Add helper to validate token URI

utils/isValidTokenUri.ts

@@ -0,0 +1,21 @@
+/* eslint-disable eslint-comments/disable-enable-pair */
+/* eslint-disable @typescript-eslint/no-unsafe-call */
+/* eslint-disable @typescript-eslint/no-unsafe-assignment */
+export const checkTokenUri = async (tokenUri: string) => {
+  const file = await fetch(tokenUri.replace('ipfs://', 'https://ipfs.io/ipfs/'))
+    .then((res) =>
+      res.json().catch((err: any) => {
+        throw Error(`Metadata file could not be parsed. Please check that it is valid JSON.`)
+      }),
+    )
+    .catch((err: any) => {
+      throw Error(`Unable to fetch metadata from ${tokenUri}`)
+    })
+
+  if (!file.image) {
+    throw Error('Token URI must contain an image URL.')
+  }
+  if (file.image && !file.image.startsWith('ipfs://')) {
+    throw Error('Metadata file: The corresponding value for image must be an IPFS URL.')
+  }
+}