feat: rewrite utils to typescript

src/utils.ts

@@ -0,0 +1,33 @@
+import { posix as path } from 'path'
+import { NuxtOptions } from '@nuxt/types'
+
+export function joinUrl (...args: string[]) {
+  return path.join(...args).replace(':/', '://')
+}
+
+export function isUrl (url: string) {
+  return url.indexOf('http') === 0 || url.indexOf('//') === 0
+}
+
+export function getRouteParams (options: NuxtOptions) {
+  // routerBase
+  const routerBase = options.router.base
+
+  // publicPath
+  let publicPath
+  if (isUrl(options.build.publicPath)) {
+    publicPath = options.build.publicPath
+  } else {
+    publicPath = joinUrl(routerBase, options.build.publicPath)
+  }
+
+  return {
+    routerBase,
+    publicPath
+  }
+}
+
+module.exports = {
+  joinUrl,
+  getRouteParams
+}