Add plain check command and refactor pre-commit to use it

Extract core validation checks (custom commands, code linting, preflight,
migrations, tests) into a new `plain check` command. Pre-commit now delegates
to `plain check` instead of duplicating the logic. Supports --skip-test for
faster iteration.

Author: davegaeddert

.claude/rules/plain.md

@@ -71,6 +71,17 @@ Examples:
 - **plain-tunnel** — Remote access to local dev server
 - **plain-vendor** — Vendor CDN scripts and styles
 
+## Checks
+
+`uv run plain check` runs core validation checks: code linting, preflight, migration state, and tests. Stops on first failure.
+
+```
+uv run plain check              # Run all checks
+uv run plain check --skip-test  # Skip tests (faster iteration)
+```
+
+`uv run plain pre-commit` wraps `plain check` with additional commit-specific steps (custom commands, uv lock, build).
+
 ## Shell
 
 `uv run plain shell` opens an interactive Python shell with Plain configured and database access.

plain-dev/plain/dev/README.md

@@ -94,14 +94,16 @@ A built-in pre-commit hook that you can install with `plain pre-commit --install
 
 Runs:
 
-- Custom commands defined in `pyproject.toml` at `tool.plain.pre-commit.run`
-- `plain code check`, if [`plain.code`](../../plain-code/plain/code/README.md) is installed
-- `uv lock --locked`, if using uv
-- `plain preflight`
-- `plain migrate --check`
-- `plain makemigrations --dry-run --check`
+- `uv lock --check`, if using uv
+- `plain check` (custom commands, code linting, preflight, migrations, tests)
 - `plain build`
-- `plain test`
+
+Custom commands can be defined in `pyproject.toml` at `tool.plain.check.run` and will run as part of `plain check`:
+
+```toml
+[tool.plain.check.run]
+my-check = {cmd = "echo 'running my check'"}
+```
 
 ## Settings
 

plain-dev/plain/dev/precommit/cli.py

@@ -1,14 +1,12 @@
+from __future__ import annotations
+
 import os
-import subprocess
-import sys
-import tomllib
-from importlib.util import find_spec
 from pathlib import Path
 
 import click
 
 from plain.cli import register_cli
-from plain.cli.print import print_event
+from plain.cli.check import check_short, run_core_checks
 from plain.cli.runtime import without_runtime_setup
 
 
@@ -46,75 +44,9 @@ def install() -> None:
 def run_checks() -> None:
     """Run all pre-commit checks"""
 
-    pyproject = Path("pyproject.toml")
-
-    if pyproject.exists():
-        with open(pyproject, "rb") as f:
-            pyproject = tomllib.load(f)
-        for name, data in (
-            pyproject.get("tool", {})
-            .get("plain", {})
-            .get("pre-commit", {})
-            .get("run", {})
-        ).items():
-            cmd = data["cmd"]
-            print_event(f"Custom: {cmd}")
-            result = subprocess.run(cmd, shell=True)
-            if result.returncode != 0:
-                sys.exit(result.returncode)
-
-    # Run this first since it's probably the most likely to fail
-    if find_spec("plain.code"):
-        check_short("plain code check", "plain", "code", "check")
-
     if Path("uv.lock").exists():
         check_short("uv lock --check", "uv", "lock", "--check")
 
-    if plain_db_connected():
-        check_short("plain preflight", "plain", "preflight", "--quiet")
-        check_short("plain migrate --check", "plain", "migrate", "--check")
-        check_short(
-            "plain makemigrations --dry-run --check",
-            "plain",
-            "makemigrations",
-            "--dry-run",
-            "--check",
-        )
-    else:
-        check_short("plain preflight", "plain", "preflight", "--quiet")
-        click.secho("--> Skipping migration checks", bold=True, fg="yellow")
+    run_core_checks(skip_test=False)
 
     check_short("plain build", "plain", "build")
-
-    if find_spec("plain.pytest"):
-        print_event("plain test")
-        result = subprocess.run(["plain", "test"])
-        if result.returncode != 0:
-            sys.exit(result.returncode)
-
-
-def plain_db_connected() -> bool:
-    result = subprocess.run(
-        [
-            "plain",
-            "migrations",
-            "list",
-        ],
-        stdout=subprocess.DEVNULL,
-        stderr=subprocess.DEVNULL,
-    )
-    return result.returncode == 0
-
-
-def check_short(message: str, *args: str) -> None:
-    print_event(message, newline=False)
-    env = {**os.environ, "FORCE_COLOR": "1"}
-    result = subprocess.run(
-        args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=env
-    )
-    if result.returncode != 0:
-        click.secho("✘", fg="red")
-        click.secho(result.stdout.decode("utf-8"))
-        sys.exit(1)
-    else:
-        click.secho("✔", fg="green")

plain/plain/agents/.claude/rules/plain.md

@@ -71,6 +71,17 @@ Examples:
 - **plain-tunnel** — Remote access to local dev server
 - **plain-vendor** — Vendor CDN scripts and styles
 
