fix: improve mfa.enroll return types (#956)

## What kind of change does this PR introduce?

Bug fix for the TypeScript types.

## What is the current behavior?

- Fixes #955

## What is the new behavior?

Use [TypeScript's function
overloading](https://www.typescriptlang.org/docs/handbook/2/functions.html#function-overloads)
to return

- TOTP data when `mfa.enroll` was passed `factorType: 'totp'`,
- phone data when `mfa.enroll` was passed `factorType: 'phone'`.

This fixes a breaking change in the types in
b957c30.

## Additional context

This PR would also expose the new following types:

- `MFAEnrollTOTPParams`
- `MFAEnrollPhoneParams`
- `AuthMFAEnrollTOTPResponse`
- `AuthMFAEnrollPhoneResponse`
- `AuthMFAEnrollErrorResponse` (it might be better to roll this type in
with the other two).

It might be better to keep these types private, since once they're
exposed, you can't easily remove them again without creating a breaking
change.

src/GoTrueClient.ts

@@ -88,6 +88,11 @@ import type {
   LockFunc,
   UserIdentity,
   SignInAnonymouslyCredentials,
+  MFAEnrollTOTPParams,
+  AuthMFAEnrollTOTPResponse,
+  AuthMFAEnrollErrorResponse,
+  MFAEnrollPhoneParams,
+  AuthMFAEnrollPhoneResponse,
 } from './lib/types'
 
 polyfillGlobalThis() // Make "globalThis" available
@@ -2353,6 +2358,12 @@ export default class GoTrueClient {
   /**
    * {@see GoTrueMFAApi#enroll}
    */
+  private async _enroll(
+    params: MFAEnrollTOTPParams
+  ): Promise<AuthMFAEnrollTOTPResponse | AuthMFAEnrollErrorResponse>
+  private async _enroll(
+    params: MFAEnrollPhoneParams
+  ): Promise<AuthMFAEnrollPhoneResponse | AuthMFAEnrollErrorResponse>
   private async _enroll(params: MFAEnrollParams): Promise<AuthMFAEnrollResponse> {
     try {
       return await this._useSession(async (result) => {

src/lib/types.ts

@@ -800,23 +800,23 @@ export type GenerateLinkType =
   | 'email_change_current'
   | 'email_change_new'
 
-export type MFAEnrollParams =
-  | {
-      /** The type of factor being enrolled. */
-      factorType: 'totp'
-      /** Domain which the user is enrolled with. */
-      issuer?: string
-      /** Human readable name assigned to the factor. */
-      friendlyName?: string
-    }
-  | {
-      /** The type of factor being enrolled. */
-      factorType: 'phone'
-      /** Human readable name assigned to the factor. */
-      friendlyName?: string
-      /** Phone number associated with a factor. Number should conform to E.164 format */
-      phone: string
-    }
+export type MFAEnrollTOTPParams = {
+  /** The type of factor being enrolled. */
+  factorType: 'totp'
+  /** Domain which the user is enrolled with. */
+  issuer?: string
+  /** Human readable name assigned to the factor. */
+  friendlyName?: string
+}
+export type MFAEnrollPhoneParams = {
+  /** The type of factor being enrolled. */
+  factorType: 'phone'
+  /** Human readable name assigned to the factor. */
+  friendlyName?: string
+  /** Phone number associated with a factor. Number should conform to E.164 format */
+  phone: string
+}
+export type MFAEnrollParams = MFAEnrollTOTPParams | MFAEnrollPhoneParams
 
 export type MFAUnenrollParams = {
   /** ID of the factor being unenrolled. */
@@ -873,56 +873,59 @@ export type AuthMFAVerifyResponse =
       error: AuthError
     }
 
