chore: enable RUF100 and clear unused noqa directives (#8546)

Follow-up to review on #8540, where a stale `# noqa: E402` slipped past
me and Sydney spotted it by eye. This turns on the rule that catches
that automatically.

`RUF100` flags a `noqa` that suppresses nothing. `sdk-py` already had it
through its blanket `RUF` selection; this adds it to the other seven
packages and clears what it finds.

### The 33 it flags, all autofixed

**Blanket `# noqa` on docstring-closing lines** (4, in
`checkpoint-postgres` and `checkpoint-sqlite`). `E501` is in
`lint.ignore` for those packages, so nothing was being suppressed:

```diff
-        """  # noqa
+        """
```

**`# noqa: F821` on `anext(aiter_)`** (2). Left over from Python 3.9
support. `anext` became a builtin in 3.10, which is the floor now, so
`F821` no longer fires:

```diff
-                    anext(aiter_),  # type: ignore[arg-type]  # noqa: F821
+                    anext(aiter_),  # type: ignore[arg-type]
```

**Suppressions naming rules the package does not enable** (27), across
`langgraph`, `prebuilt` and `checkpoint-sqlite`: `FBT001`, `FBT002`,
`TC002`, `BLE001`, `ANN001`, `ANN002`, `ANN003`, `E501`, `F401`. Mostly
copied between packages whose rule sets differ.

### One measurement note

If you check these numbers yourself, use `--extend-select`:

```
ruff check --select RUF100 .          # 81, misleading
ruff check --extend-select RUF100 .   # 33, real
```

With a bare `--select`, ruff treats every other rule as disabled, so
every suppression for another rule looks unused. I quoted 81 before
catching that.

### Verified

`checkpoint-sqlite` 118 passed, `prebuilt` 284 passed, `langgraph` 1968
passed, `checkpoint-postgres` 264 passed on PG 15 and 16. `make lint`
clean in every package.

Independent of #8540 and #8537, so it can land in any order.

libs/checkpoint-conformance/pyproject.toml

@@ -58,6 +58,7 @@ lint.select = [
   "UP", # pyupgrade
   "B",  # flake8-bugbear
   "I",  # isort
+  "RUF100",  # unused noqa directive
 ]
 lint.ignore = ["E501", "B008"]
 target-version = "py310"

libs/checkpoint-postgres/langgraph/checkpoint/postgres/__init__.py

@@ -223,7 +223,7 @@ class PostgresSaver(BasePostgresSaver):
             >>> checkpoint_tuple = memory.get_tuple(config)
             >>> print(checkpoint_tuple)
             CheckpointTuple(...)
-        """  # noqa
+        """
         thread_id = config["configurable"]["thread_id"]
         checkpoint_id = get_checkpoint_id(config)
         checkpoint_ns = config["configurable"].get("checkpoint_ns", "")

libs/checkpoint-postgres/langgraph/checkpoint/postgres/aio.py

@@ -573,7 +573,7 @@ class AsyncPostgresSaver(BasePostgresSaver):
         while True:
             try:
                 yield asyncio.run_coroutine_threadsafe(
-                    anext(aiter_),  # type: ignore[arg-type]  # noqa: F821
+                    anext(aiter_),  # type: ignore[arg-type]
                     self.loop,
                 ).result()
             except StopAsyncIteration:

libs/checkpoint-postgres/langgraph/checkpoint/postgres/shallow.py

@@ -334,7 +334,7 @@ class ShallowPostgresSaver(BasePostgresSaver):
             >>> checkpoint_tuple = memory.get_tuple(config)
             >>> print(checkpoint_tuple)
             CheckpointTuple(...)
-        """  # noqa
+        """
         thread_id = config["configurable"]["thread_id"]
         checkpoint_ns = config["configurable"].get("checkpoint_ns", "")
         args = (thread_id, checkpoint_ns)
@@ -885,7 +885,7 @@ class AsyncShallowPostgresSaver(BasePostgresSaver):
         while True:
             try:
                 yield asyncio.run_coroutine_threadsafe(
-                    anext(aiter_),  # type: ignore[arg-type]  # noqa: F821
+                    anext(aiter_),  # type: ignore[arg-type]
                     self.loop,
                 ).result()
             except StopAsyncIteration:

