diff --git a/docs/rules.rst b/docs/rules.rst
index da744a0..dab310d 100644
--- a/docs/rules.rst
+++ b/docs/rules.rst
@@ -74,6 +74,11 @@ key-duplicates
.. automodule:: yamllint.rules.key_duplicates
+key-ordering
+--------------
+
+.. automodule:: yamllint.rules.key_ordering
+
line-length
-----------
diff --git a/tests/rules/test_key_ordering.py b/tests/rules/test_key_ordering.py
new file mode 100644
index 0000000..bcd9eef
--- /dev/null
+++ b/tests/rules/test_key_ordering.py
@@ -0,0 +1,67 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2017 Johannes F. Knauf
+#
+# 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 .
+
+from tests.common import RuleTestCase
+
+
+class KeyOrderingTestCase(RuleTestCase):
+ rule_id = 'key-ordering'
+
+ def test_disabled(self):
+ conf = 'key-ordering: disable'
+ self.check('---\n'
+ 'block mapping:\n'
+ ' secondkey: a\n'
+ ' firstkey: b\n', conf)
+ self.check('---\n'
+ 'flow mapping:\n'
+ ' {secondkey: a, firstkey: b}\n', conf)
+ self.check('---\n'
+ 'second: before_first\n'
+ 'at: root\n', conf)
+ self.check('---\n'
+ 'nested but OK:\n'
+ ' second: {first: 1}\n'
+ ' third:\n'
+ ' second: 2\n', conf)
+
+ def test_enabled(self):
+ conf = 'key-ordering: enable'
+ self.check('---\n'
+ 'block mapping:\n'
+ ' secondkey: a\n'
+ ' firstkey: b\n', conf,
+ problem=(4, 3))
+ self.check('---\n'
+ 'flow mapping:\n'
+ ' {secondkey: a, firstkey: b}\n', conf,
+ problem=(3, 18))
+ self.check('---\n'
+ 'second: before_first\n'
+ 'at: root\n', conf,
+ problem=(3, 1))
+ self.check('---\n'
+ 'nested but OK:\n'
+ ' second: {first: 1}\n'
+ ' third:\n'
+ ' second: 2\n', conf)
+
+ def test_key_tokens_in_flow_sequences(self):
+ conf = 'key-ordering: enable'
+ self.check('---\n'
+ '[\n'
+ ' key: value, mappings, in, flow: sequence\n'
+ ']\n', conf)
diff --git a/yamllint/conf/default.yaml b/yamllint/conf/default.yaml
index c7c4da4..57cff64 100644
--- a/yamllint/conf/default.yaml
+++ b/yamllint/conf/default.yaml
@@ -39,6 +39,7 @@ rules:
indent-sequences: true
check-multi-line-strings: false
key-duplicates: enable
+ key-ordering: disable
line-length:
max: 80
allow-non-breakable-words: true
diff --git a/yamllint/rules/__init__.py b/yamllint/rules/__init__.py
index 619e32d..83dca76 100644
--- a/yamllint/rules/__init__.py
+++ b/yamllint/rules/__init__.py
@@ -27,6 +27,7 @@ from yamllint.rules import (
hyphens,
indentation,
key_duplicates,
+ key_ordering,
line_length,
new_line_at_end_of_file,
new_lines,
@@ -47,6 +48,7 @@ _RULES = {
hyphens.ID: hyphens,
indentation.ID: indentation,
key_duplicates.ID: key_duplicates,
+ key_ordering.ID: key_ordering,
line_length.ID: line_length,
new_line_at_end_of_file.ID: new_line_at_end_of_file,
new_lines.ID: new_lines,
diff --git a/yamllint/rules/key_ordering.py b/yamllint/rules/key_ordering.py
new file mode 100644
index 0000000..4a7e31f
--- /dev/null
+++ b/yamllint/rules/key_ordering.py
@@ -0,0 +1,86 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2017 Johannes F. Knauf
+#
+# 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 .
+
+"""
+Use this rule to enforce alphabetical ordering of keys in mappings.
+
+.. rubric:: Examples
+
+#. With ``key-ordering: {}``
+
+ the following code snippet would **PASS**:
+ ::
+
+ - key 1: v
+ key 2: val
+ key 3: value
+ - {a: 1, b: 2, c: 3}
+
+ the following code snippet would **FAIL**:
+ ::
+
+ - key 2: v
+ key 1: val
+
+ the following code snippet would **FAIL**:
+ ::
+
+ - {b: 1, a: 2}
+"""
+
+import yaml
+
+from yamllint.linter import LintProblem
+
+
+ID = 'key-ordering'
+TYPE = 'token'
+CONF = {}
+
+MAP, SEQ = range(2)
+
+
+class Parent(object):
+ def __init__(self, type):
+ self.type = type
+ self.keys = []
+
+
+def check(conf, token, prev, next, nextnext, context):
+ if 'stack' not in context:
+ context['stack'] = []
+
+ if isinstance(token, (yaml.BlockMappingStartToken,
+ yaml.FlowMappingStartToken)):
+ context['stack'].append(Parent(MAP))
+ elif isinstance(token, (yaml.BlockSequenceStartToken,
+ yaml.FlowSequenceStartToken)):
+ context['stack'].append(Parent(SEQ))
+ elif isinstance(token, (yaml.BlockEndToken,
+ yaml.FlowMappingEndToken,
+ yaml.FlowSequenceEndToken)):
+ context['stack'].pop()
+ elif (isinstance(token, yaml.KeyToken) and
+ isinstance(next, yaml.ScalarToken)):
+ # This check is done because KeyTokens can be found inside flow
+ # sequences... strange, but allowed.
+ if len(context['stack']) > 0 and context['stack'][-1].type == MAP:
+ if any(next.value < key for key in context['stack'][-1].keys):
+ yield LintProblem(
+ next.start_mark.line + 1, next.start_mark.column + 1,
+ 'wrong ordering of key "%s" in mapping' % next.value)
+ else:
+ context['stack'][-1].keys.append(next.value)