fix(geo_common): check for invalid bbox where min=max

This condition will cause Elasticsearch to throw an error, we should
catch it outselves first.

The error is more friendly than the case where min>max, but still an
error.

Connects https://github.com/pelias/api/pull/1050

sanitizer/_geo_common.js

@@ -48,7 +48,7 @@ function sanitize_bbox_min_max(raw, key_prefix) {
     const max = parseFloat(raw[`${key_prefix}.max_${dimension}`]);
     const min = parseFloat(raw[`${key_prefix}.min_${dimension}`]);
 
-    if (max < min) {
+    if (max <= min) {
       throw new Error(`min_${dimension} is larger than max_${dimension} in ${key_prefix}`);
     }
   });

test/unit/sanitizer/_geo_common.js

@@ -241,13 +241,12 @@ module.exports.tests.rect = function(test, common) {
     };
     var mandatory = false;
 
-    sanitize.sanitize_rect( 'boundary.rect', clean, params, mandatory );
-    t.equal(clean['boundary.rect.min_lat'], params['boundary.rect.min_lat'], 'min_lat approved');
-    t.equal(clean['boundary.rect.max_lat'], params['boundary.rect.max_lat'], 'min_lat approved');
-    t.equal(clean['boundary.rect.min_lon'], params['boundary.rect.min_lon'], 'min_lat approved');
-    t.equal(clean['boundary.rect.max_lon'], params['boundary.rect.max_lon'], 'min_lat approved');
+    t.throws( function(){
+      sanitize.sanitize_rect( 'boundary.rect', clean, params, mandatory );
+    });
     t.end();
   });
+
   test('invalid rect - partially specified', function (t) {
     var clean = {};
     var params = {
@@ -299,6 +298,22 @@ module.exports.tests.rect = function(test, common) {
     t.end();
   });
 
+  test('invalid rect - max/min equal', function (t) {
+    var clean = {};
+    var params = {
+      'boundary.rect.max_lat': 52,
+      'boundary.rect.max_lon': 14,
+      'boundary.rect.min_lat': 52,
+      'boundary.rect.min_lon': 12
+    };
+    var mandatory = false;
+
+    t.throws( function() {
+      sanitize.sanitize_rect( 'boundary.rect', clean, params, mandatory );
+    });
+    t.end();
+  });
+
   test('invalid rect - out of range latitude', function(t) {
     var clean = {};
     var params = {