Fix coverage.

README.md

@@ -11,6 +11,7 @@ Bi-directional version.cfg <–> requirements.txt synchronization
 
 - [Installation](#installation)
 - [Constraints](#constraints)
+- [Hacking](#hacking)
 - [License](#license)
 
 ## Installation
@@ -25,6 +26,14 @@ pip install vereqsyn
 * So `version.cfg` can contain comments, the ones in `requirements.txt` are
   lost when running recreate.
 
+## Hacking
+
+### Run the tests
+
+```console
+hatch run cov
+```
+
 ## License
 
 `vereqsyn` is distributed under the terms of the [MIT](https://spdx.org/licenses/MIT.html) license.

pyproject.toml

@@ -77,6 +77,8 @@ exclude_lines = [
   "if TYPE_CHECKING:",
 ]
 skip_covered = true
+show_missing = true
+fail_under = 100
 
 [tool.ruff]
 # N802: Function name {name} should be lowercase

tests/test_vereqsyn.py

@@ -3,7 +3,7 @@
 
 import pytest
 
-from vereqsyn import VersionCfgRequirementsTxtSync
+from vereqsyn import VersionCfgRequirementsTxtSync, ConfigFile
 
 
 @pytest.fixture(scope="session")
@@ -85,3 +85,10 @@ def test_VersionCfg_RequirementsTxt_Sync__update__2(fixtures, tmp_path):
     assert not component.in_sync()
     component.update()
     assert component.in_sync()
+
+def test_ConfigFile____post_init____1():
+    """It raises a ValueError, if the given file does not exist."""
+    with pytest.raises(ValueError) as e:
+        ConfigFile(pathlib.Path('i-do-not-exist.cfg'))
+    assert e.match("PosixPath\('i-do-not-exist.cfg'\) does not exist\.")
+