diff --git a/components/reader-page/DrawerTOC.tsx b/components/reader-page/DrawerTOC.tsx
index 4910319..a7a67d5 100644
--- a/components/reader-page/DrawerTOC.tsx
+++ b/components/reader-page/DrawerTOC.tsx
@@ -1,7 +1,7 @@
 import { Sheet, SheetContent, SheetHeader, SheetTitle, SheetTrigger } from "@/components/ui/sheet";
 import { useActiveHeading } from "@/hooks/useActiveHeading";
 import useDrawerTOCState from "@/stores/useDrawerTOCState";
-import type { TTOCItem } from "@/types/toc.type";
+import type { TTOCItem } from "@/types/docs.type";
 import Link from "next/link";
 import { MdMenuBook } from "react-icons/md";
 import { twMerge } from "tailwind-merge";
diff --git a/components/reader-page/TOC.tsx b/components/reader-page/TOC.tsx
index 7e2e0af..14617b2 100644
--- a/components/reader-page/TOC.tsx
+++ b/components/reader-page/TOC.tsx
@@ -1,5 +1,5 @@
 import { useActiveHeading } from "@/hooks/useActiveHeading";
-import type { TTOCItem } from "@/types/toc.type";
+import type { TTOCItem } from "@/types/docs.type";
 import Link from "next/link";
 import { twMerge } from "tailwind-merge";
 
diff --git a/components/utils/PostList.tsx b/components/utils/PostList.tsx
index 735514d..2fa0d0e 100644
--- a/components/utils/PostList.tsx
+++ b/components/utils/PostList.tsx
@@ -1,5 +1,5 @@
 import { normalizeDate } from "@/lib/date";
-import type { TPostListItem } from "@/types/post-list";
+import type { TPostListItem } from "@/types/docs.type";
 import { nanoid } from "nanoid";
 import Link from "next/link";
 import { Badge } from "../ui/badge";
diff --git a/lib/post-process.ts b/lib/post-process.ts
index daaa62e..dab429a 100644
--- a/lib/post-process.ts
+++ b/lib/post-process.ts
@@ -1,25 +1,25 @@
 import fs from "fs";
 import path from "path";
 import { PostFilesDirectory } from "@/consts/consts";
-import type { TFrontmatter } from "@/types/frontmatter.type";
-import type { TPostListItem, TPostsByTag } from "@/types/post-list";
+import type { TPostFrontmatter } from "@/types/frontmatter.type";
+import type { TPostListItem, TPostsByTag } from "@/types/docs.type";
 import { serialize } from "next-mdx-remote/serialize";
 import { titleCase } from "title-case";
 import { isEmptyString, nullifyEmptyArray, nullifyEmptyString } from "./utils";
 
-async function extractFrontmatters(filepath: string): Promise<TFrontmatter> {
+async function extractFrontmatters(filepath: string): Promise<TPostFrontmatter> {
   const source = fs.readFileSync(filepath, "utf-8");
   const mdxSource = await serialize(source, {
     parseFrontmatter: true,
     mdxOptions: { format: "md" },
   });
-  const frontmatter = mdxSource.frontmatter as TFrontmatter;
+  const frontmatter = mdxSource.frontmatter as TPostFrontmatter;
 
   const normalizedTags = frontmatter.tags
     ?.filter((tagname) => !isEmptyString(tagname))
     .map((tagname) => tagname.toUpperCase());
 
-  const normalizedResult: TFrontmatter = {
+  const normalizedResult: TPostFrontmatter = {
     title: titleCase(frontmatter.title),
     subtitle: nullifyEmptyString(frontmatter.subtitle),
     coverURL: nullifyEmptyString(frontmatter.coverURL),
diff --git a/lib/toc.ts b/lib/toc.ts
index a031767..d1e6b4e 100644
--- a/lib/toc.ts
+++ b/lib/toc.ts
@@ -1,4 +1,4 @@
-import type { TTOCItem } from "@/types/toc.type";
+import type { TTOCItem } from "@/types/docs.type";
 import { JSDOM } from "jsdom";
 
 /**
diff --git a/lib/utils.ts b/lib/utils.ts
index 10a0afc..34f6a93 100644
--- a/lib/utils.ts
+++ b/lib/utils.ts
@@ -1,4 +1,3 @@
-import type { NonEmptyArray } from "@/types/utils.type";
 import { type ClassValue, clsx } from "clsx";
 import { twMerge } from "tailwind-merge";
 
@@ -84,11 +83,11 @@ export function isEmptyArray(value: any[] | null | undefined): boolean {
  * @param value - The array value to be nullified if empty.
  * @returns The nullified array if it is empty, otherwise returns the original array.
  */
-export function nullifyEmptyArray<T>(value: T[] | null | undefined): NonEmptyArray<T> | null {
+export function nullifyEmptyArray<T>(value: T[] | null | undefined): T[] | null {
   if (isEmptyArray(value)) {
     return null;
   }
-  return value as NonEmptyArray<T>;
+  return value!;
 }
 
