From a419a51132bb1c4b8ac9d7f4ac7d714ea3ed8bcd Mon Sep 17 00:00:00 2001
From: Mehdi Abaakouk <sileht@redhat.com>
Date: Tue, 4 Aug 2015 18:09:08 +0200
Subject: [PATCH] Add `len` extention to the json parser

This extends the jsonpath_rw parser with customisation
for gabbi.

This first one is `len`
---
 gabbi/case.py                     |  4 +--
 gabbi/gabbits_intercept/data.yaml |  1 +
 gabbi/json_parser.py              | 56 +++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 2 deletions(-)
 create mode 100644 gabbi/json_parser.py

diff --git a/gabbi/case.py b/gabbi/case.py
index 0d1a326..b557347 100644
--- a/gabbi/case.py
+++ b/gabbi/case.py
@@ -29,11 +29,11 @@
 import unittest
 from unittest import case
 
-import jsonpath_rw
 import six
 from six.moves.urllib import parse as urlparse
 import wsgi_intercept
 
+from gabbi import json_parser
 from gabbi import utils
 
 REPLACERS = [
@@ -193,7 +193,7 @@ def extract_json_path_value(data, path):
 
         The input data is a Python datastructre, not a JSON string.
         """
-        path_expr = jsonpath_rw.parse(path)
+        path_expr = json_parser.parse(path)
         matches = [match.value for match in path_expr.find(data)]
         try:
             return matches[0]
diff --git a/gabbi/gabbits_intercept/data.yaml b/gabbi/gabbits_intercept/data.yaml
index 9a63743..53829d1 100644
--- a/gabbi/gabbits_intercept/data.yaml
+++ b/gabbi/gabbits_intercept/data.yaml
@@ -25,6 +25,7 @@ tests:
       response_json_paths:
           $[0]: 1
           $[1]: 2
+          $.`len`: 2
 
     - name: load json file
       url: /
diff --git a/gabbi/json_parser.py b/gabbi/json_parser.py
new file mode 100644
index 0000000..cd4a088
--- /dev/null
+++ b/gabbi/json_parser.py
@@ -0,0 +1,56 @@
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import jsonpath_rw
+
+
+class Len(jsonpath_rw.JSONPath):
+    """The JSONPath referring to the len of the current object.
+
+    Concrete syntax is '`len`'.
+    """
+
+    def find(self, datum):
+        datum = jsonpath_rw.DatumInContext.wrap(datum)
+        try:
+            value = len(datum.value)
+        except TypeError:
+            return []
+        else:
+            return [jsonpath_rw.DatumInContext(value,
+                                               context=None,
+                                               path=Len())]
+
+    def __eq__(self, other):
+        return isinstance(other, Len)
+
+    def __str__(self):
+        return '`len`'
+
+    def __repr__(self):
+        return 'Len()'
+
+
+class GabbiJsonPathParser(jsonpath_rw.parser.JsonPathParser):
+    """Custom gabbi LALR-parser for JsonPath"""
+
+    def p_jsonpath_named_operator(self, p):
+        "jsonpath : NAMED_OPERATOR"
+        if p[1] == 'len':
+            p[0] = Len()
+        else:
+            super(GabbiJsonPathParser, self).p_jsonpath_named_operator(p)
+
+
+def parse(path):
+    return GabbiJsonPathParser().parse(path)