Improve handling of missing config file (#770)

* Simplify and clarify existing logic

* Reindent multiline strings

* Extract write_config_file fixture

* Raise exception for missing config file

* Add changelog entry

changelog/770.bugfix.rst

@@ -0,0 +1 @@
+Improve error message for a missing config file.

tests/conftest.py

@@ -4,27 +4,40 @@
 import pytest
 
 from twine import settings
+from twine import utils
 
 
 @pytest.fixture()
-def pypirc(tmpdir):
-    return tmpdir / ".pypirc"
+def config_file(tmpdir, monkeypatch):
+    path = tmpdir / ".pypirc"
+    # Mimic common case of .pypirc in home directory
+    monkeypatch.setattr(utils, "DEFAULT_CONFIG_FILE", path)
+    return path
+
+
+@pytest.fixture
+def write_config_file(config_file):
+    def _write(config):
+        config_file.write(textwrap.dedent(config))
+        return config_file
+
+    return _write
 
 
 @pytest.fixture()
-def make_settings(pypirc):
+def make_settings(write_config_file):
     """Return a factory function for settings.Settings with defaults."""
-    default_pypirc = """
+    default_config = """
         [pypi]
         username:foo
         password:bar
     """
 
-    def _settings(pypirc_text=default_pypirc, **settings_kwargs):
-        pypirc.write(textwrap.dedent(pypirc_text))
+    def _settings(config=default_config, **settings_kwargs):
+        config_file = write_config_file(config)
 
         settings_kwargs.setdefault("sign_with", None)
-        settings_kwargs.setdefault("config_file", str(pypirc))
+        settings_kwargs.setdefault("config_file", config_file)
 
         return settings.Settings(**settings_kwargs)
 

tests/test_register.py

@@ -19,7 +19,7 @@ def register_settings(make_settings):
         repository: https://test.pypi.org/legacy
         username:foo
         password:bar
-    """
+        """
     )
 
 

tests/test_settings.py

@@ -14,8 +14,6 @@
 # limitations under the License.
 import argparse
 import logging
-import os.path
-import textwrap
 
 import pytest
 
@@ -29,22 +27,18 @@ def test_settings_takes_no_positional_arguments():
         settings.Settings("a", "b", "c")
 
 
-def test_settings_transforms_repository_config(tmpdir):
+def test_settings_transforms_repository_config(write_config_file):
     """Set repository config and defaults when .pypirc is provided."""
-    pypirc = os.path.join(str(tmpdir), ".pypirc")
-
-    with open(pypirc, "w") as fp:
-        fp.write(
-            textwrap.dedent(
-                """
-            [pypi]
-            repository: https://upload.pypi.org/legacy/
-            username:username
-            password:password
+    config_file = write_config_file(
         """
-            )
-        )
-    s = settings.Settings(config_file=pypirc)
+        [pypi]
+        repository: https://upload.pypi.org/legacy/
+        username:username
+        password:password
+        """
+    )
+
+    s = settings.Settings(config_file=config_file)
     assert s.repository_config["repository"] == "https://upload.pypi.org/legacy/"
     assert s.sign is False
     assert s.sign_with == "gpg"
@@ -72,16 +66,14 @@ def test_setup_logging(verbose, log_level):
     "verbose",
     [True, False],
 )
-def test_print_config_path_if_verbose(tmpdir, capsys, make_settings, verbose):
+def test_print_config_path_if_verbose(config_file, capsys, make_settings, verbose):
     """Print the location of the .pypirc config used by the user."""
-    pypirc = os.path.join(str(tmpdir), ".pypirc")
-
     make_settings(verbose=verbose)
 
     captured = capsys.readouterr()
 
     if verbose:
-        assert captured.out == f"Using configuration from {pypirc}\n"
+        assert captured.out == f"Using configuration from {config_file}\n"
     else:
         assert captured.out == ""
 

tests/test_upload.py

@@ -203,22 +203,22 @@ def test_exception_for_http_status(verbose, upload_settings, stub_response, caps
         assert "--verbose" in captured.out
 
 
-def test_get_config_old_format(make_settings, pypirc):
+def test_get_config_old_format(make_settings, config_file):
     try:
         make_settings(
             """
             [server-login]
             username:foo
             password:bar
-        """
+            """
         )
     except KeyError as err:
         assert all(
             text in err.args[0]
             for text in [
                 "'pypi'",
                 "--repository-url",
-                pypirc,
+                config_file,
                 "https://docs.python.org/",
             ]
         )
@@ -232,7 +232,7 @@ def test_deprecated_repo(make_settings):
             repository: https://pypi.python.org/pypi/
             username:foo
             password:bar
-        """
+            """
         )
 
         upload.upload(upload_settings, [helpers.WHEEL_FIXTURE])
@@ -257,7 +257,7 @@ def test_exception_for_redirect(make_settings):
         repository: https://test.pypi.org/legacy
         username:foo
         password:bar
-    """
+        """
     )
 
     stub_response = pretend.stub(