 /**
diff --git a/pages/api/search/[keyword].ts b/pages/api/search/[keyword].ts
index 4681dc9..fcfb647 100644
--- a/pages/api/search/[keyword].ts
+++ b/pages/api/search/[keyword].ts
@@ -1,6 +1,6 @@
 import { SearchIndex } from "@/lib/search";
 import { isEmptyString } from "@/lib/utils";
-import type { TSearchResultItem } from "@/types/search-result";
+import type { TSearchResultItem } from "@/types/docs.type";
 import type { NextApiRequest, NextApiResponse } from "next";
 
 type ResponseData = TSearchResultItem[];
diff --git a/pages/blog/[id].tsx b/pages/blog/[id].tsx
index 0cf0591..843c3d5 100644
--- a/pages/blog/[id].tsx
+++ b/pages/blog/[id].tsx
@@ -13,9 +13,8 @@ import { Config } from "@/data/config";
 import { normalizeDate } from "@/lib/date";
 import { getPostFileContent, sortedPosts } from "@/lib/post-process";
 import { makeTOCTree } from "@/lib/toc";
-import type { TFrontmatter } from "@/types/frontmatter.type";
-import type { TPostListItem } from "@/types/post-list";
-import type { TTOCItem } from "@/types/toc.type";
+import type { TPostFrontmatter } from "@/types/frontmatter.type";
+import type { TPostListItem, TTOCItem } from "@/types/docs.type";
 import { nanoid } from "nanoid";
 import type { GetStaticPaths, GetStaticProps } from "next";
 import { MDXRemote, type MDXRemoteSerializeResult } from "next-mdx-remote";
@@ -36,7 +35,7 @@ import { titleCase } from "title-case";
 type ReaderPageProps = {
   compiledSource: MDXRemoteSerializeResult;
   tocList: TTOCItem[];
-  frontMatter: TFrontmatter;
+  frontMatter: TPostFrontmatter;
   postId: string;
   nextPostListItem: TPostListItem | null;
   prevPostListItem: TPostListItem | null;
@@ -205,7 +204,7 @@ export const getStaticProps: GetStaticProps<ReaderPageProps> = async (context) =
 
   const postIndexInAllPosts = sortedPosts.allPostList.findIndex((item) => item.id === postId);
 
-  const frontMatter: TFrontmatter = sortedPosts.allPostList[postIndexInAllPosts].frontMatter;
+  const frontMatter: TPostFrontmatter = sortedPosts.allPostList[postIndexInAllPosts].frontMatter;
 
   const nextPostListItem =
     postIndexInAllPosts !== sortedPosts.allPostList.length - 1
diff --git a/pages/index.tsx b/pages/index.tsx
index 29cc2e9..9de5ead 100644
--- a/pages/index.tsx
+++ b/pages/index.tsx
@@ -10,7 +10,7 @@ import { LatestPostCountInHomePage } from "@/consts/consts";
 import { Config } from "@/data/config";
 import { sortedPosts } from "@/lib/post-process";
 import { generateRSSFeed } from "@/lib/rss";
-import type { TPostListItem } from "@/types/post-list";
+import type { TPostListItem } from "@/types/docs.type";
 import type { GetStaticProps } from "next";
 import Link from "next/link";
 import { LuPenTool } from "react-icons/lu";
diff --git a/pages/posts/[[...slug]].tsx b/pages/posts/[[...slug]].tsx
index 9cad524..4219053 100644
--- a/pages/posts/[[...slug]].tsx
+++ b/pages/posts/[[...slug]].tsx
@@ -11,7 +11,7 @@ import { PostCountPerPagination } from "@/consts/consts";
 import { Config } from "@/data/config";
 import { sortedPosts } from "@/lib/post-process";
 import { isEmptyArray, paginateArray } from "@/lib/utils";
-import type { TPostListItem } from "@/types/post-list";
+import type { TPostListItem } from "@/types/docs.type";
 import { nanoid } from "nanoid";
 import type { GetStaticPaths, GetStaticProps } from "next";
 import Link from "next/link";
diff --git a/pages/search.tsx b/pages/search.tsx
index 469fc98..6a1b089 100644
--- a/pages/search.tsx
+++ b/pages/search.tsx
@@ -8,7 +8,7 @@ import { NavBar } from "@/components/utils/NavBar";
 import { SEO } from "@/components/utils/SEO";
 import { Config } from "@/data/config";
 import { isEmptyString } from "@/lib/utils";
-import type { TSearchResultItem } from "@/types/search-result";
+import type { TSearchResultItem } from "@/types/docs.type";
 import axios from "axios";
 import { isArray } from "lodash";
 import { nanoid } from "nanoid";
diff --git a/pages/tags/[...slug].tsx b/pages/tags/[...slug].tsx
index 81f9da0..09c8082 100644
--- a/pages/tags/[...slug].tsx
+++ b/pages/tags/[...slug].tsx
@@ -10,7 +10,7 @@ import { PostCountPerPagination } from "@/consts/consts";
 import { Config } from "@/data/config";
 import { sortedPosts } from "@/lib/post-process";
 import { paginateArray } from "@/lib/utils";
-import type { TPostListItem } from "@/types/post-list";
+import type { TPostListItem } from "@/types/docs.type";
 import type { GetStaticPaths, GetStaticProps } from "next";
 import Link from "next/link";
 import { useRouter } from "next/router";
diff --git a/scripts/newpost.ts b/scripts/newpost.ts
index 2ece3ff..9de023c 100644
--- a/scripts/newpost.ts
+++ b/scripts/newpost.ts
@@ -1,6 +1,7 @@
 import { PostFilesDirectory } from "@/consts/consts";
 import { getCurrentTime } from "@/lib/date";
 import { stringifyFrontmatter } from "@/lib/frontmatter";
+import type { TPostFrontmatter } from "@/types/frontmatter.type";
 import { type ChildProcessWithoutNullStreams, type SpawnSyncReturns, spawn, spawnSync } from "child_process";
 import colors from "colors";
 import fs from "fs";
@@ -103,7 +104,7 @@ inquirer.prompt<TAnswer>(questions).then((answers) => {
   const time = `${year}-${month}-${day}`;
 
