Pass options to fetch

README.md

@@ -46,10 +46,12 @@ Fetch target site and scrape metadata. This function send multiple requests to d
 
 `suppressAdditionalRequest` option suppress this behavior. With `suppressAdditionalRequest`option, this function fetches only the specified URL and reduces processing time, but provides only information which can be extracted from the specified page.
 
+You can also pass the options for `fetch` function.
+
 ```ts
 type Options = {
   suppressAdditionalRequest?: boolean
-}
+} & RequestInit
 
 type ImageInfo = {
   src: string
@@ -65,3 +67,8 @@ type Metadata = {
   image: ImageInfo | undefined
 }
 ```
+
+```ts
+// example using fetch options
+fetchSiteMetadata('https://example.test', { headers: { 'User-Agent': 'bot' } })
+```

src/index.ts

@@ -61,19 +61,33 @@ const fetchImageInfo = async (info: ImageInfo) => {
   }
 }
 
-export type Options = {
+type IntrinsicOptions = {
   suppressAdditionalRequest?: boolean
 }
 
+export type Options = IntrinsicOptions & Parameters<typeof fetch>[1]
+
 export type {
   Metadata,
   ImageInfo
 }
 
+function fetchOptions(options: Options): RequestInit {
+  const res = {} as Record<string, any>
+  const optionKeys = ['suppressAdditionalRequest']
+  for (const [k, v] of Object.entries(options)) {
+    if (!optionKeys.includes(k)) {
+      res[k] = v
+    }
+  }
+  return res
+}
+
 export default async function fetchSiteMetadata(url: string | URL, options: Options = {}): Promise<Metadata> {
   const urlString = typeof url === 'string' ? url : url.toString()
   const controller = new AbortController()
   const response = await fetch(urlString, {
+    ...fetchOptions(options),
     signal: controller.signal
   })
   if (!response.body) { throw new Error('response.body') }

test/index.ts

@@ -13,6 +13,14 @@ const testServer = createServer(async (req, res) => {
     res.end('</div></html>')
     return
   }
+  if (req.url === '/header-test') {
+    if (req.headers['test'] === 'true') {
+      res.end('<title>title</title>')
+    } else {
+      res.end('<title>error</title>')
+    }
+    return
+  }
   try {
     const file = await readFile(join('./test/fixtures/', req.url))
     if (req.url.endsWith('.html')) {
@@ -141,6 +149,13 @@ test('Deprecated icon rel', async t => {
   t.is(res.icon, new URL('/favicon2.ico', url).toString());
 })
 
+test('Passing fetch options', async t => {
+  const res = await fetchSiteMetadata(new URL('/header-test', url), {
+    headers: { 'test': 'true' }
+  })
+  t.is(res.title, 'title')
+})
+
 test.after(() => {
   testServer.close()
   testServerWithoutFavicon.close()