libs/checkpoint-postgres/pyproject.toml

@@ -65,6 +65,7 @@ lint.select = [
   "B",  # flake8-bugbear
   "I",  # isort
   "PLC0415",  # import-outside-top-level
+  "RUF100",  # unused noqa directive
   "UP", # pyupgrade
 ]
 lint.ignore = ["E501", "B008"]

libs/checkpoint-sqlite/langgraph/checkpoint/sqlite/__init__.py

@@ -77,7 +77,7 @@ class SqliteSaver(BaseCheckpointSaver[str]):
         >>> result = graph.invoke(3, config)
         >>> graph.get_state(config)
         StateSnapshot(values=4, next=(), config={'configurable': {'thread_id': '1', 'checkpoint_ns': '', 'checkpoint_id': '0c62ca34-ac19-445d-bbb0-5b4984975b2a'}}, parent_config=None)
-    """  # noqa
+    """
 
     conn: sqlite3.Connection
     is_setup: bool
@@ -222,7 +222,7 @@ class SqliteSaver(BaseCheckpointSaver[str]):
             >>> checkpoint_tuple = memory.get_tuple(config)
             >>> print(checkpoint_tuple)
             CheckpointTuple(...)
-        """  # noqa
+        """
         checkpoint_ns = config["configurable"].get("checkpoint_ns", "")
         with self.cursor(transaction=False) as cur:
             # find the latest checkpoint for the thread_id

libs/checkpoint-sqlite/langgraph/checkpoint/sqlite/aio.py

@@ -212,7 +212,7 @@ class AsyncSqliteSaver(BaseCheckpointSaver[str]):
         while True:
             try:
                 yield asyncio.run_coroutine_threadsafe(
-                    anext(aiter_),  # type: ignore[arg-type]  # noqa: F821
+                    anext(aiter_),  # type: ignore[arg-type]
                     self.loop,
                 ).result()
             except StopAsyncIteration:

libs/checkpoint-sqlite/pyproject.toml

@@ -63,6 +63,7 @@ lint.select = [
   "B",  # flake8-bugbear
   "I",  # isort
   "PLC0415",  # import-outside-top-level
+  "RUF100",  # unused noqa directive
   "UP", # pyupgrade
 ]
 lint.ignore = ["E501", "B008"]

libs/checkpoint-sqlite/tests/test_conformance_delta.py

@@ -10,10 +10,10 @@ pytest.importorskip(
 )
 pytest.importorskip("aiosqlite", reason="aiosqlite not installed")
 
-from langgraph.checkpoint.conformance import validate  # noqa: E402
-from langgraph.checkpoint.conformance.initializer import checkpointer_test  # noqa: E402
+from langgraph.checkpoint.conformance import validate
+from langgraph.checkpoint.conformance.initializer import checkpointer_test
 
-from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver  # noqa: E402
+from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver
 
 
 @pytest.mark.asyncio

libs/checkpoint-sqlite/tests/test_delta_channel_migration.py

@@ -29,13 +29,13 @@ pytest.importorskip("langgraph.channels.delta", reason="langgraph core not insta
 pytest.importorskip("langgraph.channels.binop", reason="langgraph core not installed")
 pytest.importorskip("langgraph.graph", reason="langgraph core not installed")
 
-from langgraph.channels.binop import BinaryOperatorAggregate  # type: ignore[import-untyped]  # noqa: E402,I001
-from langgraph.channels.delta import DeltaChannel  # type: ignore[import-untyped]  # noqa: E402
-from langgraph.graph import END, START, StateGraph  # type: ignore[import-untyped]  # noqa: E402
-from typing_extensions import TypedDict  # noqa: E402
+from langgraph.channels.binop import BinaryOperatorAggregate  # type: ignore[import-untyped]  # noqa: I001
+from langgraph.channels.delta import DeltaChannel  # type: ignore[import-untyped]
+from langgraph.graph import END, START, StateGraph  # type: ignore[import-untyped]
+from typing_extensions import TypedDict
 
