Add type checking to CI

.github/workflows/typecheck.yml

@@ -0,0 +1,32 @@
+name: lint
+
+on:
+  pull_request:
+    paths-ignore:
+      - '**.md'
+      - 'AUTHORS'
+
+jobs:
+  linters:
+    name: Typecheck
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out Git repository
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Set up Python
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        with:
+          python-version: '3.13'
+
+      - uses: astral-sh/setup-uv@7edac99f961f18b581bbd960d59d049f04c0002f # v6.4.1
+        with:
+          version: 'latest'
+
+      - name: Install dependencies
+        run: uv sync --all-extras
+
+      - name: Run mypy
+        run: |
+          uv run --no-sync --frozen -- python -m mypy --no-pretty --install-types .

changelog.md

@@ -1,3 +1,12 @@
+Upcoming Release (TBD)
+======================
+
+Internal
+--------
+
+* Add limited typechecking to CI.
+
+
 1.35.0 (2025/07/18)
 ======================
 

mycli/__init__.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import importlib.metadata
 
 __version__ = importlib.metadata.version("mycli")

mycli/clibuffer.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from prompt_toolkit.application import get_app
 from prompt_toolkit.enums import DEFAULT_BUFFER
 from prompt_toolkit.filters import Condition

mycli/clistyle.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import logging
 
 from prompt_toolkit.styles import Style, merge_styles

mycli/clitoolbar.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from prompt_toolkit.application import get_app
 from prompt_toolkit.enums import EditingMode
 from prompt_toolkit.key_binding.vi_state import InputMode

mycli/compat.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Platform and Python version compatibility support."""
 
 import sys

mycli/completion_refresher.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from collections import OrderedDict
 import threading
 

mycli/config.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from copy import copy
 from importlib import resources
 from io import BytesIO, TextIOWrapper

mycli/key_bindings.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import logging
 
 from prompt_toolkit.enums import EditingMode

mycli/lexer.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from pygments.lexer import inherit
 from pygments.lexers.sql import MySqlLexer
 from pygments.token import Keyword

mycli/magic.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import logging
 
 import sql.connection

mycli/main.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from collections import defaultdict, namedtuple
 import logging
 import os

mycli/packages/completion_engine.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import sqlparse
 from sqlparse.sql import Comparison, Identifier, Where
 

mycli/packages/filepaths.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import os
 import platform
 

mycli/packages/hybrid_redirection.py

@@ -5,8 +5,8 @@
 
 import sqlglot
 
-from mycli.compat import WIN
-from mycli.packages.special.delimitercommand import DelimiterCommand
+from mycli.compat import WIN  # type: ignore[attr-defined]
+from mycli.packages.special.delimitercommand import DelimiterCommand  # type: ignore[attr-defined]
 
 logger = logging.getLogger(__name__)
 delimiter_command = DelimiterCommand()

mycli/packages/paramiko_stub/__init__.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """A module to import instead of paramiko when it is not available (to avoid
 checking for paramiko all over the place).
 

mycli/packages/parseutils.py

@@ -1,9 +1,11 @@
+# type: ignore
+
 import re
 
 import sqlglot
-import sqlparse
-from sqlparse.sql import Function, Identifier, IdentifierList
-from sqlparse.tokens import DML, Keyword, Punctuation
+import sqlparse  # type: ignore[import-untyped]
+from sqlparse.sql import Function, Identifier, IdentifierList  # type: ignore[import-untyped]
+from sqlparse.tokens import DML, Keyword, Punctuation  # type: ignore[import-untyped]
 
 cleanup_regex = {
     # This matches only alphanumerics and underscores.

mycli/packages/prompt_utils.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import sys
 
 import click

mycli/packages/special/__init__.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 __all__ = []
 
