Merge pull request #88 from MarcoGorelli/type-checking

CI Type checking

.pre-commit-config.yaml

@@ -19,3 +19,7 @@ repos:
     rev: 5.0.9
     hooks:
     -   id: isort
+-   repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v0.782
+    hooks:
+    -   id: mypy

README.rst

@@ -23,6 +23,9 @@ nbQA
 .. image:: https://img.shields.io/badge/pre--commit-enabled-brightgreen?logo=pre-commit&logoColor=white
     :target: https://github.com/pre-commit/pre-commit
 
+.. image:: http://www.mypy-lang.org/static/mypy_badge.svg
+    :target: http://mypy-lang.org/
+
 Adapter to run any code-quality tool on a Jupyter notebook. Documentation is hosted here_.
 
 Prerequisites

azure-pipelines.yml

@@ -34,6 +34,7 @@ stages:
           black . --check
           isort . --check-only
           flake8
+          mypy .
         displayName: 'static analysis'
 
       - script: |

mypy.ini

@@ -0,0 +1,16 @@
+[mypy]
+disallow_untyped_defs = True
+
+# 3rd party libraries
+[mypy-pytest]
+ignore_missing_imports = True
+[mypy-_pytest.capture]
+ignore_missing_imports = True
+[mypy-setuptools]
+ignore_missing_imports = True
+
+# non-nbqa files
+[mypy-setup]
+ignore_errors = True
+[mypy-conf]
+ignore_errors = True

nbqa/__main__.py

@@ -6,7 +6,7 @@
 import sys
 import tempfile
 from pathlib import Path
-from typing import List
+from typing import Dict, Iterator, List, Optional, Tuple
 
 from nbqa import (
     __version__,
@@ -17,7 +17,7 @@
 )
 
 
-def _parse_args(raw_args):
+def _parse_args(raw_args: Optional[List[str]]) -> Tuple[str, str, List[str]]:
     """
     Parse command-line arguments.
     """
@@ -46,7 +46,7 @@ def _parse_args(raw_args):
     return command, root_dir, kwargs
 
 
-def _get_notebooks(root_dir) -> List[Path]:
+def _get_notebooks(root_dir: str) -> Iterator[Path]:
     """
     Get generator with all notebooks in directory.
     """
@@ -55,7 +55,7 @@ def _get_notebooks(root_dir) -> List[Path]:
     return (i for i in Path(".").rglob("*.ipynb") if ".ipynb_checkpoints" not in str(i))
 
 
-def _temp_python_file_for_notebook(notebook, tmpdir):
+def _temp_python_file_for_notebook(notebook: Path, tmpdir: str) -> Path:
     """
     Get temporary file to save converted notebook into.
     """
@@ -70,7 +70,9 @@ def _temp_python_file_for_notebook(notebook, tmpdir):
     return temp_python_file
 
 
-def _replace_full_path_out_err(out, err, temp_python_file, notebook):
+def _replace_full_path_out_err(
+    out: str, err: str, temp_python_file: Path, notebook: Path
+) -> Tuple[str, str]:
     """
     Take care of case when out/err display full path.
     """
@@ -85,7 +87,9 @@ def _replace_full_path_out_err(out, err, temp_python_file, notebook):
     return out, err
 
 
-def _replace_relative_path_out_err(out, err, notebook):
+def _replace_relative_path_out_err(
+    out: str, err: str, notebook: Path
+) -> Tuple[str, str]:
     """
     Take care of case when out/err display relative path.
 
@@ -109,7 +113,9 @@ def _replace_relative_path_out_err(out, err, notebook):
     return out, err
 
 
-def _map_python_line_to_nb_lines(out, err, temp_python_file, notebook):
+def _map_python_line_to_nb_lines(
+    out: str, err: str, temp_python_file: Path, notebook: Path
+) -> Tuple[str, str]:
     """
     Make sure stdout and stderr make reference to Jupyter Notebook lines.
     """
@@ -123,6 +129,7 @@ def _map_python_line_to_nb_lines(out, err, temp_python_file, notebook):
             cell_no += 1
             cell_count = 0
         else:
+            assert cell_count is not None
             cell_count += 1
         mapping[n + 1] = f"cell_{cell_no}:{cell_count}"
     out = re.sub(
@@ -135,8 +142,8 @@ def _map_python_line_to_nb_lines(out, err, temp_python_file, notebook):
 
 
 def _replace_temp_python_file_references_in_out_err(
-    temp_python_file, notebook, out, err
-):
+    temp_python_file: Path, notebook: Path, out: str, err: str
+) -> Tuple[str, str]:
     """
     Replace references to temporary directory name with current working directory.
     """
@@ -146,17 +153,18 @@ def _replace_temp_python_file_references_in_out_err(
     return out, err
 
