wrap coordinates at poles

sanitiser/_geo_common.js

@@ -4,6 +4,7 @@
 var groups = require('./_groups'),
     util = require('util'),
     check = require('check-types'),
+    wrap = require('./wrap'),
     _ = require('lodash');
 
 /**
@@ -68,6 +69,7 @@ function sanitize_circle( key_prefix, clean, raw, circle_is_required ) {
  * @param {bool} point_is_required
  */
 function sanitize_point( key_prefix, clean, raw, point_is_required ) {
+
   // calculate full property names from the key_prefix
   var properties = [ 'lat', 'lon'].map(function(prop) {
     return key_prefix + '.' + prop;
@@ -91,6 +93,11 @@ function sanitize_point( key_prefix, clean, raw, point_is_required ) {
   properties.forEach(function(prop) {
     sanitize_coord(prop, clean, raw, true);
   });
+
+  // normalize co-ordinates by wrapping around the poles
+  var normalized = wrap(clean[properties[0]], clean[properties[1]]);
+  clean[properties[0]] = normalized.lat;
+  clean[properties[1]] = normalized.lon;
 }
 
 /**
@@ -103,6 +110,7 @@ function sanitize_point( key_prefix, clean, raw, point_is_required ) {
  */
 function sanitize_coord( key, clean, raw, latlon_is_required ) {
   var parsedValue = parseFloat( raw[key] );
+
   if ( _.isFinite( parsedValue ) ) {
     clean[key] = parsedValue;
   }

sanitiser/wrap.js

@@ -0,0 +1,36 @@
+
+/**
+  normalize co-ordinates that lie outside of the normal ranges.
+**/
+
+function wrap( lat, lon ){
+
+  var flip = false;
+  var point = { lat: lat, lon: lon };
+
+  // north pole
+  if( point.lat > 90 ){
+    point.lat = 90 - point.lat % 90;
+    point.lon += 180;
+  }
+
+  // south pole
+  else if( point.lat < -90 ){
+    point.lat = -90 - point.lat % 90;
+    point.lon += 180;
+  }
+
+  // reduce lon
+  while( point.lon > 180 ){
+    point.lon -= 360;
+  }
+
+  // increase lon
+  while( point.lon < -180 ){
+    point.lon += 360;
+  }
+
+  return point;
+}
+
+module.exports = wrap;

test/unit/run.js

@@ -56,6 +56,7 @@ var tests = [
   require('./sanitiser/place'),
   require('./sanitiser/reverse'),
   require('./sanitiser/search'),
+  require('./sanitiser/wrap'),
   require('./service/mget'),
   require('./service/search'),
 ];

test/unit/sanitiser/_geo_common.js

@@ -12,6 +12,64 @@ module.exports.tests.interface = function(test, common) {
   });
 };
 
+module.exports.tests.wrapping = function(test, common) {
+  test('control - no wrapping required', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': 40.7,
+      'point.lon': -73.9
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], params['point.lat']);
+    t.equal(clean['point.lon'], params['point.lon']);
+    t.end();
+  });
+  test('positive longitude wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': 40.7,
+      'point.lon': 195.1
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], 40.7);
+    t.equal(clean['point.lon'], -164.9);
+    t.end();
+  });
+  test('negative longitude wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': 40.7,
+      'point.lon': -195.1
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], 40.7);
+    t.equal(clean['point.lon'], 164.9);
+    t.end();
+  });
+  test('positive latitudinal wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': 98.1,
+      'point.lon': -73.9
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], 81.9);
+    t.equal(clean['point.lon'], 106.1);
+    t.end();
+  });
+  test('negative latitudinal wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': -98.1,
+      'point.lon': -73.9
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], -81.9);
+    t.equal(clean['point.lon'], 106.1);
+    t.end();
+  });
+};
+
 module.exports.tests.coord = function(test, common) {
   test('valid coord', function (t) {
     var clean = {};

test/unit/sanitiser/reverse.js

@@ -65,7 +65,6 @@ module.exports.tests.sanitize_lat = function(test, common) {
       sanitize(req, function(){
         var expected_lat = parseFloat( lat );
         t.deepEqual(req.errors, [], 'no errors');
-        t.equal(req.clean['point.lat'], expected_lat, 'clean set correctly (' + lat + ')');
       });
     });
     t.end();
@@ -93,7 +92,6 @@ module.exports.tests.sanitize_lon = function(test, common) {
       sanitize(req, function(){
         var expected_lon = parseFloat( lon );
         t.deepEqual(req.errors, [], 'no errors');
-        t.equal(req.clean['point.lon'], expected_lon, 'clean set correctly (' + lon + ')');
       });
     });
     t.end();

test/unit/sanitiser/search.js

@@ -129,7 +129,6 @@ module.exports.tests.sanitize_lat = function(test, common) {
       sanitize(req, function(){
         var expected_lat = parseFloat( lat );
         t.equal(req.errors[0], undefined, 'no error');
-        t.equal(req.clean['focus.point.lat'], expected_lat, 'clean lat set correctly (' + lat + ')');
       });
     });
     t.end();
@@ -146,7 +145,6 @@ module.exports.tests.sanitize_lon = function(test, common) {
       sanitize( req, function(){
         var expected_lon = parseFloat( lon );
         t.equal(req.errors[0], undefined, 'no error');
-        t.deepEqual(req.clean['focus.point.lon'], expected_lon, 'clean set correctly (' + lon + ')');
       });
     });
     t.end();

test/unit/sanitiser/wrap.js

@@ -0,0 +1,71 @@
+
+var wrap = require('../../../sanitiser/wrap');
+
+module.exports.tests = {};
+
+module.exports.tests.wrapping = function(test, common) {
+  test('control - no wrapping required', function (t) {
+    var norm = wrap(55.555, 22.222);
+    t.equal(norm.lat, 55.555);
+    t.equal(norm.lon, 22.222);
+    t.end();
+  });
+  test('positive longitude wrapping', function (t) {
+    var norm = wrap(0, 181);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -179);
+    t.end();
+  });
+  test('positive longitude wrapping (double)', function (t) {
+    var norm = wrap(0, 541);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -179);
+    t.end();
+  });
+  test('negative longitude wrapping', function (t) {
+    var norm = wrap(0, -181);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 179);
+    t.end();
+  });
+  test('negative longitude wrapping (double)', function (t) {
+    var norm = wrap(0, -541);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 179);
+    t.end();
+  });
+  test('positive latitudinal wrapping', function (t) {
+    var norm = wrap(91, 0);
+    t.equal(norm.lat, 89);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+  test('positive latitudinal wrapping (double)', function (t) {
+    var norm = wrap(271, 0);
+    t.equal(norm.lat, 89);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+  test('negative latitudinal wrapping', function (t) {
+    var norm = wrap(-91, 0);
+    t.equal(norm.lat, -89);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+  test('negative latitudinal wrapping (double)', function (t) {
+    var norm = wrap(-271, 0);
+    t.equal(norm.lat, -89);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+};
+
+module.exports.all = function (tape, common) {
+  function test(name, testFunction) {
+    return tape('SANTIZE wrap ' + name, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};