diff --git a/src/App.tsx b/src/App.tsx
index 94e4442..76cde14 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -1,8 +1,10 @@
 /*  eslint-disable jsx-a11y/accessible-emoji */
-import React from "react";
+/**
+ * External modules
+ */
+import React, { useCallback, useEffect, useMemo, useState } from "react";
 import styled from "styled-components";
 import "antd/dist/antd.css";
-import "./App.css";
 import {
     Button,
     Input,
@@ -17,10 +19,15 @@ import {
     LoadingOutlined,
     ReloadOutlined,
 } from "@ant-design/icons";
+
+/**
+ * Internal modules
+ */
+import "./App.css";
 import { AddressData, AddressManager } from "./AddressManager";
 import { AddressList } from "./components/AddressList";
-import { getRuntime } from "./utils";
 import { SettingsManager, Settings } from "./SettingsManager";
+import { getRuntime } from "./utils";
 
 const Header = styled.div`
     position: fixed;
@@ -92,7 +99,7 @@ const ListEnd = styled.div`
     }
 `;
 
-const Spinner: React.FC = () => (
+const Spinner = () => (
     <Spin style={{ width: "100%", marginTop: "15px", marginBottom: "30px" }} indicator={<LoadingOutlined style={{ fontSize: 24 }} />} />
 );
 
@@ -103,25 +110,25 @@ interface Props {
 
 export const App = (props: Props) => {
     const { settings, address } = props;
-    const [searchValue, setSearchValue] = React.useState("");
-    const [showLoading, setShowLoading] = React.useState(false);
-    const [isEnd, setIsEnd] = React.useState(false);
-    const [showEngAddr, setShowEngAddr] = React.useState(true);
-    const [showRoadAddr, setShowRoadAddr] = React.useState(true);
-    const [showLegacyAddr, setShowLegacyAddr] = React.useState(true);
-    const [addressData, setAddressData] = React.useState<AddressData[]>([]);
-    const [updatingSettings, setUpdatingSettings] = React.useState(false);
+    const [searchValue, setSearchValue] = useState("");
+    const [loading, setLoading] = useState(false);
+    const [isEnd, setIsEnd] = useState(false);
+    const [showEngAddr, setShowEngAddr] = useState(true);
+    const [showRoadAddr, setShowRoadAddr] = useState(true);
+    const [showLegacyAddr, setShowLegacyAddr] = useState(true);
+    const [addressData, setAddressData] = useState<AddressData[]>([]);
+    const [updatingSettings, setUpdatingSettings] = useState(false);
 
-    const handleSearchValueChange = React.useCallback((e: React.ChangeEvent<HTMLInputElement>) => {
+    const handleSearchValueChange = useCallback((e: React.ChangeEvent<HTMLInputElement>) => {
         setSearchValue(e.target.value);
     }, [setSearchValue]);
 
-    const handleSearchClick = React.useCallback(() => {
+    const handleSearchClick = useCallback(() => {
         if (address.previousSearchKey?.keyword === searchValue) {
             return;
         }
 
-        setShowLoading(true);
+        setLoading(true);
         setAddressData([]);
 
         window.ga("send", "event", "address", "search", searchValue);
@@ -135,17 +142,17 @@ export const App = (props: Props) => {
         }).catch((err) => {
             console.error(err);
         }).finally(() => {
-            setShowLoading(false);
+            setLoading(false);
         });
-    }, [address, searchValue, setAddressData, setShowLoading]);
+    }, [address, searchValue]);
 
-    const handleResetClick = React.useCallback(() => {
+    const handleResetClick = useCallback(() => {
         setSearchValue("");
         handleSearchClick();
     //  eslint-disable-next-line react-hooks/exhaustive-deps
-    }, [setSearchValue]);
+    }, []);
 
-    const handleSearchOptionClick = React.useCallback((type: "eng" | "road" | "legacy") => async () => {
+    const handleSearchOptionClick = useCallback((type: "eng" | "road" | "legacy") => async () => {
         if (updatingSettings) {
             return;
         }
@@ -178,10 +185,10 @@ export const App = (props: Props) => {
         } finally {
             setUpdatingSettings(false);
         }
-    }, [settings, showEngAddr, showRoadAddr, showLegacyAddr, updatingSettings, setShowEngAddr, setShowRoadAddr, setShowLegacyAddr, setUpdatingSettings]);
+    }, [settings, showEngAddr, showRoadAddr, showLegacyAddr, updatingSettings]);
 
-    const loadNextAddress = React.useCallback(() => {
-        if (showLoading) {
+    const loadNextAddress = useCallback(() => {
+        if (loading) {
             return;
         }
         if (address.previousSearchKey?.end) {
@@ -190,7 +197,7 @@ export const App = (props: Props) => {
             return;
         }
 
