.ruff.toml

# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2026)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# In addition to the standard set of exclusions, omit all tests:
extend-exclude = [
  # Autogenerated files:
  "lib/streamlit/proto",
  "lib/streamlit/emojis.py",
  "lib/streamlit/material_icon_names.py",
  # File with an expected compilation error:
  "e2e_playwright/compilation_error_dialog.py",
  # Ignore frontend directory:
  "frontend/**",
]

target-version = 'py310'
line-length = 88

[format]
docstring-code-format = true
docstring-code-line-length = "dynamic"
line-ending = "lf"

[lint]
preview = true
explicit-preview-rules = false
# We activate all rules and only ignore the rules that we don't want to enforce
# or that are not relevant for our codebase.
select = ["ALL"]
ignore = [
  # Rules planned to be supported in the future:
  "EM101",  # Checks for the use of string literals in exception constructors.
  "EM102",  # Checks for the use of f-strings in exception constructors.
  "TRY003", # Checks for exception messages that are not defined in the exception class itself.
  # Ignored rule sets:
  "DTZ", # Checks for usage of unsafe naive datetime class.
  "PTH", # Enforces usage of pathlib.
  "C90", # Checks for McCabe complexity.
  "FBT", # Forbids boolean positional arguments.
  "SLF", # Checks unexpected for private member access.
  "BLE", # Checks for blind except statements.
  "CPY", # Checks for copyright statement.
  "DOC", # Checks for correct docstring format.
  # Ignored rules:
  "A002",    # Checks if function argument shadows a Python builtin.
  "ANN401",  # Checks that `any` is not used as an annotation.
  "B904",    # Checks for raise statements in exception handlers that lack a from clause.
  "COM812",  # Checks for absence of trailing commas. Not recommended with formatter.
  "COM819",  # Checks for presence of prohibited trailing commas. Not recommended with formatter.
  "D100",    # Checks for missing docstring in public module.
  "D101",    # Checks for missing docstring in public class.
  "D102",    # Checks for missing docstring in public method.
  "D103",    # Checks for missing docstring in public function.
  "D104",    # Checks for missing docstring in public package.
  "D105",    # Checks for missing docstring in magic method.
  "D106",    # Checks for missing docstring in public nested class.
  "D107",    # Checks for missing docstring in __init__.
  "D202",    # Checks for no-blank line after docstring.
  "D205",    # Checks for missing blank line after docstring summary.
  "D401",    # Checks for docstring to start with imperative mood.
  "E266",    # Checks for multiple leading hashes in block comments.
  "FIX002",  # Checks todo comments (which we want to allow).
  "FURB101", # Checks for open and read calls that can be replaced by pathlib.
  "FURB103", # Checks for open and write calls that can be replaced by pathlib.
  "FURB113", # Checks for repeated append calls that can be replaced by extend.
  "FURB152", # Checks for math constants that could use math module.
  "PD009",   # Checks for usage of pd.DataFrame.iat.
  "PGH003",  # Checks for blanket type ignore.
  "PLC0415", # Enforces imports to be at the top-level of the file.
  "PLC1901", # Checks for comparisons to empty string.
  "PLC2701", # Checks for imports of private names.
  "PLR0904", # Checks for classes with too many public methods.
  "PLR0911", # Checks for functions with too many return statements.
  "PLR0912", # Checks for functions with too many branches.
  "PLR0913", # Checks for functions with too many arguments.
  "PLR0914", # Checks for functions with too many local variables.
  "PLR0915", # Checks for functions with too many statements.
  "PLR0916", # Checks for too many boolean expressions in if statements.
  "PLR0917", # Checks for functions with too many positional arguments.
  "PLR1702", # Checks for functions with too many nested blocks.
  "PLR2004", # Checks for numerical values that could be put into a constant.
  "PLR6301", # Checks for methods that do not use self.
  "PLW0108", # Checks for lambdas that can be replaced by existing functions.
  "PLW3201", # Checks for bad dunder method names.
  "PT012",   # Checks for pytest.raises context managers with multiple statements.
  "PT019",   # Checks for tests that should use @pytest.mark.usefixtures (incompatible with unittest.patch)
  "PYI041",  # Checks for parameter annotations that contain redundant unions between builtin numeric types (e.g., int | float).
  "PYI051",  # Checks for redundant unions between a Literal and a builtin supertype of that Literal.
  "RET504",  # Checks for assignments that immediately precede a return of the assigned variable (too opinionated).
  "RSE102",  # Checks for unnecessary parentheses on raised exceptions.
  "RUF052",  # Checks for dummy variables that are used.
  "RUF067",  # Checks for non empty __init__ modules.
  "SIM105",  # Enforces use of contextlib.suppress.
  "SIM108",  # Enforces ternary operators instead of if-else.
  "SIM115",  # Enforces context manager for opening files.
  "SIM117",  # Enforces single with statement with multiple contexts.
  "SIM905",  # Enforces list instead of st.split.
  "TD002",   # Checks for missing author in TODO comment.
  "TD003",   # Checks for missing issue link in TODO comment.
  "TRY300",  # Checks for return statements in try blocks.
]
exclude = [
  # pympler is a vendored dependency that doesn't conform to our linting rules:
  "lib/streamlit/vendor/**",
]
extend-safe-fixes = ["TC002", "TC003"]

