test: disable coverage for cli test

It does not really provide much value there and seems to have quite some
impact, removing this reduces the running time of this test from ~10s
(out of a total of ~25s) to ~1s (when run with tox).

src/fava/cli.py

@@ -18,7 +18,7 @@
 
 
 class AddressInUse(click.ClickException):  # noqa: D101
-    def __init__(self, port: int) -> None:
+    def __init__(self, port: int) -> None:  # pragma: no cover
         super().__init__(
             f"Cannot start Fava because port {port} is already in use."
             "\nPlease choose a different port with the '-p' option.",
@@ -33,7 +33,7 @@ def __init__(self, path: str) -> None:
 
 
 class NoFileSpecifiedError(click.UsageError):  # noqa: D101
-    def __init__(self) -> None:
+    def __init__(self) -> None:  # pragma: no cover
         super().__init__("No file specified")
 
 

tests/test_cli.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
+import os
 import sys
+from pathlib import Path
 from socket import socket
 from subprocess import PIPE
 from subprocess import Popen
@@ -11,11 +13,35 @@
 
 import pytest
 
+from fava.cli import _add_env_filenames
+from fava.cli import NonAbsolutePathError
+
 if TYPE_CHECKING:  # pragma: no cover
-    from pathlib import Path
     from typing import IO
 
 
+def test__add_env_filenames(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    absolute_path = Path.cwd().resolve()
+    absolute = str(absolute_path)
+    asdf = str(absolute_path / "asdf")
+    other = str(absolute_path / "other")
+
+    monkeypatch.delenv("BEANCOUNT_FILE", raising=False)
+    assert _add_env_filenames((asdf,)) == {asdf}
+
+    monkeypatch.setenv("BEANCOUNT_FILE", "path")
+    with pytest.raises(NonAbsolutePathError):
+        _add_env_filenames((asdf,))
+
+    monkeypatch.setenv("BEANCOUNT_FILE", absolute)
+    assert _add_env_filenames((asdf,)) == {absolute, asdf}
+
+    monkeypatch.setenv("BEANCOUNT_FILE", os.pathsep.join([absolute, other]))
+    assert _add_env_filenames((asdf,)) == {absolute, other, asdf}
+
+
 @pytest.fixture()
 def open_port() -> int:
     """Get an open port."""
@@ -40,6 +66,7 @@ def output_contains(stdout: IO[str], output: str) -> bool:
 
 
 @pytest.mark.skipif(sys.platform == "win32", reason="does not run on windows")
+@pytest.mark.no_cover()
 def test_cli(
     monkeypatch: pytest.MonkeyPatch,
     test_data_dir: Path,