-        setShowLoading(true);
+        setLoading(true);
         const nextPage = (Number.parseInt(address.previousSearchKey?.currentPage!) + 1).toString();
 
         window.ga("send", "event", "address", "search", "추가 데이터 로드", Number.parseInt(nextPage));
@@ -202,11 +209,11 @@ export const App = (props: Props) => {
         }).catch((err) => {
             console.error(err);
         }).finally(() => {
-            setShowLoading(false);
+            setLoading(false);
         });
-    }, [address, showLoading, setShowLoading]);
+    }, [address, loading]);
 
-    const Options = React.useMemo(() => [
+    const Options = useMemo(() => [
         <Button key={1} type="link" disabled={updatingSettings} onClick={handleSearchOptionClick("eng")}
             icon={showEngAddr ? <CheckCircleFilled /> : <CheckCircleOutlined />}>
                 영문주소
@@ -221,7 +228,7 @@ export const App = (props: Props) => {
         </Button>,
     ], [showEngAddr, showRoadAddr, showLegacyAddr, updatingSettings, handleSearchOptionClick]);
 
-    const handleScrollEvent = React.useCallback(() => {
+    const handleScrollEvent = useCallback(() => {
         const list = document.getElementsByClassName("address-list");
         const bottom = list[0]?.getBoundingClientRect().bottom ?? 0;
         if (bottom > 0 && bottom <= window.innerHeight) {
@@ -230,11 +237,11 @@ export const App = (props: Props) => {
         }
     }, [loadNextAddress]);
 
-    React.useEffect(() => {
+    useEffect(() => {
         if (getRuntime() === "extension") {
             settings?.once("ready", () => {
                 console.log("Settings loaded", settings);
-                const searchResult = settings?.settings?.searchResult;
+                const searchResult = settings.settings?.searchResult;
                 setShowEngAddr(searchResult?.showEng ?? false);
                 setShowRoadAddr(searchResult?.showRoad ?? true);
                 setShowLegacyAddr(searchResult?.showLegacy ?? true);
@@ -247,7 +254,7 @@ export const App = (props: Props) => {
         }
     }, [settings]);
 
-    React.useEffect(() => {
+    useEffect(() => {
         document.addEventListener("scroll", handleScrollEvent);
         return () => {
             document.removeEventListener("scroll", handleScrollEvent);
@@ -263,7 +270,7 @@ export const App = (props: Props) => {
                         enterButton allowClear
                         placeholder="검색할 주소 입력"
                         value={searchValue}
-                        loading={showLoading}
+                        loading={loading}
                         onChange={handleSearchValueChange}
                         onSearch={handleSearchClick} />
                 </SearchWrapper>
@@ -275,7 +282,7 @@ export const App = (props: Props) => {
                     showEngAddr={showEngAddr}
                     showRoadAddr={showRoadAddr}
                     showLegacyAddr={showLegacyAddr} />
-                {showLoading ? (
+                {loading ? (
                     <Spinner />
                 ) : isEnd ? (
                     <ListEnd>
diff --git a/src/components/AddressList/index.tsx b/src/components/AddressList/index.tsx
index 630c916..9f8acba 100644
--- a/src/components/AddressList/index.tsx
+++ b/src/components/AddressList/index.tsx
@@ -1,11 +1,18 @@
 /* eslint-disable jsx-a11y/accessible-emoji */
+/**
+ * External modules
+ */
 import React from "react";
 import styled from "styled-components";
 import { Collapse, Typography } from "antd";
+
+/**
+ * Internal modules
+ */
+import "./AddressList.css";
 import { AddressData } from "../../AddressManager";
 import { ClickToCopyText } from "../ClickToCopyText";
 import { FeedbackPopover } from "../FeedbackPopover";
-import "./AddressList.css";
 
 interface Props {
     data: AddressData[];
@@ -27,6 +34,7 @@ const EmptyText = styled(Typography.Paragraph)`
 
 export const AddressList = (props: Props) => {
     const { data, showEngAddr, showRoadAddr, showLegacyAddr } = props;
+
     if (!data || !data.length) {
         return <EmptyText type="secondary">
             검색 결과가 없습니다.<br />
@@ -34,6 +42,7 @@ export const AddressList = (props: Props) => {
             <FeedbackPopover />
         </EmptyText>;
     }
+
     return (
         <Collapse className="address-list" bordered={false} defaultActiveKey={[0]}>
             {data.map((row, i) => (
diff --git a/src/components/ClickToCopyText/index.tsx b/src/components/ClickToCopyText/index.tsx
index 935b2ac..2e37efb 100644
--- a/src/components/ClickToCopyText/index.tsx
+++ b/src/components/ClickToCopyText/index.tsx
@@ -1,9 +1,16 @@
-import React from "react";
+/**
+ * External modules
+ */
+import React, { useCallback, useState } from "react";
 import {
     Button,
     Tooltip,
 } from "antd";
 import copy from "copy-to-clipboard";
+
+/**
+ * Internal modules
+ */
 import "./ClickToCopyText.css";
 
