Bump ruff floor to 0.16.0 and adopt its default rule set

CHANGES

@@ -23,6 +23,33 @@ Workflow actions moved to their current major releases: `actions/checkout` v7,
 and `dorny/paths-filter` v4. Workflow behavior is unchanged, though setup-uv no
 longer prunes the uv cache, so the first run after this repopulates it.
 
+**Minimum `ruff>=0.16.0`** (was unpinned)
+
+The `dev` and `lint` dependency groups now require ruff 0.16.0 or newer, so
+contributors and CI see the same diagnostics rather than whichever ruff each
+machine resolved. From this release on, `ruff format` also formats Python code
+blocks inside Markdown, so `uv run ruff format .` reaches the README and the
+`docs/` tree. Neither the lint nor the format change rewrites anything here.
+(#113)
+
+**ruff's curated default rule set is now enabled**
+
+`[tool.ruff.lint]` layers this project's linters on with `extend-select` instead
+of `select`. An explicit `select` replaces ruff's default set rather than adding
+to it, so the project had been silently opting out of every rule it did not name
+itself; enabled rules go from 351 to 565. The findings that surfaced are fixed —
+`re.DOTALL` spelled out in place of `re.S`, `str.removesuffix` and `min()` in
+`scripts/mcp_swap.py`, the server instruction blob built as an f-string, and the
+wrapped marker fixtures parenthesized so a dropped comma can no longer pass for
+a deliberate join. `scripts/mcp_swap.py` is now executable and its shebang points
+at `uv run --script`, so running it directly honours the PEP 723 metadata instead
+of failing to import `tomlkit` under a bare `python3`. Two rules are scoped
+ignores with their reasons recorded in
+`pyproject.toml`: `exec` in `docs/conf.py`, which is how Sphinx reads version
+metadata, and the `except Exception` boundaries in the error middleware, the
+batch runners, the best-effort tmux probes, and `mcp_swap`'s config rollback.
+(#113)
+
 ## libtmux-mcp 0.1.0a19 (2026-07-25)
 
 libtmux-mcp 0.1.0a19 makes {tooliconl}`wait-for-text` see the output it was asked to watch for, and puts a ceiling under every wait. The tool anchored one row below the cursor's position at entry, which on a quiescent pane is exactly where the next line lands, so the case it exists for — output you did not author, a daemon printing a single `ready` line — could not match at all. Waits are now bounded by a server ceiling, cancellable without orphaning their tmux child, and report an `outcome` that distinguishes a command that never ran from output that did not match from a pager owning the pane. The wait API changes shape in the process: `pattern` becomes `patterns`, `stop` markers end a wait early, and `wait_for_content_change` is removed in favour of `wait_for_text(patterns=null)`.

pyproject.toml

@@ -77,7 +77,7 @@ dev = [
   "coverage",
   "pytest-cov",
   # Lint
-  "ruff",
+  "ruff>=0.16.0",
   "mypy",
 ]
 
@@ -103,7 +103,7 @@ coverage =[
 ]
 lint = [
   "typing-extensions; python_version < '3.11'",
-  "ruff",
+  "ruff>=0.16.0",
   "mypy",
 ]
 
@@ -188,7 +188,10 @@ exclude_lines = [
 target-version = "py310"
 
 [tool.ruff.lint]
-select = [
+# `select` is deliberately unset: ruff 0.16 enables a curated default rule
+# set, and an explicit `select` would replace it rather than extend it.
+# `extend-select` layers this project's additional linters on top.
+extend-select = [
   "E", # pycodestyle
   "F", # pyflakes
   "I", # isort
@@ -237,6 +240,30 @@ convention = "numpy"
 
 [tool.ruff.lint.per-file-ignores]
 "*/__init__.py" = ["F401"]
+# The Sphinx conf idiom: `exec` the package's `__about__.py` to read
+# version metadata without importing the package (and its dependencies)
+# into the docs build. The path is a repo-local file, not user input.
+"docs/conf.py" = ["S102"]
+# Boundary catch-alls. Every `except Exception` in these files converts
+# an arbitrary failure into a reported result or a debug log instead of
+# letting it escape a place that cannot report it:
+#   middleware.py     the MCP error boundary, renders any tool exception
+#                     as an `is_error` result
+#   batch_tools.py    isolates one failed operation from its batch
+#   pane_tools/io.py  same, per send_keys operation
+#   server.py         best-effort buffer GC during lifespan shutdown
+#   server_tools.py   best-effort tmux metadata probes over sockets that
+#                     may be stale, denied, or running an old tmux
+#   mcp_swap.py       restores a CLI config's original bytes when a
+#                     write fails
+# tmux and the CLI configs fail in more ways than a narrowed clause can
+# enumerate, so narrowing here trades a logged degradation for a crash.
+"scripts/mcp_swap.py" = ["BLE001"]
+"src/libtmux_mcp/middleware.py" = ["BLE001"]
+"src/libtmux_mcp/server.py" = ["BLE001"]
+"src/libtmux_mcp/tools/batch_tools.py" = ["BLE001"]
+"src/libtmux_mcp/tools/pane_tools/io.py" = ["BLE001"]
+"src/libtmux_mcp/tools/server_tools.py" = ["BLE001"]
 