 

mycli/packages/special/dbcommands.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import logging
 import os
 import platform

mycli/packages/special/delimitercommand.py

@@ -1,6 +1,8 @@
+# type: ignore
+
 import re
 
-import sqlparse
+import sqlparse  # type: ignore[import-untyped]
 
 
 class DelimiterCommand(object):

mycli/packages/special/favoritequeries.py

@@ -1,3 +1,6 @@
+# type: ignore
+
+
 class FavoriteQueries(object):
     section_name = "favorite_queries"
 

mycli/packages/special/iocommands.py

@@ -1,14 +1,17 @@
+# type: ignore
+
 import locale
 import logging
 import os
 import re
 import shlex
 import subprocess
 from time import sleep
+from typing import Any
 
 import click
-import pyperclip
-import sqlparse
+import pyperclip  # type: ignore[import-untyped]
+import sqlparse  # type: ignore[import-untyped]
 
 from mycli.compat import WIN
 from mycli.packages.prompt_utils import confirm_destructive_query
@@ -25,7 +28,7 @@
 tee_file = None
 once_file = None
 written_to_once_file = False
-PIPE_ONCE = {
+PIPE_ONCE: dict[str, Any] = {
     'process': None,
     'stdin': [],
     'stdout_file': None,

mycli/packages/special/main.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from collections import namedtuple
 import logging
 

mycli/packages/special/utils.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import os
 import subprocess
 

mycli/packages/tabular_output/sql_format.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Format adapter for sql."""
 
 from mycli.packages.parseutils import extract_tables_from_complete_statements

mycli/packages/toolkit/fzf.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import re
 from shutil import which
 

mycli/packages/toolkit/history.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import os
 from typing import List, Tuple, Union
 

mycli/shortcuts.py

@@ -1,3 +1,6 @@
+# type: ignore
+
+
 def server_date(sqlexecute, quoted: bool = False) -> str:
     server_date_str = sqlexecute.now().strftime('%Y-%m-%d')
     if quoted:

mycli/sqlcompleter.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from collections import Counter
 import logging
 import re

mycli/sqlexecute.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import enum
 import logging
 import re

pyproject.toml

@@ -39,6 +39,7 @@ ssh = ["paramiko", "sshtunnel"]
 dev = [
     "behave>=1.2.6",
     "coverage>=7.2.7",
+    "mypy>=1.16.1",
     "pexpect>=4.9.0",
     "pytest>=7.4.4",
     "pytest-cov>=4.1.0",
@@ -99,3 +100,17 @@ exclude = [
     'build',
     'mycli_dev',
 ]
+
+[tool.mypy]
+pretty                 = true
+strict_equality        = true
+ignore_missing_imports = true
+warn_unreachable       = true
+warn_redundant_casts   = true
+warn_no_return         = true
+warn_unused_configs    = true
+show_column_numbers    = true
+exclude = [
+    '^build/',
+    '^dist/',
+]

test/conftest.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import pytest
 
 import mycli.sqlexecute

test/features/db_utils.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import pymysql
 
 

test/features/environment.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import os
 import shutil
 import sys

test/features/fixture_utils.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import os
 
 

test/features/steps/auto_vertical.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 from textwrap import dedent
 
 from behave import then, when

test/features/steps/basic_commands.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Steps for behavioral style tests are defined in this module.
 
 Each step is defined by the string decorating it. This string is used

test/features/steps/connection.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import io
 import os
 

test/features/steps/crud_database.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Steps for behavioral style tests are defined in this module.
 
 Each step is defined by the string decorating it. This string is used

test/features/steps/crud_table.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Steps for behavioral style tests are defined in this module.
 
 Each step is defined by the string decorating it. This string is used

test/features/steps/iocommands.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import os
 from textwrap import dedent
 

test/features/steps/named_queries.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Steps for behavioral style tests are defined in this module.
 
 Each step is defined by the string decorating it. This string is used

test/features/steps/specials.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Steps for behavioral style tests are defined in this module.
 
 Each step is defined by the string decorating it. This string is used

test/features/steps/utils.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import shlex
 
 

test/features/steps/wrappers.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 import re
 import sys
 import textwrap

test/features/wrappager.py

@@ -1,8 +1,9 @@
 #!/usr/bin/env python
+
 import sys
 
 
-def wrappager(boundary):
+def wrappager(boundary: str) -> None:
     print(boundary)
     while 1:
         buf = sys.stdin.read(2048)

test/test_clistyle.py

@@ -1,3 +1,5 @@
+# type: ignore
+
 """Test the mycli.clistyle module."""
 
 from pygments.style import Style