Add test to chek we still send events when errored map static tile

lib/api/middlewares/pubsub-metrics.js

@@ -78,7 +78,7 @@ function getResponseTime (res) {
         return undefined;
     }
 
-    return stats.total.toString();
+    return stats && stats.total ? stats.total.toString() : undefined;
 }
 
 function getFromReq (req, { query = {}, body = {}, params = {}, headers = {} } = {}) {

test/integration/pubsub-metrics-test.js

@@ -418,4 +418,45 @@ describe('pubsub metrics middleware', function () {
             return testClient.drain(done);
         });
     });
+
+    it('should send event for errored static named map requests', function (done) {
+        const expectedEvent = 'map_view';
+        const expectedMetricsEvent = 'event-test';
+        const expectedEventSource = 'event-source-test';
+        const expectedEventGroupId = '1';
+        const expectedResponseCode = '400';
+        const expectedMapType = 'static';
+        const extraHeaders = {
+            'Carto-Event': expectedMetricsEvent,
+            'Carto-Event-Source': expectedEventSource,
+            'Carto-Event-Group-Id': expectedEventGroupId
+        };
+        const overrideServerOptions = { pubSubMetrics: { enabled: true, topic: 'topic-test' } };
+        const template = templateBuilder({ name: 'preview-errored' });
+        const testClient = new TestClient(template, apikey, extraHeaders, overrideServerOptions);
+        const widthTooLarge = 8193;
+        const params = {
+            response: {
+                status: 400,
+                headers: {
+                    'Content-Type': 'application/json; charset=utf-8'
+                }
+            }
+        };
+
+        testClient.getPreview(widthTooLarge, 480, params, (err, res, body) => {
+            if (err) {
+                return done(err);
+            }
+
+            assert.strictEqual(this.pubSubMetricsBackendSendMethodCalledWith.event, expectedEvent);
+            assert.strictEqual(this.pubSubMetricsBackendSendMethodCalledWith.attributes.metrics_event, expectedMetricsEvent);
+            assert.strictEqual(this.pubSubMetricsBackendSendMethodCalledWith.attributes.event_source, expectedEventSource);
+            assert.strictEqual(this.pubSubMetricsBackendSendMethodCalledWith.attributes.event_group_id, expectedEventGroupId);
+            assert.strictEqual(this.pubSubMetricsBackendSendMethodCalledWith.attributes.response_code, expectedResponseCode);
+            assert.strictEqual(this.pubSubMetricsBackendSendMethodCalledWith.attributes.map_type, expectedMapType);
+
+            return testClient.drain(done);
+        });
+    });
 });

test/support/test-client.js

@@ -1788,11 +1788,10 @@ TestClient.prototype.getPreview = function (width, height, params = {}, callback
                 return callback(err);
             }
 
-            this.keysToDelete['user:localhost:mapviews:global'] = 5;
-
             let body;
             switch (res.headers['content-type']) {
             case 'image/png':
+                this.keysToDelete['user:localhost:mapviews:global'] = 5;
                 body = mapnik.Image.fromBytes(Buffer.from(res.body, 'binary'));
                 break;
             case 'application/json; charset=utf-8':