 [tool.pytest.ini_options]
 addopts = [

scripts/mcp_swap.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+#!/usr/bin/env -S uv run --script
 # /// script
 # requires-python = ">=3.10"
 # dependencies = ["tomlkit>=0.13"]
@@ -648,7 +648,7 @@ def resolve_repo_meta(repo: pathlib.Path) -> tuple[str, str]:
         msg = f"{pyproject} has no [project] table"
         raise RuntimeError(msg)
     name = str(project["name"])
-    server = name[: -len("-mcp")] if name.endswith("-mcp") else name
+    server = name.removesuffix("-mcp")
     scripts = project.get("scripts") or {}
     if not scripts:
         msg = f"{pyproject} has no [project.scripts] — cannot derive entry"
@@ -1187,7 +1187,7 @@ def _naming_hint(repo: pathlib.Path, server: str) -> str | None:
                 names.add(name)
     if server_points or not names:
         return None
-    pick = sorted(names)[0]
+    pick = min(names)
     return (
         f"note: nothing is registered under server {server!r}, but this repo is "
         f"registered as {sorted(names)} — pass --server {pick} to target it"
@@ -1237,7 +1237,7 @@ def cmd_doctor(args: argparse.Namespace) -> int:
         print("    (no CLI currently points at this repo)")
 
     if all_repo_names and server not in all_repo_names:
-        pick = sorted(all_repo_names)[0]
+        pick = min(all_repo_names)
         print(
             f"  ! server name mismatch: this repo is registered as "
             f"{sorted(all_repo_names)}, not {server!r} — use --server {pick}"

src/libtmux_mcp/server.py

@@ -128,16 +128,14 @@
     "clipboard history."
 )
 
-_BASE_INSTRUCTIONS = "\n\n".join(
-    (
-        _INSTR_HIERARCHY,
-        _INSTR_SCOPE,
-        _INSTR_METADATA_VS_CONTENT,
-        _INSTR_READ_TOOLS,
-        _INSTR_WAIT_NOT_POLL,
-        _INSTR_HOOKS_GAP,
-        _INSTR_BUFFERS_GAP,
-    )
+_BASE_INSTRUCTIONS = (
+    f"{_INSTR_HIERARCHY}\n\n"
+    f"{_INSTR_SCOPE}\n\n"
+    f"{_INSTR_METADATA_VS_CONTENT}\n\n"
+    f"{_INSTR_READ_TOOLS}\n\n"
+    f"{_INSTR_WAIT_NOT_POLL}\n\n"
+    f"{_INSTR_HOOKS_GAP}\n\n"
+    f"{_INSTR_BUFFERS_GAP}"
 )
 
 _INSTRUCTIONS_MAX_BYTES = 2048

tests/test_pane_tools.py

@@ -980,10 +980,14 @@ class FilterCurrentSyncLineFixture(t.NamedTuple):
         "current_wrapped_long_marker",
         [
             "RUN_OK",
-            "∙ }; __libtmux_mcp_status=$?; tmux set-option -p "
-            f"@libtmux_mcp_status_{_CURRENT_ID[:10]}",
-            f'{_CURRENT_ID[10:]} "$__libtmux_mcp_status"; '
-            "tmux wait-for -S libtmux_mcp_run_",
+            (
+                "∙ }; __libtmux_mcp_status=$?; tmux set-option -p "
+                f"@libtmux_mcp_status_{_CURRENT_ID[:10]}"
+            ),
+            (
+                f'{_CURRENT_ID[10:]} "$__libtmux_mcp_status"; '
+                "tmux wait-for -S libtmux_mcp_run_"
+            ),
             _CURRENT_ID,
         ],
         f"libtmux_mcp_run_{_CURRENT_ID}",
@@ -993,10 +997,14 @@ class FilterCurrentSyncLineFixture(t.NamedTuple):
         "previous_wrapped_long_marker",
         [
             "RUN_OK",
-            "∙ }; __libtmux_mcp_status=$?; tmux set-option -p "
-            f"@libtmux_mcp_status_{_PREVIOUS_ID[:10]}",
-            f'{_PREVIOUS_ID[10:]} "$__libtmux_mcp_status"; '
-            "tmux wait-for -S libtmux_mcp_run_",
+            (
+                "∙ }; __libtmux_mcp_status=$?; tmux set-option -p "
+                f"@libtmux_mcp_status_{_PREVIOUS_ID[:10]}"
+            ),
+            (
+                f'{_PREVIOUS_ID[10:]} "$__libtmux_mcp_status"; '
+                "tmux wait-for -S libtmux_mcp_run_"
+            ),
             _PREVIOUS_ID,
         ],
         f"libtmux_mcp_run_{_CURRENT_ID}",
@@ -1006,8 +1014,10 @@ class FilterCurrentSyncLineFixture(t.NamedTuple):
         "current_short_marker",
         [
             "RUN_OK",
-            f'∙ }}; s=$?; tmux set-option -p @s_{_SHORT_CURRENT_ID} "$s"; '
-            f"tmux wait-for -S r_{_SHORT_CURRENT_ID}",
+            (
+                f'∙ }}; s=$?; tmux set-option -p @s_{_SHORT_CURRENT_ID} "$s"; '
+                f"tmux wait-for -S r_{_SHORT_CURRENT_ID}"
+            ),
         ],
         f"r_{_SHORT_CURRENT_ID}",
         f"@s_{_SHORT_CURRENT_ID}",

tests/test_prompts.py

@@ -438,7 +438,7 @@ async def _render() -> str:
     block = re.search(
         r'\*\*Sample render\*\* \(``pane_id="%1"``\):\n\n````markdown\n(.*?)````',
         page.read_text(),
-        re.S,
+        re.DOTALL,
     )
     assert block is not None, "interrupt_gracefully sample-render block not found"