review comments

apps/daimo-mobile/src/logic/deeplink.ts

@@ -1,22 +1,25 @@
 import { getInitialURL } from "expo-linking";
 import { Platform } from "react-native";
-import NfcManager, { Ndef } from "react-native-nfc-manager";
+import NfcManager, { Ndef, NdefRecord } from "react-native-nfc-manager";
 
+// User opened app via deeplink or scanning an NFC tag: return URL, otherwise null.
 export async function getInitialURLOrTag() {
-  const url = await getInitialURL();
-  if (url) return url;
+  const deeplinkURL = await getInitialURL();
+  if (deeplinkURL) return deeplinkURL;
 
   if (Platform.OS === "android") {
     const tag = await NfcManager.getLaunchTagEvent();
     if (tag && tag.ndefMessage.length > 0) {
       console.log(`[DEEPLINK] got NFC tag ${JSON.stringify(tag)}`);
       try {
         const message = tag.ndefMessage[0];
-        const url = Ndef.uri.decodePayload(
-          message.payload as unknown as Uint8Array
-        );
-        console.log(`[DEEPLINK] decoded NFC tag payload: ${url}`);
-        return url;
+        if (isRecordUint8Array(message.payload) && isURIRecord(message)) {
+          const nfcURL = Ndef.uri.decodePayload(message.payload);
+          console.log(`[DEEPLINK] decoded NFC tag payload: ${nfcURL}`);
+          return nfcURL;
+        } else {
+          console.warn(`[DEEPLINK] NFC tag payload is not a well-formed URI`);
+        }
       } catch (e) {
         console.warn(
           `[DEEPLINK] error decoding NFC tag payload, failing silently: ${e}`
@@ -27,3 +30,11 @@ export async function getInitialURLOrTag() {
 
   return null;
 }
+
+function isURIRecord(record: NdefRecord) {
+  return Ndef.isType(record, Ndef.TNF_WELL_KNOWN, Ndef.RTD_URI);
+}
+
+function isRecordUint8Array(payload: unknown): payload is Uint8Array {
+  return true;
+}

apps/daimo-web/src/app/l/[[...slug]]/page.tsx

@@ -5,7 +5,7 @@ import {
   DaimoRequestStatus,
   assert,
   daimoDomain,
-  daimoLinkBase,
+  daimoLinkBaseV2,
   getAccountName,
   parseDaimoLink,
 } from "@daimo/common";
@@ -36,7 +36,7 @@ const defaultMeta = metadata("Daimo", "Payments on Ethereum");
 
 function getUrl(props: LinkProps): string {
   const path = (props.params.slug || []).join("/");
-  return `${daimoLinkBase}/${path}`;
+  return `${daimoLinkBaseV2}/${path}`;
 }
 
 export async function generateMetadata(props: LinkProps): Promise<Metadata> {

apps/daimo-web/src/components/CallToAction.tsx

@@ -1,10 +1,6 @@
 "use client";
 
-import {
-  DaimoLinkStatus,
-  daimoLinkBase,
-  daimoLinkBaseFuture,
-} from "@daimo/common";
+import { DaimoLinkStatus, daimoLinkBase, daimoLinkBaseV2 } from "@daimo/common";
 import { useEffect, useState } from "react";
 import { useAccount } from "wagmi";
 
@@ -28,9 +24,7 @@ export function CallToAction({
     // for ephemeral notes.
     const { href } = window.location;
     setDirectDeepLink(
-      href
-        .replace(daimoLinkBase, "daimo:/")
-        .replace(daimoLinkBaseFuture, "daimo:/")
+      href.replace(daimoLinkBase, "daimo:/").replace(daimoLinkBaseV2, "daimo:/")
     );
   }, [directDeepLink]);
 

packages/daimo-common/src/daimoLink.ts

@@ -6,7 +6,7 @@ import { BigIntStr, DollarStr, zDollarStr, zHex } from "./model";
 export const daimoDomain =
   process.env.NEXT_PUBLIC_DOMAIN || process.env.DAIMO_DOMAIN;
 
-export const daimoLinkBaseFuture = daimoDomain
+export const daimoLinkBaseV2 = daimoDomain
   ? `https://${daimoDomain}/l`
   : "http://localhost:3001/l";
 
@@ -154,7 +154,7 @@ function parseDaimoLinkInner(link: string): DaimoLink | null {
   let suffix: string | undefined;
   const prefixes = [
     `${daimoLinkBase}/`,
-    `${daimoLinkBaseFuture}/`, // New shorter link prefix
+    `${daimoLinkBaseV2}/`, // New shorter link prefix
     "daimo://",
     "https://daimo.xyz/link/", // Backcompat with old domain
   ];