refactor: 改用 TypeScript。close #1.

lib/utils/files.ts

@@ -11,13 +11,13 @@ const flattenArray = (input) =>
 
 const map = (fn) => (input) => input.map(fn)
 
-const walkDir = (fullPath) => {
+const walkDir = (fullPath: string) => {
   return fs.statSync(fullPath).isFile() ? fullPath : getAllFilesRecursively(fullPath)
 }
 
-const pathJoinPrefix = (prefix) => (extraPath) => path.join(prefix, extraPath)
+const pathJoinPrefix = (prefix: string) => (extraPath: string) => path.join(prefix, extraPath)
 
-const getAllFilesRecursively = (folder) =>
+const getAllFilesRecursively = (folder: string): string[] =>
   pipe(fs.readdirSync, map(pipe(pathJoinPrefix(folder), walkDir)), flattenArray)(folder)
 
 export default getAllFilesRecursively

lib/utils/formatDate.ts

@@ -1,7 +1,7 @@
 import siteMetadata from '@/data/siteMetadata'
 
-const formatDate = (date) => {
-  const options = {
+const formatDate = (date: string) => {
+  const options: Intl.DateTimeFormatOptions = {
     year: 'numeric',
     month: 'long',
     day: 'numeric',

lib/utils/htmlEscaper.ts

@@ -1,7 +1,6 @@
 const { replace } = ''
 
 // escape
-const es = /&(?:amp|#38|lt|#60|gt|#62|apos|#39|quot|#34);/g
 const ca = /[&<>'"]/g
 
 const esca = {
@@ -11,7 +10,7 @@ const esca = {
   "'": '&#39;',
   '"': '&quot;',
 }
-const pe = (m) => esca[m]
+const pe = (m: keyof typeof esca) => esca[m]
 
 /**
  * Safely escape HTML entities such as `&`, `<`, `>`, `"`, and `'`.
@@ -20,4 +19,4 @@ const pe = (m) => esca[m]
  *  the input type is unexpected, except for boolean and numbers,
  *  converted as string.
  */
-export const escape = (es) => replace.call(es, ca, pe)
+export const escape = (es: string): string => replace.call(es, ca, pe)

lib/utils/kebabCase.ts

@@ -1,5 +1,5 @@
 import { slug } from 'github-slugger'
 
-const kebabCase = (str) => slug(str)
+const kebabCase = (str: string) => slug(str)
 
 export default kebabCase