feat(clerk-expo): Introduce support for LocalAuth with LocalCredentials

[panteliselef]

Description

This PR introduces a new hook API

import {
  useLocalCredentials,
} from "@clerk/clerk-expo";

const {
  hasCredentials, // boolean
  userOwnsCredentials, // boolean | null
  biometricType,  // "face-recognition" | "fingerprint" | null
  setCredentials, // ({ identifier?: string, password: string }) => void
  authenticate, // () => Promise<SignInResource>
  clearCredentials, // () => Promise<void>
} = useLocalCredentials();

Video of the new UX flow

RPReplay_Final1719504401.MP4

1.Example usage in a profile page

import { 
  useUser, 
  useClerk, 
  useLocalCredentials,
} from "@clerk/clerk-expo";

export default function Page() {
  const { user } = useUser();
  const { signOut } = useClerk();

  const {
    hasCredentials,
    clearCredentials,
  } = useLocalCredentials();

  return (
    <View>
      <Text>Settings, {user?.emailAddresses[0].emailAddress}</Text>
      <Button title="Sign out" onPress={() => signOut()} />
      {
        hasCredentials &&
        <Button title="Remove biometric credentials" onPress={() => clearCredentials()} />
      }
    </View>
  );
}

1.Example usage in a custom sign in flow

import {
  useSignIn,
  useLocalCredentials,
} from "@clerk/clerk-expo";
import { Link, Stack, useRouter } from "expo-router";
import {
  Text,
  TextInput,
  Button,
  View,
  TouchableOpacity,
  StyleSheet,
} from "react-native";
import React from "react";
import { SymbolView } from "expo-symbols";

export default function Page() {
  const { signIn, setActive, isLoaded } = useSignIn();
  const router = useRouter();

  const [emailAddress, setEmailAddress] = React.useState("");
  const [password, setPassword] = React.useState("");
  const { hasCredentials, setCredentials, authenticate, biometryType } =
    useLocalCredentials();

  const onSignInPress = React.useCallback(
    async (useLocal = false) => {
      if (!isLoaded) {
        return;
      }

      try {
        const signInAttempt =
          hasCredentials && useLocal
            ? await authenticate()
            : await signIn.create({
                identifier: emailAddress,
                password,
              });

        if (signInAttempt.status === "complete") {
          await setActive({ session: signInAttempt.createdSessionId });
          if (!(hasCredentials && useLocal)) {
            await setCredentials({
              identifier: emailAddress,
              password,
            })
          }

          // navigate away
        } else {
          // handle other statuses of sign in 
        }
      } catch (err: any) {
         // handle any other error
      }
    },
    [isLoaded, emailAddress, password]
  );

  return (
    <View>
      <TextInput
        value={emailAddress}
        onChangeText={(emailAddress) => setEmailAddress(emailAddress)}
      />
      <TextInput
        value={password}
        onChangeText={(password) => setPassword(password)}
      />
      <Button title="Sign In" onPress={() => onSignInPress()} />
      {hasCredentials && biometryType && (
        <TouchableOpacity
          onPress={() => onSignInPress(true)}
        >
          <SymbolView
            name={
              biometryType === "face-recognition" ? "faceid" : "touchid"
            }
            type="monochrome"
          />
        </TouchableOpacity>
      )}
    </View>
  );
}

Checklist

• npm test runs as expected.
• npm run build runs as expected.
• (If applicable) JSDoc comments have been added or updated for any package exports
• (If applicable) Documentation has been updated

Type of change

• 🐛 Bug fix
• 🌟 New feature
• 🔨 Breaking change
• 📖 Refactoring / dependency upgrade / documentation
• other:

[changeset-bot]

🦋 Changeset detected

Latest commit: 6b6308d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@clerk/clerk-expo	Minor

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Click here if you're a maintainer who wants to add another changeset to this PR

[panteliselef]

!snapshot

[clerk-cookie]

Hey @panteliselef - the snapshot version command generated the following package versions:

Package	Version
@clerk/clerk-expo	1.3.0-snapshot.ve946474
gatsby-plugin-clerk	5.0.0-beta.45

Tip: Use the snippet copy button below to quickly install the required packages.
@clerk/clerk-expo

npm i @clerk/[email protected] --save-exact

gatsby-plugin-clerk

npm i [email protected] --save-exact

[LauraBeatris]

❓If the device supports multiple authentication methods (fingerprint and facial recognition), are we prioritizing fingerprint here?

[panteliselef]

That's a very nice question, tbh my intention here was to have AuthenticationType.IRIS behave like face-recognition so i might need to reverse the logic, in order for iris/face have priority

[LauraBeatris]

💡Nit: Could we extract this interpolation to a separate function? Or perhaps type it, to avoid accidentally changing it or misspelling between individual variables.

[LauraBeatris]

❓Is the purpose of ignore to not re-fetch isEnrolledAsync?

[panteliselef]

So the intention is to avoid race conditions in a situation where the component gets unmounted but the promise resolves after the component is already unmounted.

[panteliselef]

!snapshot

[clerk-cookie]

Hey @panteliselef - the snapshot version command generated the following package versions:

Package	Version
@clerk/clerk-expo	2.1.0-snapshot.vff0337d

Tip: Use the snippet copy button below to quickly install the required packages.
@clerk/clerk-expo

npm i @clerk/[email protected] --save-exact

[octoper]

❓ Should we have something like isPlatformSupported in LocalCredentialsInitValues in order to be easier to check if the hook can be used on specific platforms like Web or a device that does not has any biometric support, as now it seems you will have to check if biometryType is null which is not so clear if you don't take a look at the code

[panteliselef]

For devices that do not support biometric, android and iOS fallback to PIN, and if a pin does not exist then biometricType will be null.

with biometricType you get the available authenticator and it is useful mostly for UI purposes. Displaying a Face ID or a touch ID icon for example.

Maybe simply changing the name to supportedBiometricType would do ?

We don't wanna indicate that the device can use biometric, but instead if we can use local authentication (biometric or not) in order to store credentials.

[octoper]

I was mostly referring for platforms that this will not work at all like web,the biometric support was just an example as I didn't know if this fallbacks to pin

[brkalow]

Need some JSDoc comments on exported methods, and left a few non-blocking comments. Nice work!

Feel free to dismiss if you address the comments during your day tomorrow.

[brkalow]

💡 It would be nice to (optionally?) set the credentials after a successful auth

[octoper]

💯