feature: S3C-1183 add GCP Tag functional tests

Adds GCP S3 functional test for object tagging

tests/functional/aws-node-sdk/test/multipleBackend/objectTagging/objectTagging.js

@@ -99,6 +99,30 @@ function azureGet(key, tagCheck, isEmpty, callback) {
     });
 }
 
+function gcpGet(key, tagCheck, isEmpty, isMpu, callback) {
+    process.stdout.write('Getting object from GCP\n');
+    gcpClient.getObject({
+        Bucket: gcpBucket,
+        Key: key,
+    }, (err, res) => {
+        assert.equal(err, null);
+        if (isEmpty) {
+            assert.strictEqual(res.ETag, `"${emptyMD5}"`);
+        } else if (isMpu) {
+            assert.strictEqual(res.ETag, `"${mpuMD5}"`);
+        } else {
+            assert.strictEqual(res.ETag, `"${correctMD5}"`);
+        }
+        if (tagCheck) {
+            const tags = GcpUtils.retrieveTags(res.Metdata);
+            assert.strictEqual(tags, tagObj);
+        } else {
+            assert.strictEqual(res.metadata.tags, undefined);
+        }
+        return callback();
+    });
+}
+
 function getObject(key, backend, tagCheck, isEmpty, isMpu, callback) {
     function get(cb) {
         process.stdout.write('Getting object\n');
@@ -127,6 +151,10 @@ function getObject(key, backend, tagCheck, isEmpty, isMpu, callback) {
         setTimeout(() => {
             get(() => azureGet(key, tagCheck, isEmpty, callback));
         }, cloudTimeout);
+    } else if (backend === 'gcp') {
+        setTimeout(() => {
+            get(() => gcpGet(key, tagCheck, isEmpty, isMpu, callback));
+        }, cloudTimeout);
     } else {
         get(callback);
     }