+## Checks
+
+`uv run plain check` runs core validation checks: code linting, preflight, migration state, and tests. Stops on first failure.
+
+```
+uv run plain check              # Run all checks
+uv run plain check --skip-test  # Skip tests (faster iteration)
+```
+
+`uv run plain pre-commit` wraps `plain check` with additional commit-specific steps (custom commands, uv lock, build).
+
 ## Shell
 
 `uv run plain shell` opens an interactive Python shell with Plain configured and database access.

plain/plain/cli/README.md

@@ -165,6 +165,7 @@ Plain includes several built-in commands:
 
 | Command               | Description                              |
 | --------------------- | ---------------------------------------- |
+| `plain check`         | Run core validation checks               |
 | `plain shell`         | Interactive Python shell                 |
 | `plain run <script>`  | Execute a Python script with app context |
 | `plain server`        | Production-ready WSGI server             |
@@ -179,6 +180,30 @@ Plain includes several built-in commands:
 
 Additional commands are added by installed packages (like `plain models migrate` from plain.models).
 
+### `plain check`
+
+Runs core validation checks in order, stopping on first failure:
+
+1. Custom commands (see below)
+2. `plain code check` (if `plain.code` is installed)
+3. `plain preflight --quiet`
+4. `plain migrate --check` (if DB connected)
+5. `plain makemigrations --dry-run --check` (if DB connected)
+6. `plain test` (if `plain.pytest` is installed)
+
+Use `--skip-test` to skip tests for faster iteration.
+
+#### Custom check commands
+
+Add custom commands to `plain check` by defining them in `pyproject.toml`:
+
+```toml
+[tool.plain.check.run]
+my-check = {cmd = "echo 'running my check'"}
+```
+
+Custom commands run first, before any built-in checks.
+
 ## FAQs
 
 #### How do I run commands that don't need the app to be set up?

plain/plain/cli/check.py

@@ -0,0 +1,92 @@
+from __future__ import annotations
+
+import os
+import subprocess
+import tomllib
+from importlib.util import find_spec
+from pathlib import Path
+
+import click
+
+from plain.cli.print import print_event
+from plain.cli.runtime import common_command
+
+
+def plain_db_connected() -> bool:
+    result = subprocess.run(
+        ["plain", "migrations", "list"],
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL,
+    )
+    return result.returncode == 0
+
+
+def check_short(message: str, *args: str) -> None:
+    print_event(message, newline=False)
+    env = {**os.environ, "FORCE_COLOR": "1"}
+    result = subprocess.run(
+        args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=env
+    )
+    if result.returncode != 0:
+        click.secho("✘", fg="red")
+        click.secho(result.stdout.decode("utf-8"))
+        raise SystemExit(1)
+    else:
+        click.secho("✔", fg="green")
+
+
+def run_custom_checks() -> None:
+    """Run custom checks from [tool.plain.check.run] in pyproject.toml."""
+    pyproject_path = Path("pyproject.toml")
+
+    if not pyproject_path.exists():
+        return
+
+    with open(pyproject_path, "rb") as f:
+        pyproject = tomllib.load(f)
+
+    for name, data in (
+        pyproject.get("tool", {}).get("plain", {}).get("check", {}).get("run", {})
+    ).items():
+        cmd = data["cmd"]
+        print_event(f"Custom: {cmd}")
+        result = subprocess.run(cmd, shell=True)
+        if result.returncode != 0:
+            raise SystemExit(result.returncode)
+
+
+def run_core_checks(*, skip_test: bool = False) -> None:
+    """Run core validation checks: custom, code, preflight, migrations, tests."""
+
+    run_custom_checks()
+
+    if find_spec("plain.code"):
+        check_short("plain code check", "plain", "code", "check")
+
+    if plain_db_connected():
+        check_short("plain preflight", "plain", "preflight", "--quiet")
+        check_short("plain migrate --check", "plain", "migrate", "--check")
+        check_short(
+            "plain makemigrations --dry-run --check",
+            "plain",
+            "makemigrations",
+            "--dry-run",
+            "--check",
+        )
+    else:
+        check_short("plain preflight", "plain", "preflight", "--quiet")
+        click.secho("--> Skipping migration checks", bold=True, fg="yellow")
+
+    if not skip_test and find_spec("plain.pytest"):
+        print_event("plain test")
+        result = subprocess.run(["plain", "test"])
+        if result.returncode != 0:
+            raise SystemExit(result.returncode)
+
+
+@common_command
+@click.command()
+@click.option("--skip-test", is_flag=True, help="Skip running tests")
+def check(skip_test: bool) -> None:
+    """Run core validation checks"""
+    run_core_checks(skip_test=skip_test)

plain/plain/cli/core.py

@@ -12,6 +12,7 @@
 from .agent import agent
 from .build import build
 from .changelog import changelog
+from .check import check
 from .chores import chores
 from .docs import docs
 from .formatting import PlainContext
@@ -33,6 +34,7 @@ def plain_cli() -> None:
     pass
 
 
+plain_cli.add_command(check)
 plain_cli.add_command(docs)
 plain_cli.add_command(request)
 plain_cli.add_command(agent)