From 046ee8c1a0f32f068a0caba81103e83999eb3cca Mon Sep 17 00:00:00 2001
From: Rufus Pollock <rufus.pollock@okfn.org>
Date: Fri, 12 Oct 2012 22:29:55 +0100
Subject: [PATCH] [#240,bugfix,backend/memory][s]: range filters now work as
 expected when one end of range is null - fixes #240.

* see ticket and comments for more details
---
 src/backend.memory.js       |  9 ++++++++-
 test/backend.memory.test.js | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/src/backend.memory.js b/src/backend.memory.js
index 90748d9a..18ddadee 100644
--- a/src/backend.memory.js
+++ b/src/backend.memory.js
@@ -134,12 +134,19 @@ this.recline.Backend.Memory = this.recline.Backend.Memory || {};
       }
 
       function range(record, filter) {
+        var startnull = (filter.start == null || filter.start === '');
+        var stopnull = (filter.stop == null || filter.stop === '');
         var parse = getDataParser(filter);
         var value = parse(record[filter.field]);
         var start = parse(filter.start);
         var stop  = parse(filter.stop);
 
-        return (value >= start && value <= stop);
+        // if at least one end of range is set do not allow '' to get through
+        // note that for strings '' <= {any-character} e.g. '' <= 'a'
+        if ((!startnull || !stopnull) && value === '') {
+          return false;
+        }
+        return ((startnull || value >= start) && (stopnull || value <= stop));
       }
 
       function geo_distance() {
diff --git a/test/backend.memory.test.js b/test/backend.memory.test.js
index ffca17bd..5743d6d3 100644
--- a/test/backend.memory.test.js
+++ b/test/backend.memory.test.js
@@ -114,6 +114,42 @@ test('filters', function () {
   });
 });
 
+
+test('filters with nulls', function () {
+  var data = _wrapData();
+
+  query = new recline.Model.Query();
+  query.addFilter({type: 'range', field: 'z', start: '', stop: null});
+  data.query(query.toJSON()).then(function(out) {
+    equal(out.total, 6);
+  });
+
+  query = new recline.Model.Query();
+  query.addFilter({type: 'range', field: 'x', start: '', stop: '3'});
+  data.query(query.toJSON()).then(function(out) {
+    equal(out.total, 3);
+  });
+
+  query = new recline.Model.Query();
+  query.addFilter({type: 'range', field: 'x', start: '3', stop: ''});
+  data.query(query.toJSON()).then(function(out) {
+    equal(out.total, 4);
+  });
+
+  data.data[5].country = '';
+  query = new recline.Model.Query();
+  query.addFilter({type: 'range', field: 'country', start: '', stop: 'Z'});
+  data.query(query.toJSON()).then(function(out) {
+    equal(out.total, 5);
+  });
+
+  query = new recline.Model.Query();
+  query.addFilter({type: 'range', field: 'x', start: '', stop: ''});
+  data.query(query.toJSON()).then(function(out) {
+    equal(out.total, 6);
+  });
+});
+
 test('facet', function () {
   var data = _wrapData();
   var query = new recline.Model.Query();