-from langgraph.checkpoint.sqlite import SqliteSaver  # noqa: E402
-from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver  # noqa: E402
+from langgraph.checkpoint.sqlite import SqliteSaver
+from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver
 
 pytestmark = pytest.mark.anyio
 

libs/checkpoint-sqlite/tests/test_get_delta_channel_history.py

@@ -32,13 +32,13 @@ from langchain_core.runnables import RunnableConfig
 pytest.importorskip("langgraph.channels.delta", reason="langgraph core not installed")
 pytest.importorskip("langgraph.graph", reason="langgraph core not installed")
 
-from langgraph.channels.delta import DeltaChannel  # type: ignore[import-untyped]  # noqa: E402,I001
-from langgraph.checkpoint.serde.types import _DeltaSnapshot  # noqa: E402
-from langgraph.graph import END, START, StateGraph  # type: ignore[import-untyped]  # noqa: E402
-from typing_extensions import TypedDict  # noqa: E402
+from langgraph.channels.delta import DeltaChannel  # type: ignore[import-untyped]  # noqa: I001
+from langgraph.checkpoint.serde.types import _DeltaSnapshot
+from langgraph.graph import END, START, StateGraph  # type: ignore[import-untyped]
+from typing_extensions import TypedDict
 
-from langgraph.checkpoint.sqlite import SqliteSaver  # noqa: E402
-from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver  # noqa: E402
+from langgraph.checkpoint.sqlite import SqliteSaver
+from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver
 
 pytestmark = pytest.mark.anyio
 

libs/checkpoint/pyproject.toml

@@ -59,6 +59,7 @@ lint.select = [
   "UP", # pyupgrade
   "B",  # flake8-bugbear
   "I",  # isort
+  "RUF100",  # unused noqa directive
   "UP", # pyupgrade
 ]
 lint.ignore = ["E501", "B008"]

libs/cli/pyproject.toml

@@ -72,6 +72,7 @@ lint.select = [
   "UP", # pyupgrade
   "B",  # flake8-bugbear
   "I",  # isort
+  "RUF100",  # unused noqa directive
   "UP", # pyupgrade
 ]
 lint.ignore = ["E501", "B008"]

libs/langgraph/langgraph/_internal/_pydantic.py

@@ -68,7 +68,7 @@ def _create_root_model(
 
     def schema(
         cls: type[BaseModel],
-        by_alias: bool = True,  # noqa: FBT001,FBT002
+        by_alias: bool = True,
         ref_template: str = DEFAULT_REF_TEMPLATE,
     ) -> dict[str, Any]:
         # Complains about schema not being defined in superclass
@@ -80,7 +80,7 @@ def _create_root_model(
 
     def model_json_schema(
         cls: type[BaseModel],
-        by_alias: bool = True,  # noqa: FBT001,FBT002
+        by_alias: bool = True,
         ref_template: str = DEFAULT_REF_TEMPLATE,
         schema_generator: type[GenerateJsonSchema] = GenerateJsonSchema,
         mode: JsonSchemaMode = "validation",

libs/langgraph/langgraph/_internal/_serde.py

@@ -22,7 +22,7 @@ from pydantic import BaseModel
 from typing_extensions import NotRequired, Required, is_typeddict
 
 try:
-    from langgraph.checkpoint.serde._msgpack import (  # noqa: F401
+    from langgraph.checkpoint.serde._msgpack import (
         STRICT_MSGPACK_ENABLED,
     )
 except ImportError:

libs/langgraph/langgraph/errors.py

@@ -7,7 +7,7 @@ from typing import Any, Literal
 from warnings import warn
 
 # EmptyChannelError is re-exported from langgraph.channels.base
-from langgraph.checkpoint.base import EmptyChannelError  # noqa: F401
+from langgraph.checkpoint.base import EmptyChannelError
 from typing_extensions import deprecated
 
 from langgraph.types import Command, Interrupt

libs/langgraph/langgraph/graph/state.py

@@ -995,7 +995,7 @@ class StateGraph(Generic[StateT, ContextT, InputT, OutputT]):
             Without type hints on the `path` function's return value (e.g., `-> Literal["foo", "__end__"]:`)
             or a path_map, the graph visualization assumes the edge could transition to any node in the graph.
 
