diff --git a/extension/background.ts b/extension/background.ts
index c99e249c6..3321ad28a 100644
--- a/extension/background.ts
+++ b/extension/background.ts
@@ -41,6 +41,9 @@ chrome.runtime.onMessage.addListener(async (request, sender, response) => {
       break;
     case 'xsearch':
       console.log('xsearch');
+      if (request.text === '') {
+        break;
+      }
       response(rcxMain.search(request.text, request.dictOption));
       break;
     case 'resetDict':
diff --git a/extension/rikaichan.ts b/extension/rikaichan.ts
index 7822fb2c3..0b8466aa8 100644
--- a/extension/rikaichan.ts
+++ b/extension/rikaichan.ts
@@ -263,7 +263,6 @@ class RcxMain {
 
     const m = this.showMode;
     let e: DictEntryData | null = null;
-
     do {
       switch (this.showMode) {
         case 0:
diff --git a/extension/test/background_test.ts b/extension/test/background_test.ts
index 7e72d01c2..d03b240b5 100644
--- a/extension/test/background_test.ts
+++ b/extension/test/background_test.ts
@@ -6,7 +6,6 @@ import sinon from 'sinon';
 import sinonChai from 'sinon-chai';
 
 use(sinonChai);
-
 let rcxMain: RcxMain;
 
 describe('background.ts', function () {
@@ -66,24 +65,72 @@ describe('background.ts', function () {
       );
     });
   });
+
+  describe('xsearch', function () {
+    it('should call response callback with search correct values', async function () {
+      rcxMain.search = sinon
+        .stub()
+        .returns({ text: 'theText', dictOptions: '0' });
+      const response = sinon.spy();
+
+      await sendMessageToBackground({
+        tabId: 0,
+        type: 'xsearch',
+        text: 'A non empty string',
+        responseCallback: response,
+      });
+
+      expect(response).to.have.been.calledWithMatch({
+        text: 'theText',
+        dictOptions: sinon.match.any,
+      });
+      expect(response).to.have.been.calledOnce;
+    });
+
+    it('should not search if request.text is an empty string', async function () {
+      const response = sinon.spy();
+
+      await sendMessageToBackground({
+        tabId: 0,
+        type: 'xsearch',
+        text: '',
+        responseCallback: response,
+      });
+
+      expect(response.called).to.be.false;
+    });
+  });
 });
 
+type Payload = {
+  tabId?: number;
+  text?: string;
+  type: string;
+  responseCallback?: (response: unknown) => void;
+};
+
 async function sendMessageToBackground({
   tabId = 0,
   type,
+  text,
   responseCallback = () => {
     // Do nothing by default.
   },
-}: {
-  tabId?: number;
-  type: string;
-  responseCallback?: (response: unknown) => void;
-}): Promise<void> {
+}: Payload): Promise<void> {
+  const request: { type: string; text?: string } = {
+    type,
+  };
+  const sender = {
+    tab: { id: tabId },
+  };
+  if (text !== undefined) {
+    request['text'] = text;
+  }
   // In background.ts, a promise is passed to `addListener` so we can await it here.
   // eslint-disable-next-line @typescript-eslint/await-thenable
   await chrome.runtime.onMessage.addListener.yield(
-    { type: type },
-    { tab: { id: tabId } },
+    request,
+    sender,
     responseCallback
   );
   return;
diff --git a/package.json b/package.json
index f616c97f3..10825f583 100644
--- a/package.json
+++ b/package.json
@@ -27,6 +27,7 @@
     "test": "wtr \"extension/test/*_test.ts\"",
     "test:small": "wtr --files \"extension/test/background_test.ts\" \"extension/test/data_test.ts\" \"extension/test/docs-annotate-canvas_test.ts\" \"extension/test/rikaicontent_test.ts\"",
     "test:browserstack": "npm run test -- --browserstack",
+    "test:tiny": "wtr --files \"extension/test/background_test.ts\"",
     "test:watch": "npm run test -- --watch",
     "test:update-baselines": "npm run test -- --update-visual-baseline",
     "update-db": "node --loader ts-node/esm utils/update-db.ts"