Rules: Add the 'braces' rule

yamllint/conf/default.yml

@@ -3,12 +3,12 @@
 rules:
   #block-sequence-indentation:
   #  present: yes
+  braces:
+    min-spaces-inside: 0
+    max-spaces-inside: 0
   brackets:
     min-spaces-inside: 0
     max-spaces-inside: 0
-  #braces:
-  #  min-spaces-inside: 0
-  #  max-spaces-inside: 0
   colons:
     max-spaces-before: 0
     max-spaces-after: 1

yamllint/rules/__init__.py

@@ -15,6 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from yamllint.rules import (
+    braces,
     brackets,
     colons,
     commas,
@@ -30,6 +31,7 @@ from yamllint.rules import (
 )
 
 _RULES = {
+    braces.ID: braces,
     brackets.ID: brackets,
     colons.ID: colons,
     commas.ID: commas,

yamllint/rules/braces.py

@@ -0,0 +1,47 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2016 Adrien Vergé
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import yaml
+
+from yamllint.rules.common import spaces_after, spaces_before
+
+
+ID = 'braces'
+TYPE = 'token'
+CONF = {'min-spaces-inside': int,
+        'max-spaces-inside': int}
+
+
+def check(conf, token, prev, next):
+    if isinstance(token, yaml.FlowMappingStartToken):
+        problem = spaces_after(token, prev, next,
+                               min=conf['min-spaces-inside'],
+                               max=conf['max-spaces-inside'],
+                               min_desc='too few spaces inside braces',
+                               max_desc='too many spaces inside braces')
+        if problem is not None:
+            yield problem
+
+    elif (isinstance(token, yaml.FlowMappingEndToken) and
+            (prev is None or
+             not isinstance(prev, yaml.FlowMappingStartToken))):
+        problem = spaces_before(token, prev, next,
+                                min=conf['min-spaces-inside'],
+                                max=conf['max-spaces-inside'],
+                                min_desc='too few spaces inside braces',
+                                max_desc='too many spaces inside braces')
+        if problem is not None:
+            yield problem