 interface ClickToCopyTextProps {
@@ -11,20 +18,21 @@ interface ClickToCopyTextProps {
     analytics?: "우편번호" | "도로명주소" | "지번주소" | "영문주소";
 }
 
-export const ClickToCopyText: React.FC<ClickToCopyTextProps> = ({ children, analytics }: ClickToCopyTextProps) => {
-    const [copied, setCopied] = React.useState(false);
+export const ClickToCopyText = (props: ClickToCopyTextProps) => {
+    const { children, analytics } = props;
+    const [copied, setCopied] = useState(false);
 
-    const handleCopyClick = React.useCallback(() => {
+    const handleCopyClick = useCallback(() => {
         setCopied(true);
         copy(children);
         window.ga("send", "event", "address", "copy", `${analytics} 복사`);
-    }, [setCopied, analytics, children]);
+    }, [analytics, children]);
 
-    const handleVisibleChange = React.useCallback((visible: boolean) => {
+    const handleVisibleChange = useCallback((visible: boolean) => {
         if (!visible) {
             setTimeout(() => setCopied(false), 100);
         }
-    }, [setCopied]);
+    }, []);
     return (
         <Tooltip title={!copied ? "클릭해서 복사하기" : "복사완료!"} onVisibleChange={handleVisibleChange}>
             <Button className="text-click-to-copy" type="link" onClick={handleCopyClick}>{children}</Button>
diff --git a/src/components/FeedbackPopover.tsx b/src/components/FeedbackPopover.tsx
index b368a1e..0db2c14 100644
--- a/src/components/FeedbackPopover.tsx
+++ b/src/components/FeedbackPopover.tsx
@@ -1,5 +1,8 @@
 /* eslint-disable jsx-a11y/accessible-emoji */
-import React from "react";
+/**
+ * External modules
+ */
+import React, { useCallback, useState } from "react";
 import styled from "styled-components";
 import { Button, Input, Popover, Typography } from "antd";
 import axios from "axios";
@@ -31,12 +34,12 @@ const PopoverContentStyle = {
 };
 
 const FeedbackForm = () => {
-    const [message, setMessage] = React.useState("");
-    const [sending, setSending] = React.useState(false);
-    const [sent, setSent] = React.useState(false);
+    const [message, setMessage] = useState("");
+    const [sending, setSending] = useState(false);
+    const [sent, setSent] = useState(false);
 
-    const handleSendClick = React.useCallback(async () => {
-        if (sent) {
+    const handleSendClick = useCallback(async () => {
+        if (sent || !message) {
             return;
         }
         setSending(true);
@@ -48,14 +51,15 @@ const FeedbackForm = () => {
         } finally {
             setSending(false);
         }
-    }, [message, sent, setSent, setSending]);
+    }, [message, sent]);
+
     return <FeedbackSenderWrapper>
         <Input.TextArea disabled={sent || sending}
             value={message}
             rows={3}
             placeholder="이곳에 피드백 내용을 입력해주세요.&#10;작성해주신 소중한 피드백이 더 좋은 주소검색을 만들어요!"
             onChange={(ev) => setMessage(ev.target.value)} />
-        <Button disabled={sent || sending} type="primary" onClick={handleSendClick}>
+        <Button disabled={sent || sending || !message} type="primary" onClick={handleSendClick}>
             {!sent ? "보내기 🎉" : "피드백 전달 완료! 💛"}
         </Button>
     </FeedbackSenderWrapper>;
diff --git a/src/index.tsx b/src/index.tsx
index d28800a..f2573cf 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -1,10 +1,17 @@
+/**
+ * External modules
+ */
 import React from "react";
 import * as Sentry from "@sentry/react";
 import { render } from "react-dom";
+
+/**
+ * Internal modules
+ */
 import { App } from "./App";
-import { getRuntime, isProduction } from "./utils";
 import { AddressManager } from "./AddressManager";
 import { SettingsManager, Settings, DEFAULT_SETTINGS } from "./SettingsManager";
+import { getRuntime, isProduction } from "./utils";
 
 //  inject NODE_ENV variable into window object
 window.__ENV__ = {