Merge pull request #16 from Carreau/version-docstring

Better error message for missing docstring and version.

flit/__init__.py

@@ -53,16 +53,22 @@ def main(argv=None):
 
     if args.subcmd == 'wheel':
         from .wheel import WheelBuilder
-        WheelBuilder(args.ini_file, upload=args.upload,
+        try:
+            WheelBuilder(args.ini_file, upload=args.upload,
                      verify_metadata=args.verify_metadata).build()
+        except (common.NoDocstringError, common.NoVersionError) as e:
+            sys.exit(e.args[0])
     elif args.subcmd == 'install':
         from .install import Installer
-        Installer(args.ini_file, user=args.user, symlink=args.symlink).install()
+        try:
+            Installer(args.ini_file, user=args.user, symlink=args.symlink).install()
+        except (common.NoDocstringError, common.NoVersionError) as e:
+            sys.exit(e.args[0])
     elif args.subcmd == 'init':
         from .init import TerminalIniter
         TerminalIniter().initialise()
     else:
         sys.exit('No command specified')
 
 if __name__ == '__main__':
-    main()
+    main()

flit/common.py

@@ -28,14 +28,24 @@ def file(self):
             return self.path / '__init__.py'
         else:
             return self.path
-
+class NoDocstringError(ValueError): pass
+class NoVersionError(ValueError): pass
 
 def get_info_from_module(target):
     """Load the module/package, get its docstring and __version__
     """
     sl = SourceFileLoader(target.name, str(target.file))
     m = sl.load_module()
-    docstring_lines = m.__doc__.splitlines()
+    docstring = m.__dict__.get('__doc__', None)
+    if not docstring: 
+        raise NoDocstringError('Cannot build module without docstring. '
+                                'Please add a docstring to you module.')
+    module_version = m.__dict__.get('__version__', None)
+    if not module_version: 
+        raise NoVersionError('Cannot build module without a version string. '
+                             'Please define a `__version__="x.y.z"` in your module')
+
+    docstring_lines = docstring.splitlines()
     return {'summary': docstring_lines[0],
             'version': m.__version__}