diff --git a/azure-pipelines/ci.yml b/azure-pipelines/ci.yml
index b34487e..a86b31c 100644
--- a/azure-pipelines/ci.yml
+++ b/azure-pipelines/ci.yml
@@ -39,6 +39,9 @@ jobs:
       - script: 'npx @microsoft/rush sync-versions && npx @microsoft/rush update && npx @microsoft/rush rebuild'
         displayName: 'npm build'
 
+      - script: 'npm test'
+        displayName: 'npm test'
+
       - script: 'npx @microsoft/rush publish --publish --pack --include-all --tag latest'
         displayName: 'npm pack'
 
diff --git a/src/helper.ts b/src/helper.ts
index 9895298..f0be78f 100644
--- a/src/helper.ts
+++ b/src/helper.ts
@@ -168,7 +168,7 @@ export class Helper {
             return;
         }
 
-        let up1 = (n: string) => n.length == 1 ? n.toUpperCase() : n[0].toUpperCase().concat(n.substr(1).toLowerCase());
+        let up1 = (n: string) => Helper.isEmptyString(n) ? n : n.length == 1 ? n.toUpperCase() : n[0].toUpperCase().concat(n.substr(1).toLowerCase());
         let op = {};
         op[CliConst.NamingStyle.camel] = {
             wording: (v: string, i: number) => i === 0 ? v.toLowerCase() : up1(v),