respond with user-id and client in the headers

added headers to the test-client callback to be able to check them

lib/api/middlewares/client-header.js

@@ -0,0 +1,13 @@
+'use strict';
+
+module.exports = function clientHeader () {
+    return function clientHeaderMiddleware (req, res, next) {
+        const { client } = req.query;
+
+        if (client) {
+            res.set('Carto-Client', client);
+        }
+
+        return next();
+    };
+};

lib/api/middlewares/user.js

@@ -19,6 +19,7 @@ module.exports = function user (metadataBackend) {
             }
 
             res.locals.userId = userId;
+            res.set('Carto-User-Id', `${userId}`);
             return next();
         });
     };

lib/api/sql/query-controller.js

@@ -19,6 +19,7 @@ const surrogateKey = require('../middlewares/surrogate-key');
 const lastModified = require('../middlewares/last-modified');
 const formatter = require('../middlewares/formatter');
 const content = require('../middlewares/content');
+const clientHeader = require('../middlewares/client-header');
 
 const { RATE_LIMIT_ENDPOINTS_GROUPS } = rateLimits;
 const PSQL = require('cartodb-psql');
@@ -55,6 +56,7 @@ module.exports = class QueryController {
                 lastModified(),
                 formatter(),
                 content(),
+                clientHeader(),
                 handleQuery({ stats: this.stats })
             ];
         };

test/acceptance/client-headers-test.js

@@ -0,0 +1,43 @@
+'use strict';
+
+const assert = require('../support/assert');
+const TestClient = require('../support/test-client');
+
+describe('SQL api metric headers', function () {
+    const publicSQL = 'select * from untitle_table_4';
+
+    it('should get client header if client param is present', function (done) {
+        this.testClient = new TestClient();
+        const params = { client: 'test' };
+
+        this.testClient.getResult(publicSQL, params, (err, result, headers) => {
+            assert.ifError(err);
+            assert.strictEqual(result.length, 6);
+            assert.strictEqual(headers['carto-client'], 'test');
+            done();
+        });
+    });
+
+    it('should not get the client header if no client is provided', function (done) {
+        this.testClient = new TestClient();
+
+        this.testClient.getResult(publicSQL,  (err, result, headers) => {
+            assert.ifError(err);
+            assert.strictEqual(result.length, 6);
+            assert.strictEqual(headers['carto-client'], undefined);
+            done();
+        });
+    });
+
+    it('should not get the user id in the response header', function (done) {
+        this.testClient = new TestClient();
+
+        this.testClient.getResult(publicSQL, (err, result, headers) => {
+            assert.ifError(err);
+            assert.strictEqual(result.length, 6);
+            assert.strictEqual(headers['carto-user-id'], '1');
+            done();
+        });
+    });
+
+});

test/support/test-client.js

@@ -56,10 +56,10 @@ TestClient.prototype.getResult = function (query, override, callback) {
             var result = JSON.parse(res.body);
 
             if (res.statusCode > 299) {
-                return callback(null, result);
+                return callback(null, result, res.headers);
             }
 
-            return callback(null, result.rows || [], result);
+            return callback(null, result.rows, res.headers || [], result, res.headers);
         }
     );
 };
@@ -89,7 +89,11 @@ TestClient.prototype.getUrl = function (override) {
         return '/api/v1/sql?';
     }
 
-    return '/api/v2/sql?api_key=' + (override.apiKey || this.config.apiKey || '1234');
+    let url = '/api/v2/sql?api_key=' + (override.apiKey || this.config.apiKey || '1234');
+    if (override.client) {
+        url = url + '&client=' + override.client;
+    }
+    return url;
 };
 
 TestClient.prototype.getExpectedResponse = function (override) {