-export type AuthMFAEnrollResponse =
-  | {
-      data: {
-        /** ID of the factor that was just enrolled (in an unverified state). */
-        id: string
-
-        /** Type of MFA factor.*/
-        type: 'totp'
-
-        /** TOTP enrollment information. */
-        totp: {
-          /** Contains a QR code encoding the authenticator URI. You can
-           * convert it to a URL by prepending `data:image/svg+xml;utf-8,` to
-           * the value. Avoid logging this value to the console. */
-          qr_code: string
-
-          /** The TOTP secret (also encoded in the QR code). Show this secret
-           * in a password-style field to the user, in case they are unable to
-           * scan the QR code. Avoid logging this value to the console. */
-          secret: string
-
-          /** The authenticator URI encoded within the QR code, should you need
-           * to use it. Avoid loggin this value to the console. */
-          uri: string
-        }
-        /** Friendly name of the factor, useful for distinguishing between factors **/
-        friendly_name?: string
-      }
-      error: null
+export type AuthMFAEnrollTOTPResponse = {
+  data: {
+    /** ID of the factor that was just enrolled (in an unverified state). */
+    id: string
+
+    /** Type of MFA factor.*/
+    type: 'totp'
+
+    /** TOTP enrollment information. */
+    totp: {
+      /** Contains a QR code encoding the authenticator URI. You can
+       * convert it to a URL by prepending `data:image/svg+xml;utf-8,` to
+       * the value. Avoid logging this value to the console. */
+      qr_code: string
+
+      /** The TOTP secret (also encoded in the QR code). Show this secret
+       * in a password-style field to the user, in case they are unable to
+       * scan the QR code. Avoid logging this value to the console. */
+      secret: string
+
+      /** The authenticator URI encoded within the QR code, should you need
+       * to use it. Avoid loggin this value to the console. */
+      uri: string
     }
-  | {
-      data: {
-        /** ID of the factor that was just enrolled (in an unverified state). */
-        id: string
+    /** Friendly name of the factor, useful for distinguishing between factors **/
+    friendly_name?: string
+  }
+  error: null
+}
+export type AuthMFAEnrollPhoneResponse = {
+  data: {
+    /** ID of the factor that was just enrolled (in an unverified state). */
+    id: string
 
-        /** Type of MFA factor. */
-        type: 'phone'
+    /** Type of MFA factor. */
+    type: 'phone'
 
-        /** Friendly name of the factor, useful for distinguishing between factors **/
-        friendly_name?: string
+    /** Friendly name of the factor, useful for distinguishing between factors **/
+    friendly_name?: string
 
-        /** Phone number of the MFA factor in E.164 format. Used to send messages  */
-       phone: string
-      }
-      error: null
-    }
-  | {
-      data: null
-      error: AuthError
-    }
+    /** Phone number of the MFA factor in E.164 format. Used to send messages  */
+    phone: string
+  }
+  error: null
+}
+export type AuthMFAEnrollErrorResponse = {
+  data: null
+  error: AuthError
+}
+export type AuthMFAEnrollResponse =
+  | AuthMFAEnrollTOTPResponse
+  | AuthMFAEnrollPhoneResponse
+  | AuthMFAEnrollErrorResponse
 
 export type AuthMFAUnenrollResponse =
   | {
@@ -1007,6 +1010,12 @@ export interface GoTrueMFAApi {
    * Upon verifying a factor, all other sessions are logged out and the current session's authenticator level is promoted to `aal2`.
    *
    */
+  enroll(
+    params: MFAEnrollTOTPParams
+  ): Promise<AuthMFAEnrollTOTPResponse | AuthMFAEnrollErrorResponse>
+  enroll(
+    params: MFAEnrollPhoneParams
+  ): Promise<AuthMFAEnrollPhoneResponse | AuthMFAEnrollErrorResponse>
   enroll(params: MFAEnrollParams): Promise<AuthMFAEnrollResponse>
 
   /**

test/GoTrueClient.test.ts

@@ -904,6 +904,20 @@ describe('User management', () => {
   })
 })
 
+describe('MFA', () => {
+  test('enroll({factorType: "totp"}) returns totp', async () => {
+    const { data, error } = await authWithSession.mfa.enroll({
+      factorType: 'totp',
+    })
+
+    if (error) {
+      throw error
+    }
+
+    expect(data.totp.qr_code).not.toBeNull()
+  })
+})
+
 describe('GoTrueClient with storageisServer = true', () => {
   const originalWarn = console.warn
   let warnings: any[][] = []