diff --git a/.node-version b/.node-version
new file mode 100644
index 0000000..6b17d22
--- /dev/null
+++ b/.node-version
@@ -0,0 +1 @@
+14.16.1
diff --git a/.prettierrc b/.prettierrc
index 59639c5..95bf7f6 100644
--- a/.prettierrc
+++ b/.prettierrc
@@ -1,5 +1,6 @@
 {
   "semi": false,
   "arrowParens": "always",
-  "singleQuote": true
+  "singleQuote": true,
+  "trailingComma": "none"
 }
diff --git a/package.json b/package.json
index 42c9256..2c155f7 100644
--- a/package.json
+++ b/package.json
@@ -1,13 +1,13 @@
 {
   "name": "kindle-booklog-sync",
   "version": "1.0.0",
-  "main": "Code.ts",
+  "main": "main.ts",
   "repository": "github.com/ysmtegsr/kindle-booklog-sync",
-  "author": "@ysmtegsr",
+  "author": "@ega4432",
   "license": "MIT",
   "private": true,
   "scripts": {
-    "lint": "npx eslint ./**/*.ts",
+    "lint": "eslint ./src/**/*.ts",
     "push": "clasp push",
     "watch": "clasp push --watch"
   },
diff --git a/src/main.ts b/src/main.ts
index cc725a6..b705dcd 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,19 +1,24 @@
+type Headers = {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  [key: string]: any
+}
+
 const booklogId: string = PropertiesService.getScriptProperties()
-  .getProperty('BOOKLOG_ID')
+  .getProperty('BOOKLOG_ID') || ""
 
 const booklogPassword: string = PropertiesService.getScriptProperties()
-  .getProperty('BOOKLOG_PASSWORD')
+  .getProperty('BOOKLOG_PASSWORD') || ""
 
-const logSheet: Sheet = SpreadsheetApp.getActiveSpreadsheet()
+const logSheet = SpreadsheetApp.getActiveSpreadsheet()
   .getSheetByName('log')
 
-const searchEmail = (): GmailThread[] => {
+const searchEmail = () => {
   return GmailApp.search("from:digital-no-reply@amazon.co.jp in:inbox")
 }
 
 const loginToBooklog = (): string[] => {
   const url = 'https://booklog.jp/login'
-  const res = UrlFetchApp.fetch(url, {
+  const params = {
     method: 'post',
     followRedirects: false,
     headers: { Referer: url },
@@ -21,30 +26,36 @@ const loginToBooklog = (): string[] => {
       account: booklogId,
       password: booklogPassword
     }
-  })
-
-  const headers = res.getAllHeaders()
+  } as GoogleAppsScript.URL_Fetch.URLFetchRequestOptions
+  const res = UrlFetchApp.fetch(url, params)
 
-  if (typeof headers['Set-Cookie'] === 'undefined') {
-    return []
-  }
+  const headers = res.getAllHeaders() as Headers
 
-  const cookies = headers['Set-Cookie'] === 'string'
+  if ('Set-Cookie' in headers) {
+    const cookies = headers['Set-Cookie'] === 'string'
       ? [headers['Set-Cookie']]
       : headers['Set-Cookie']
 
-  for (let i = 0; i < cookies.length; i++) {
-    cookies[i] = cookies[i].split(';')[0]
-  }
+    for (let i = 0; i < cookies.length; i++) {
+      cookies[i] = cookies[i].split(';')[0]
+    }
 
-  return cookies
+    return cookies
+    return []
+  } else {
+    return []
+  }
 }
 
-const getAsinList = (thread: GmailThread): string[] => {
+const getAsinList = (thread: GoogleAppsScript.Gmail.GmailThread): string[] => {
   const asinList = thread.getMessages()[0]
     .getBody()
     .match(/dp%2F.{10}/g)
 
+  if (!asinList) {
+    return []
+  }
+
   for (let i = 0; i < asinList.length; i++) {
     asinList[i] = asinList[i].slice(-10)
   }
@@ -52,7 +63,7 @@ const getAsinList = (thread: GmailThread): string[] => {
   return asinList
 }
 
-const uploadBook = (cookies: string[], asinList: string[]): HTTPResponse => {
+const uploadBook = (cookies: string[], asinList: string[]): GoogleAppsScript.URL_Fetch.HTTPResponse => {
   const url = 'https://booklog.jp/input'
 
   return UrlFetchApp.fetch(url, {
@@ -70,7 +81,9 @@ const uploadBook = (cookies: string[], asinList: string[]): HTTPResponse => {
 }
 
 const log = (asin: string, text: string): void => {
-  logSheet.appendRow([new Date(), asin, text])
+  if (logSheet && text) {
+    logSheet.appendRow([new Date(), asin, text])
+  }
 }
 
 export const main = (): void => {
@@ -88,7 +101,7 @@ export const main = (): void => {
     return
   }
 
-  threads.forEach((thread: GmailThread) => {
+  threads.forEach((thread: GoogleAppsScript.Gmail.GmailThread): void => {
     const asinList = getAsinList(thread)
     if (typeof asinList !== 'undefined') {
       Logger.log('asin is: ' + asinList.join(', '))
@@ -97,9 +110,14 @@ export const main = (): void => {
       const results = res.getContentText()
         .match(/.*tc(?:pink|blue) t10M.*/g)
 
-      results.forEach((result: string) => {
-        log(asinList.join(', '), result.match(/>(.*)</)[1])
-      })
+      if (results) {
+        results.forEach((result: string) => {
+          const text = result.match(/>(.*)</)
+          if (text) {
+            log(asinList.join(', '), text[1])
+          }
+        })
+      }
 
       thread.markRead().moveToArchive()
     } else {
diff --git a/src/util/types.ts b/src/util/types.ts
deleted file mode 100644
index 8502f73..0000000
--- a/src/util/types.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-export interface GmailApp {
-  search(query: string): GmailThread[]
-}
-
-export interface UrlFetchApp {
-  fetch(url: string, params: RequestParam): HTTPResponse
-}
-
-export interface RequestParam {
-  method: string
-  followRedirects: boolean
-  headers: {
-    Referer: string
-    Cookie?: string
-  }
-  payload: LoginPayload | UploadPayload
-}
-
-export interface LoginPayload {
-  account: string
-  password: string
-}
-
-export interface UploadPayload {
-  isbns: string
-  category_id: number
-  status: number
-}