refactor: Do config file existence check in Config.read()

sphinx/application.py

@@ -152,12 +152,6 @@ class Sphinx:
         self.srcdir = abspath(srcdir)
         self.outdir = abspath(outdir)
         self.doctreedir = abspath(doctreedir)
-        self.confdir = confdir
-        if self.confdir:  # confdir is optional
-            self.confdir = abspath(self.confdir)
-            if not path.isfile(path.join(self.confdir, 'conf.py')):
-                raise ApplicationError(__("config directory doesn't contain a "
-                                          "conf.py file (%s)") % confdir)
 
         if not path.isdir(self.srcdir):
             raise ApplicationError(__('Cannot find source directory (%s)') %
@@ -212,9 +206,13 @@ class Sphinx:
 
         # read config
         self.tags = Tags(tags)
-        if self.confdir is None:
+        if confdir is None:
+            # set confdir to srcdir if -C given (!= no confdir); a few pieces
+            # of code expect a confdir to be set
+            self.confdir = self.srcdir
             self.config = Config({}, confoverrides or {})
         else:
+            self.confdir = abspath(confdir)
             self.config = Config.read(self.confdir, confoverrides or {}, self.tags)
 
         # initialize some limited config variables before initialize i18n and loading
@@ -230,11 +228,6 @@ class Sphinx:
                 __('This project needs at least Sphinx v%s and therefore cannot '
                    'be built with this version.') % self.config.needs_sphinx)
 
-        # set confdir to srcdir if -C given (!= no confdir); a few pieces
-        # of code expect a confdir to be set
-        if self.confdir is None:
-            self.confdir = self.srcdir
-
         # load all built-in extension modules
         for extension in builtin_extensions:
             self.setup_extension(extension)

sphinx/config.py

@@ -166,6 +166,9 @@ class Config:
     def read(cls, confdir: str, overrides: Dict = None, tags: Tags = None) -> "Config":
         """Create a Config object from configuration file."""
         filename = path.join(confdir, CONFIG_FILENAME)
+        if not path.isfile(filename):
+            raise ConfigError(__("config directory doesn't contain a conf.py file (%s)") %
+                              confdir)
         namespace = eval_config_file(filename, tags)
         return cls(namespace, overrides or {})
 

tests/test_config.py

@@ -74,6 +74,11 @@ def test_core_config(app, status, warning):
     assert cfg['project'] == cfg.project == 'Sphinx Tests'
 
 
+def test_config_not_found(tempdir):
+    with pytest.raises(ConfigError):
+        Config.read(tempdir)
+
+
 def test_extension_values():
     config = Config()