[lint.per-file-ignores]
# Only add ignores for entire folders here. To ignore rules in individual
# files, use the noqa ignore comment on top of the given file.
"e2e_playwright/**" = [
  "B018",   # Allow useless expressions (e.g., for side effects in tests).
  "N999",   # Allow invalid module names (test files use descriptive names).
  "NPY002", # Allow legacy numpy random generation.
  "PD",     # Ignore pandas-vet rules (test data manipulation patterns).
  "PERF",   # Ignore performance rules (clarity over speed in tests).
  "RUF029", # Allow async functions without await (intentional for testing async behavior).
  "S",      # Ignore bandit security rules (test code doesn't need security hardening).
  "T20",    # Allow print statements (useful for test debugging).
  "TRY",    # Ignore tryceratops rules (simpler exception handling in tests).
]
"lib/tests/**" = [
  "ANN",     # Ignore annotation rules (test functions don't need full typing).
  "ARG",     # Allow unused arguments (common in test fixtures and mocks).
  "D",       # Ignore docstring rules (tests are self-documenting via names).
  "FURB118", # Allow all operators (tests may use operator module intentionally).
  "FURB189", # Allow subclassing of builtin types (for test mocking).
  "INP",     # Allow implicit namespace packages (test directories).
  "N",       # Ignore naming conventions (test names can be descriptive/long).
  "NPY002",  # Allow legacy numpy random generation.
  "PD",      # Ignore pandas-vet rules (test data manipulation patterns).
  "PERF",    # Ignore performance rules (clarity over speed in tests).
  "PLC2801", # Allow dunder calls (e.g., object.__setattr__ for frozen dataclasses).
  "RUF029",  # Allow async functions without await (test fixtures, mocks, ASGI callables).
  "S",       # Ignore bandit security rules (test code doesn't need security hardening).
  "TRY",     # Ignore tryceratops rules (simpler exception handling in tests).
]
"scripts/**" = ["T20", "INP", "PERF", "S", "TRY002"]

[lint.flake8-tidy-imports]
# Disallow all relative imports.
ban-relative-imports = "all"

[lint.isort]
known-first-party = ["streamlit", "shared", "tests", "e2e_playwright"]

[lint.pydocstyle]
convention = "numpy"

[lint.pycodestyle]
# Allow lines (e.g. comments) up to 120 characters instead of 88,
# which works well with Github.
max-line-length = 120

[lint.flake8-comprehensions]
# Allow dict calls that make use of keyword arguments (e.g., dict(a=1, b=2)).
allow-dict-calls-with-keyword-arguments = true

[lint.flake8-unused-arguments]
# Ignore unused variadic argument, like *args and **kwargs.
ignore-variadic-names = true

[lint.flake8-annotations]
# Allow missing return annotation on functions that return None:
suppress-none-returning = true