Test write_config function

snakebids/io/config.py

@@ -1,4 +1,5 @@
 from __future__ import annotations
+import errno
 
 import json
 from pathlib import Path
@@ -28,8 +29,9 @@ def write_config(
     """
     config_file = Path(config_file)
     if (config_file.exists()) and not force_overwrite:
-        err = FileExistsError(f"'{config_file}' already exists")
-        err.filename = str(config_file)
+        err = FileExistsError(
+            errno.EEXIST, f"'{config_file}' already exists", str(config_file)
+        )
         raise err
     config_file.parent.mkdir(exist_ok=True)
 

snakebids/tests/test_yaml.py

@@ -1,16 +1,73 @@
+from __future__ import annotations
+
 from io import StringIO
 from pathlib import Path
 
+import pytest
 from hypothesis import given
 from hypothesis import strategies as st
+from pyfakefs.fake_filesystem import FakeFilesystem
+from pytest_mock import MockerFixture
+from pytest_mock.plugin import MockType
 
-from snakebids.io.yaml import get_yaml_io
+import snakebids.io.config as configio
+import snakebids.io.yaml as yamlio
+from snakebids.tests.helpers import allow_function_scoped
 
 
 @given(path=st.text(min_size=1).map(Path))
 def test_paths_formatted_as_str(path: Path):
     string = StringIO()
-    yaml = get_yaml_io()
+    yaml = yamlio.get_yaml_io()
     yaml.dump({"key": path}, string)
     string.seek(0, 0)
     assert yaml.load(string)["key"] == str(path)
+
+
+class TestWriteConfig:
+    def io_mocks(self, mocker: MockerFixture) -> dict[str, MockType]:
+        return {
+            "mopen": mocker.patch.object(configio, "open", mocker.mock_open()),
+            "jsondump": mocker.patch.object(configio.json, "dump"),
+            "mkdir": mocker.patch.object(configio.Path, "mkdir"),
+            "yamldump": mocker.patch.object(yamlio.YAML, "dump"),
+        }
+
+    @allow_function_scoped
+    @given(
+        ext=st.sampled_from([".json", ".yaml", ".yml"]),
+        path=st.text().map(Path).filter(lambda p: p != Path() and not p.exists()),
+    )
+    def test_writes_correct_format(self, ext: str, path: Path, mocker: MockerFixture):
+        mocker.stopall()
+        mocks = self.io_mocks(mocker)
+        path = path.with_suffix(ext)
+        configio.write_config(path, {})
+        if ext == ".json":
+            mocks["mopen"].assert_called_once_with(path, "w", encoding="utf-8")
+            mocks["jsondump"].assert_called_once()
+            mocks["yamldump"].assert_not_called()
+        else:
+            mocks["mopen"].assert_not_called()
+            mocks["jsondump"].assert_not_called()
+            mocks["yamldump"].assert_called_once_with({}, path)
+
+    @allow_function_scoped
+    @given(path=st.text().filter(lambda s: s not in {".", ""}))
+    def test_doesnt_overwrite_file(self, path: str, fakefs: FakeFilesystem):
+        fakefs.reset()
+        fakefs.create_file(path)
+        with pytest.raises(FileExistsError, match="already exists"):
+            configio.write_config(path, {})
+
+    @allow_function_scoped
+    @given(path=st.text().filter(lambda s: s not in {".", ""}))
+    def test_overwrites_file_if_forced(
+        self, path: str, fakefs: FakeFilesystem, mocker: MockerFixture
+    ):
+        mocker.stopall()
+        fakefs.reset()
+        fakefs.create_file(path)
+        mocks = self.io_mocks(mocker)
+        configio.write_config(path, {}, force_overwrite=True)
+        assert mocks["jsondump"].call_count ^ mocks["yamldump"].call_count

typings/pyfakefs/fake_filesystem.pyi

@@ -185,7 +185,7 @@ class FakeFilesystem:
         """Set the simulated type of operating system underlying the fake
         file system."""
         ...
-    def reset(self, total_size: int | None = ...):  # -> None:
+    def reset(self, total_size: int | None = ...) -> None:
         """Remove all file system contents and reset the root."""
         ...
     def pause(self) -> None:
@@ -352,7 +352,7 @@ class FakeFilesystem:
         times: tuple[int | float, int | float] | None = ...,
         *,
         ns: tuple[int, int] | None = ...,
-        follow_symlinks: bool = ...
+        follow_symlinks: bool = ...,
     ) -> None:
         """Change the access and modified times of a file.
 
@@ -724,15 +724,15 @@ class FakeFilesystem:
         ...
     def create_file(
         self,
-        file_path: AnyPath,
+        file_path: AnyPath[AnyStr],
         st_mode: int = ...,
         contents: AnyString = ...,
         st_size: int | None = ...,
         create_missing_dirs: bool = ...,
         apply_umask: bool = ...,
         encoding: str | None = ...,
         errors: str | None = ...,
-        side_effect: Callable | None = ...,
+        side_effect: Callable[[FakeFile], Any] | None = ...,
     ) -> FakeFile:
         """Create `file_path`, including all the parent directories along
         the way.

typings/pyfakefs/helpers.pyi

@@ -4,13 +4,12 @@ This type stub file was generated by pyright.
 
 import io
 import os
-import platform
 import sys
 from typing import Any, AnyStr, Optional, Union, overload
 
 """Helper classes use for fake file system implementation."""
 AnyString = Union[str, bytes]
-AnyPath = Union[AnyStr, "os.PathLike[str]", "os.PathLike[bytes]"]
+AnyPath = Union[AnyStr, "os.PathLike[AnyStr]"]
 IS_PYPY = ...
 IS_WIN = ...
 IN_DOCKER = ...
@@ -58,12 +57,14 @@ def is_int_type(val: Any) -> bool:
 
 def is_byte_string(val: Any) -> bool:
     """Return True if `val` is a bytes-like object, False for a unicode
-    string."""
+    string.
+    """
     ...
 
 def is_unicode_string(val: Any) -> bool:
     """Return True if `val` is a unicode string, False for a bytes-like
-    object."""
+    object.
+    """
     ...
 
 @overload
@@ -73,12 +74,14 @@ def make_string_path(dir_name: os.PathLike) -> str: ...
 def make_string_path(dir_name: AnyPath) -> AnyStr: ...
 def to_string(path: Union[AnyStr, Union[str, bytes]]) -> str:
     """Return the string representation of a byte string using the preferred
-    encoding, or the string itself if path is a str."""
+    encoding, or the string itself if path is a str.
+    """
     ...
 
 def to_bytes(path: Union[AnyStr, Union[str, bytes]]) -> bytes:
     """Return the bytes representation of a string using the preferred
-    encoding, or the byte string itself if path is a byte string."""
+    encoding, or the byte string itself if path is a byte string.
+    """
     ...
 
 def join_strings(s1: AnyStr, s2: AnyStr) -> AnyStr:
@@ -88,7 +91,8 @@ def join_strings(s1: AnyStr, s2: AnyStr) -> AnyStr:
 def real_encoding(encoding: Optional[str]) -> Optional[str]:
     """Since Python 3.10, the new function ``io.text_encoding`` returns
     "locale" as the encoding if None is defined. This will be handled
-    as no encoding in pyfakefs."""
+    as no encoding in pyfakefs.
+    """
     ...
 
 def now(): ...