Merge pull request #712 from CartoDB/mvt-no-content

Respond with 204 when mvt is empty

NEWS.md

@@ -3,6 +3,8 @@
 ## 3.9.7
 Released 2017-mm-dd
 
+ - Respond with 204 (No content) when vector tile has no data #712
+
 
 ## 3.9.6
 Released 2017-07-11

lib/cartodb/controllers/base.js

@@ -201,6 +201,10 @@ BaseController.prototype.sendError = function(req, res, err, label) {
 
     var statusCode = findStatusCode(err);
 
+    if (err.message === 'Tile does not exist' && req.params.format === 'mvt') {
+        statusCode = 204;
+    }
+
     debug('[%s ERROR] -- %d: %s, %s', label, statusCode, err, err.stack);
 
     // If a callback was requested, force status to 200

test/acceptance/mvt.js

@@ -0,0 +1,53 @@
+require('../support/test_helper');
+
+const assert = require('../support/assert');
+const TestClient = require('../support/test-client');
+
+function createMapConfig (sql = TestClient.SQL.ONE_POINT) {
+    return {
+        version: '1.6.0',
+        layers: [{
+            type: "cartodb",
+            options: {
+                sql: sql,
+                cartocss: TestClient.CARTOCSS.POINTS,
+                cartocss_version: '2.3.0',
+                interactivity: 'cartodb_id'
+            }
+        }]
+    };
+}
+
+describe('mvt', function () {
+    const testCases = [
+        {
+            desc: 'should get empty mvt with code 204 (no content)',
+            coords: { z: 0, x: 0, y: 0 },
+            format: 'mvt',
+            status: 204,
+            mapConfig: createMapConfig(TestClient.SQL.EMPTY)
+        },
+        {
+            desc: 'should get mvt tile with code 200 (ok)',
+            coords: { z: 0, x: 0, y: 0 },
+            format: 'mvt',
+            status: 200,
+            mapConfig: createMapConfig()
+        }
+    ];
+
+    testCases.forEach(function (test) {
+        it(test.desc, done => {
+            const testClient = new TestClient(test.mapConfig, 1234);
+            const { z, x, y } = test.coords;
+            const { format, status } = test;
+
+            testClient.getTile(z, x, y, { format, status }, (err, res) => {
+                assert.ifError(err);
+
+                assert.equal(res.statusCode, test.status);
+                testClient.drain(done);
+            });
+        });
+    });
+});

test/support/test-client.js

@@ -75,6 +75,11 @@ module.exports.CARTOCSS = {
     ].join('\n')
 };
 
+module.exports.SQL = {
+    EMPTY: 'select 1 as cartodb_id, null::geometry as the_geom_webmercator',
+    ONE_POINT: 'select 1 as cartodb_id, \'SRID=3857;POINT(0 0)\'::geometry the_geom_webmercator'
+}
+
 TestClient.prototype.getWidget = function(widgetName, params, callback) {
     var self = this;
 
@@ -525,7 +530,7 @@ TestClient.prototype.getTile = function(z, x, y, params, callback) {
             };
 
             var expectedResponse = {
-                status: 200,
+                status: params.status || 200,
                 headers: {
                     'Content-Type': 'application/json; charset=utf-8'
                 }
@@ -542,7 +547,12 @@ TestClient.prototype.getTile = function(z, x, y, params, callback) {
 
             if (isMvt) {
                 request.encoding = 'binary';
+
+                if (expectedResponse.status === 200) {
                     expectedResponse.headers['Content-Type'] = 'application/x-protobuf';
+                } else if (expectedResponse.status === 204) {
+                    expectedResponse.headers['Content-Type'] = undefined;
+                }
             }
 
             var isGeojson = format.match(/geojson$/);
@@ -561,16 +571,17 @@ TestClient.prototype.getTile = function(z, x, y, params, callback) {
 
             assert.response(server, request, expectedResponse, function(res, err) {
                 assert.ifError(err);
-
                 var obj;
 
                 if (isPng) {
                     obj = mapnik.Image.fromBytes(new Buffer(res.body, 'binary'));
                 }
                 else if (isMvt) {
+                    if (res.body) {
                         obj = new mapnik.VectorTile(z, x, y);
                         obj.setDataSync(new Buffer(res.body, 'binary'));
                     }
+                }
                 else {
                     obj = JSON.parse(res.body);
                 }