBodyMeta, SimpleMultiBody, ResponseList
 
 from robot_server.runs.command_models import (
     RequestModelWithCommandCreate,
@@ -24,7 +24,7 @@
 )
 from robot_server.runs.run_store import CommandNotFoundError, RunStore
 from robot_server.runs.run_orchestrator_store import RunOrchestratorStore
-from robot_server.runs.run_data_manager import RunDataManager
+from robot_server.runs.run_data_manager import RunDataManager, RunNotCurrentError
 from robot_server.runs.run_models import RunCommandSummary, RunNotFoundError
 from robot_server.runs.router.commands_router import (
     create_run_command,
@@ -448,6 +448,29 @@ async def test_get_run_commands_errors(
 ) -> None:
     """It should return a list of all commands errors in a run."""
 
+    decoy.when(
+        mock_run_data_manager.get_command_error_slice(
+            run_id="run-id",
+            cursor=None,
+            length=42,
+        )
+    ).then_raise(RunNotCurrentError("oh no!"))
+
+    with pytest.raises(ApiError):
+        result = await get_run_commands_error(
+            runId="run-id",
+            run_data_manager=mock_run_data_manager,
+            cursor=None,
+            pageLength=42,
+        )
+        assert result.status_code == 409
+
+
+async def test_get_run_commands_errors_raises_no_run(
+    decoy: Decoy, mock_run_data_manager: RunDataManager
+) -> None:
+    """It should return a list of all commands errors in a run."""
+
     error = (
         pe_errors.ErrorOccurrence(
             id="error-id",
@@ -458,7 +481,7 @@ async def test_get_run_commands_errors(
     )
 
     command_error_slice = CommandErrorSlice(
-        cursor=1, total_length=3, commands_errors=[error]
+        cursor=1, total_length=3, commands_errors=list(error)
     )
 
     decoy.when(
@@ -476,14 +499,16 @@ async def test_get_run_commands_errors(
         pageLength=42,
     )
 
-    assert result.content.data == [
-        pe_errors.ErrorOccurrence(
-            id="error-id",
-            errorType="PrettyBadError",
-            createdAt=datetime(year=2024, month=4, day=4),
-            detail="Things are not looking good.",
-        )
-    ]
+    assert result.content.data == ResponseList(
+        __root__=[
+            pe_errors.ErrorOccurrence(
+                id="error-id",
+                errorType="PrettyBadError",
+                createdAt=datetime(year=2024, month=4, day=4),
+                detail="Things are not looking good.",
+            )
+        ]
+    )
     assert result.content.meta == MultiBodyMeta(cursor=1, totalLength=3)
     assert result.status_code == 200
 

robot-server/tests/runs/test_run_data_manager.py

@@ -856,7 +856,7 @@ def test_get_commands_errors_slice__not_current_run_raises(
     decoy.when(mock_run_orchestrator_store.current_run_id).then_return("run-not-id")
 
     with pytest.raises(RunNotCurrentError):
-        result = subject.get_commands_slice("run-id", 1, 2)
+        result = subject.get_command_error_slice("run-id", 1, 2)
 
 
 def test_get_commands_errors_slice_current_run(