   // Stringify the frontmatters
-  const stringifiedFrontmatter = stringifyFrontmatter({
+  const frontmatter: TPostFrontmatter = {
     title: title,
     subtitle: subtitle,
     summary: "",
@@ -114,7 +115,8 @@ inquirer.prompt<TAnswer>(questions).then((answers) => {
     noPrompt: noPrompt,
     allowShare: allowShare,
     closed: false,
-  });
+  };
+  const stringifiedFrontmatter = stringifyFrontmatter(frontmatter);
 
   // Output the new post file
   const postFileName = `${year}-${month}-${day}-${_.kebabCase(answers.inputTitle)}.md`;
diff --git a/types/docs.type.ts b/types/docs.type.ts
new file mode 100644
index 0000000..d636bf4
--- /dev/null
+++ b/types/docs.type.ts
@@ -0,0 +1,23 @@
+import type { TPostFrontmatter } from "./frontmatter.type";
+
+export type TPostListItem = {
+  id: string;
+  frontMatter: TPostFrontmatter;
+};
+
+export type TPostsByTag = {
+  [tagName: string]: TPostListItem[];
+};
+
+export type TSearchResultItem = {
+  id: string;
+  title: string;
+  summary: string | null;
+  tags: string[] | null;
+};
+
+export type TTOCItem = {
+  level: number;
+  title: string;
+  anchorId: string;
+};
diff --git a/types/frontmatter.type.ts b/types/frontmatter.type.ts
index 690df3d..308f5fa 100644
--- a/types/frontmatter.type.ts
+++ b/types/frontmatter.type.ts
@@ -1,9 +1,7 @@
-import type { NonEmptyArray } from "./utils.type";
-
-export type TFrontmatter = {
+export type TPostFrontmatter = {
   title: string;
   time: string;
-  tags: NonEmptyArray<string> | null;
+  tags: string[] | null;
   subtitle: string | null;
   summary: string | null;
   coverURL: string | null;
diff --git a/types/post-list.ts b/types/post-list.ts
deleted file mode 100644
index a774aa8..0000000
--- a/types/post-list.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-import type { TFrontmatter } from "./frontmatter.type";
-
-export type TPostListItem = {
-  id: string;
-  frontMatter: TFrontmatter;
-};
-
-export type TPostsByTag = {
-  [tagName: string]: TPostListItem[];
-};
diff --git a/types/search-result.ts b/types/search-result.ts
deleted file mode 100644
index e56e1e3..0000000
--- a/types/search-result.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-export type TSearchResultItem = {
-  id: string;
-  title: string;
-  summary: string | null;
-  tags: string[] | null;
-};
diff --git a/types/toc.type.ts b/types/toc.type.ts
deleted file mode 100644
index 6eb153e..0000000
--- a/types/toc.type.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-export type TTOCItem = {
-  level: number;
-  title: string;
-  anchorId: string;
-};
diff --git a/types/utils.type.ts b/types/utils.type.ts
deleted file mode 100644
index 5ae448c..0000000
--- a/types/utils.type.ts
+++ /dev/null
@@ -1 +0,0 @@
-export type NonEmptyArray<T> = [T, ...T[]];