-        """  # noqa: E501
+        """
         if self.compiled:
             logger.warning(
                 "Adding an edge to a graph that has already been compiled. This will "

libs/langgraph/pyproject.toml

@@ -89,7 +89,7 @@ langgraph-sdk = { path = "../sdk-py", editable = true }
 langgraph-cli = { path = "../cli", editable = true }
 
 [tool.ruff]
-lint.select = [ "E", "F", "I", "TID251", "UP" ]
+lint.select = [ "E", "F", "I", "RUF100", "TID251", "UP" ]
 lint.ignore = [ "E501" ]
 line-length = 88
 indent-width = 4

libs/langgraph/tests/test_config_async.py

@@ -24,7 +24,7 @@ class _TrackingCallback(BaseCallbackHandler):
     def __init__(self) -> None:
         self.called = False
 
-    def on_chain_start(self, *args, **kwargs) -> None:  # noqa: ANN002, ANN003
+    def on_chain_start(self, *args, **kwargs) -> None:
         self.called = True
 
 
@@ -55,7 +55,7 @@ async def test_with_config_configurable_preserved_on_invoke() -> None:
     builder = StateGraph(dict)
     captured: dict = {}
 
-    def node(state, config):  # noqa: ANN001
+    def node(state, config):
         captured.update(config.get("configurable") or {})
         return state
 
@@ -79,7 +79,7 @@ async def test_with_config_metadata_preserved_on_invoke() -> None:
     builder = StateGraph(dict)
     captured: dict = {}
 
-    def node(state, config):  # noqa: ANN001
+    def node(state, config):
         captured.update(config.get("metadata") or {})
         return state
 
@@ -104,7 +104,7 @@ async def test_with_config_tags_preserved_on_invoke() -> None:
     builder = StateGraph(dict)
     captured: list = []
 
-    def node(state, config):  # noqa: ANN001
+    def node(state, config):
         captured.extend(config.get("tags") or [])
         return state
 

libs/prebuilt/langgraph/prebuilt/tool_node.py

@@ -87,8 +87,8 @@ from langgraph._internal._runnable import RunnableCallable
 from langgraph.errors import GraphBubbleUp
 from langgraph.graph.message import REMOVE_ALL_MESSAGES
 from langgraph.pregel._tools import _tool_call_writer
-from langgraph.runtime import ExecutionInfo, ServerInfo  # noqa: TC002
-from langgraph.store.base import BaseStore  # noqa: TC002
+from langgraph.runtime import ExecutionInfo, ServerInfo
+from langgraph.store.base import BaseStore
 from langgraph.types import Command, Send, StreamWriter
 from pydantic import BaseModel, ValidationError
 from typing_extensions import TypeVar, Unpack
@@ -332,7 +332,7 @@ def msg_content_output(output: Any) -> str | list[dict]:
     # any existing ToolNode usage.
     try:
         return json.dumps(output, ensure_ascii=False)
-    except Exception:  # noqa: BLE001
+    except Exception:
         return str(output)
 
 
@@ -736,7 +736,7 @@ class ToolNode(RunnableCallable):
 
         tool_node = ToolNode([my_tool], handle_tool_errors=handle_errors)
         ```
-    """  # noqa: E501
+    """
 
     name: str = "tools"
 

libs/prebuilt/pyproject.toml

@@ -75,7 +75,7 @@ addopts = "--strict-markers --strict-config --durations=5 -vv"
 asyncio_mode = "auto"
 
 [tool.ruff]
-lint.select = [ "E", "F", "I", "TID251", "UP" ]
+lint.select = [ "E", "F", "I", "RUF100", "TID251", "UP" ]
 lint.ignore = [ "E501" ]
 target-version = "py310"
 

libs/prebuilt/tests/test_on_tool_call.py

@@ -1338,7 +1338,7 @@ def _config_with_channel_read(
 
     # Shape matches pregel's real partial:
     # functools.partial(local_read, scratchpad, channels, managed, task)
-    def _read(scratchpad, channels, managed, task, select, fresh):  # noqa: ARG001
+    def _read(scratchpad, channels, managed, task, select, fresh):
         if isinstance(select, str):
             return channel_values[select]
         return {k: channel_values[k] for k in select if k in channel_values}