Compute distance for each result of reverse query

helper/geojsonify.js

@@ -19,7 +19,8 @@ var DETAILS_PROPS = [
   'localadmin',
   'locality',
   'neighbourhood',
-  'confidence'
+  'confidence',
+  'distance'
 ];
 
 

middleware/distance.js

@@ -0,0 +1,32 @@
+var geolib = require('geolib');
+
+
+function setup() {
+
+  return computeDistances;
+}
+
+function computeDistances(req, res, next) {
+
+  // do nothing if no result data set
+  if (!req.results || !req.results.data) {
+    return next();
+  }
+
+  if ( !(req.clean.hasOwnProperty('lat') && req.clean.hasOwnProperty('lon')) ) {
+    return next();
+  }
+
+  req.results.data.forEach(function (place) {
+    // the result of getDistance is in meters, so convert to kilometers
+    place.distance = geolib.getDistance(
+      { latitude: req.clean.lat, longitude: req.clean.lon },
+      { latitude: place.center_point.lat, longitude: place.center_point.lon }
+    ) / 1000;
+  });
+
+  next();
+}
+
+
+module.exports = setup;

package.json

@@ -41,6 +41,7 @@
     "extend": "2.0.1",
     "geojson": "^0.2.1",
     "geojson-extent": "^0.3.1",
+    "geolib": "^2.0.18",
     "geopipes-elasticsearch-backend": "^0.2.0",
     "is-object": "^1.0.1",
     "markdown": "0.5.0",

routes/v1.js

@@ -25,6 +25,7 @@ var controllers     = {
 /** ----------------------- controllers ----------------------- **/
 
 var postProc = {
+  distances: require('../middleware/distance'),
   confidenceScores: require('../middleware/confidenceScore'),
   renamePlacenames: require('../middleware/renamePlacenames'),
   geocodeJSON: require('../middleware/geocodeJSON'),
@@ -70,6 +71,7 @@ function addRoutes(app, peliasConfig) {
       sanitisers.reverse.middleware,
       controllers.search(undefined, reverseQuery),
       // TODO: add confidence scores
+      postProc.distances(),
       postProc.renamePlacenames(),
       postProc.geocodeJSON(peliasConfig),
       postProc.sendJSON

test/unit/middleware/distance.js

@@ -0,0 +1,41 @@
+var distance = require('../../../middleware/distance')();
+
+module.exports.tests = {};
+
+module.exports.tests.computeDistance = function(test, common) {
+  test('valid lat/lon and results', function(t) {
+    var req = {
+      clean: {
+        lat: 45,
+        lon: -77
+      },
+      results: {
+        data: [
+          {
+            center_point: {
+              lat: 40,
+              lon: -71
+            }
+          }
+        ]
+      }
+    };
+
+    var expected = 742.348;
+    distance(req, null, function () {
+      t.equal(req.results.data[0].distance, expected, 'correct distance computed');
+      t.end();
+    });
+  });
+};
+
+module.exports.all = function (tape, common) {
+
+  function test(name, testFunction) {
+    return tape('[middleware] distance: ' + name, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};

test/unit/run.js

@@ -22,6 +22,7 @@ var tests = [
   require('./helper/outputSchema'),
   require('./helper/types'),
   require('./sanitiser/_geo_common'),
+  require('./middleware/distance'),
 ];
 
 tests.map(function(t) {