use assert instead of new error

Author: ondrej-langr

packages/auth-provider-automerge-repo/src/AuthProvider.ts

@@ -211,9 +211,7 @@ export class AuthProvider extends EventEmitter<AuthProviderEvents> {
    * Creates a team and registers it with all of our sync servers.
    */
   public async createTeam(teamName: string) {
-    if (!this.#user) {
-      throw new Error('Cannot create team as user is missing on AuthProvider')
-    }
+    assert(this.#user, 'Cannot create team as user is missing on AuthProvider')
 
     const team = Auth.createTeam(teamName, {
       device: this.#device,

packages/auth/src/connection/getDeviceUserFromGraph.ts

@@ -43,9 +43,7 @@ export const getDeviceUserFromGraph = ({
   const userKeyring = select.keyring(state, { type: USER, name: userId }, starterKeys)
   const keys = getLatestGeneration(userKeyring)
 
-  if (!keys) {
-    throw new Error('Failed to get device user from graph as there are no keys for user keyring')
-  }
+  assert(keys, 'Failed to get device user from graph as there are no keys for user keyring')
 
   const user: UserWithSecrets = { userName, userId, keys }