 
-def _replace_tmpdir_references(out, err, tmpdirname, cwd=None):
+def _replace_tmpdir_references(
+    out: str, err: str, cwd: Optional[Path] = None
+) -> Tuple[str, str]:
     """
     Replace references to temporary directory name with current working directory.
 
     Examples
     --------
     >>> out = f"rootdir: {os.path.join('tmp', 'tmpdir')}\\n"
     >>> err = ""
-    >>> tmpdirname = os.path.join('tmp', 'tmpdir')
     >>> cwd = Path("nbQA-dev")
-    >>> out, err = _replace_tmpdir_references(out, err, tmpdirname, cwd)
+    >>> out, err = _replace_tmpdir_references(out, err, cwd)
     >>> out.strip(os.linesep)
     'rootdir: nbQA-dev'
     """
@@ -181,7 +189,7 @@ def _replace_tmpdir_references(out, err, tmpdirname, cwd=None):
     return new_out, new_err
 
 
-def _create_blank_init_files(notebook, tmpdirname):
+def _create_blank_init_files(notebook: Path, tmpdirname: str) -> None:
     """
     Replicate local (possibly blank) __init__ files to temporary directory.
     """
@@ -192,7 +200,7 @@ def _create_blank_init_files(notebook, tmpdirname):
         Path(tmpdirname).joinpath(i).touch()
 
 
-def _ensure_cell_separators_remain(temp_python_file):
+def _ensure_cell_separators_remain(temp_python_file: Path) -> None:
     """
     Isort removes a blank line which separates the cells.
     """
@@ -203,7 +211,9 @@ def _ensure_cell_separators_remain(temp_python_file):
         handle.write(py_file)
 
 
-def _get_arg(root_dir, tmpdirname, nb_to_py_mapping):
+def _get_arg(
+    root_dir: str, tmpdirname: str, nb_to_py_mapping: Dict[Path, Path]
+) -> Path:
     """
     Get argument to run command against.
 
@@ -230,7 +240,13 @@ def _get_arg(root_dir, tmpdirname, nb_to_py_mapping):
     return arg
 
 
-def _run_command(command, root_dir, tmpdirname, nb_to_py_mapping, kwargs):
+def _run_command(
+    command: str,
+    root_dir: str,
+    tmpdirname: str,
+    nb_to_py_mapping: Dict[Path, Path],
+    kwargs: List[str],
+) -> Tuple[str, str, int]:
     """
     Run third-party tool against given file or directory.
     """
@@ -259,7 +275,7 @@ def _run_command(command, root_dir, tmpdirname, nb_to_py_mapping, kwargs):
     return out, err, output_code
 
 
-def main(raw_args=None):
+def main(raw_args: Optional[List[str]] = None) -> None:
 
     command, root_dir, kwargs = _parse_args(raw_args)
 
@@ -289,7 +305,7 @@ def main(raw_args=None):
             command, root_dir, tmpdirname, nb_to_py_mapping, kwargs
         )
 
-        out, err = _replace_tmpdir_references(out, err, tmpdirname)
+        out, err = _replace_tmpdir_references(out, err)
 
         for notebook, temp_python_file in nb_to_py_mapping.items():
             out, err = _replace_temp_python_file_references_in_out_err(

nbqa/put_magics_back_in.py

@@ -1,7 +1,11 @@
 import re
+from typing import TYPE_CHECKING
 
+if TYPE_CHECKING:  # pragma: nocover
+    from pathlib import Path
 
-def main(path):
+
+def main(path: "Path") -> None:
 
     with open(str(path), "r") as handle:
         file = handle.read()

