Give better error message if YAML config is bad

4 files changed, 27 insertions, 1 deletions

diff --git a/cliapp/__init__.py b/cliapp/__init__.py
index 77aae09..4b0cede 100644
--- a/cliapp/__init__.py
+++ b/cliapp/__init__.py
@@ -34,7 +34,8 @@ from .util import MemoryProfileDumper
 from .fmt import TextFormat
 from .app import Application, AppException
 from .settings import (Settings, log_group_name, config_group_name,
-                       perf_group_name, UnknownConfigVariable)
+                       perf_group_name, UnknownConfigVariable,
+                       MalformedYamlConfig)
 from .runcmd import runcmd, runcmd_unchecked, shell_quote, ssh_runcmd
 
 # The plugin system
diff --git a/cliapp/app.py b/cliapp/app.py
index 1aa35cb..cd1b576 100644
--- a/cliapp/app.py
+++ b/cliapp/app.py
@@ -192,6 +192,9 @@ class Application(object):
         except cliapp.UnknownConfigVariable, e:  # pragma: no cover
             stderr.write('ERROR: %s\n' % str(e))
             sys.exit(1)
+        except cliapp.MalformedYamlConfig as e:  # pragma: no cover
+            stderr.write('ERROR: %s\n' % str(e))
+            sys.exit(1)
         except AppException, e:
             log(traceback.format_exc())
             stderr.write('ERROR: %s\n' % str(e))
diff --git a/cliapp/settings.py b/cliapp/settings.py
index 1a88a6b..1fe1a67 100644
--- a/cliapp/settings.py
+++ b/cliapp/settings.py
@@ -48,6 +48,15 @@ class UnknownConfigVariable(cliapp.AppException):
         return self.msg
 
 
+class MalformedYamlConfig(cliapp.AppException):  # pragma: no cover
+
+    def __init__(self, msg):
+        cliapp.AppException.__init__(self, msg)
+
+    def __str__(self):  # pragma: no cover
+        return self.msg
+
+
 class Setting(object):
 
     action = 'store'
@@ -810,6 +819,7 @@ class Settings(object):
 
     def _read_yaml(self, pathname, f):
         obj = yaml.safe_load(f)
+        self._check_yaml(pathname, obj)
         config = obj.get('config', {})
         for name, value in config.items():
             if name not in self._settingses:
@@ -826,6 +836,17 @@ class Settings(object):
             for option in obj[section]:
                 section_data[option] = obj[section][option]
 
+    def _check_yaml(self, pathname, obj):  # pragma: no cover
+        if not isinstance(obj, dict):
+            raise cliapp.MalformedYamlConfig(
+                'Configuration file %s does not specify a key/value mapping' %
+                pathname)
+
+        if 'config' not in obj:
+            raise cliapp.MalformedYamlConfig(
+                'Configuration file %s does not have a "config" key' %
+                pathname)
+
     def _generate_manpage(self, o, dummy, value, p):  # pragma: no cover
         template = open(value).read()
         generator = ManpageGenerator(template, p, self._arg_synopsis,
diff --git a/cliapp/settings_tests.py b/cliapp/settings_tests.py
index efb7db3..9360b63 100644
--- a/cliapp/settings_tests.py
+++ b/cliapp/settings_tests.py
@@ -482,6 +482,7 @@ something = else
 
         def mock_open(filename, mode=None):
             return StringIO.StringIO('''\
+config: {}
 extra:
   something: else
 ''')