nbqa/replace_magics.py

@@ -1,7 +1,11 @@
 import re
+from typing import TYPE_CHECKING
 
+if TYPE_CHECKING:  # pragma: nocover
+    from pathlib import Path
 
-def main(path):
+
+def main(path: "Path") -> None:
 
     with open(str(path), "r") as handle:
         file = handle.read()

nbqa/replace_source.py

@@ -1,9 +1,13 @@
 import json
+from typing import TYPE_CHECKING
 
+if TYPE_CHECKING:  # pragma: nocover
+    from pathlib import Path
 
-def main(python_file, notebook):
+
+def main(python_file: "Path", notebook: "Path") -> None:
     """
-    Replace `source` of original notebook.
+    Replace `source` code cells of original notebook.
     """
     with open(notebook, "r") as handle:
         notebook_json = json.load(handle)

nbqa/save_source.py

@@ -1,9 +1,13 @@
 import json
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:  # pragma: nocover
+    from pathlib import Path
 
 CODE_SEPARATOR = "\n\n# %%\n"
 
 
-def main(path, temp_file):
+def main(path: "Path", temp_file: "Path") -> None:
 
     with open(path, "r") as handle:
         notebook = json.load(handle)

tests/conftest.py

@@ -1,11 +1,15 @@
 import shutil
 from pathlib import Path
+from typing import TYPE_CHECKING, Iterator
 
 import pytest
 
+if TYPE_CHECKING:
+    from py._path.local import LocalPath
+
 
 @pytest.fixture
-def tmp_notebook_for_testing(tmpdir):
+def tmp_notebook_for_testing(tmpdir: "LocalPath") -> Iterator[Path]:
     """
     Make temporary copy of test notebook before it's operated on, then revert it.
     """
@@ -21,7 +25,7 @@ def tmp_notebook_for_testing(tmpdir):
 
 
 @pytest.fixture
-def tmp_notebook_starting_with_md(tmpdir):
+def tmp_notebook_starting_with_md(tmpdir: "LocalPath") -> Iterator[Path]:
     """
     Make temporary copy of test notebook before it's operated on, then revert it.
     """

tests/test_black.py

@@ -1,12 +1,20 @@
 import difflib
 import os
+from typing import TYPE_CHECKING
 
 import pytest
 
 from nbqa.__main__ import main
 
+if TYPE_CHECKING:
+    from pathlib import Path
 
-def test_black_works(tmp_notebook_for_testing, capsys):
+    from _pytest.capture import CaptureFixture
+
+
+def test_black_works(
+    tmp_notebook_for_testing: "Path", capsys: "CaptureFixture"
+) -> None:
     """
     Check black works. Should only reformat code cells.
     """

tests/test_create_blank_init_files.py

@@ -1,10 +1,14 @@
 import os
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 from nbqa.__main__ import _create_blank_init_files
 
+if TYPE_CHECKING:
+    from py._path.local import LocalPath
 
-def test_create_blank_init_files(tmpdir):
+
+def test_create_blank_init_files(tmpdir: "LocalPath") -> None:
     """
     Check that if a notebook is in current working directory then no init file is made.
     """

tests/test_doctest.py

@@ -1,13 +1,19 @@
 import difflib
 import os
 from pathlib import Path
+from typing import TYPE_CHECKING
 
 import pytest
 
 from nbqa.__main__ import main
 
+if TYPE_CHECKING:
+    from _pytest.capture import CaptureFixture
 
-def test_pytest_doctest_works(tmp_notebook_for_testing, capsys):
+
+def test_pytest_doctest_works(
+    tmp_notebook_for_testing: Path, capsys: "CaptureFixture"
+) -> None:
     """
     Check pytest --doctest-modules works.
     """

tests/test_flake8_works.py

@@ -1,13 +1,21 @@
 import difflib
 import os
 from textwrap import dedent
+from typing import TYPE_CHECKING
 
 import pytest
 
 from nbqa.__main__ import main
 
+if TYPE_CHECKING:
+    from pathlib import Path
 
-def test_flake8_works(tmp_notebook_for_testing, capsys):
+    from _pytest.capture import CaptureFixture
+
+
+def test_flake8_works(
+    tmp_notebook_for_testing: "Path", capsys: "CaptureFixture"
+) -> None:
     """
     Check flake8 works. Shouldn't alter the notebook content.
     """