feat!: make AuthInfo.getFields return readonly

src/org/authInfo.ts

@@ -664,8 +664,10 @@ export class AuthInfo extends AsyncOptionalCreatable<AuthInfo.Options> {
    * Get the authorization fields.
    *
    * @param decrypt Decrypt the fields.
+   *
+   * Returns a ReadOnly object of the fields.  If you need to modify the fields, use AuthInfo.update()
    */
-  public getFields(decrypt?: boolean): AuthFields {
+  public getFields(decrypt?: boolean): Readonly<AuthFields> {
     return this.stateAggregator.orgs.get(this.username, decrypt) ?? {};
   }
 

src/org/user.ts

@@ -389,8 +389,7 @@ export class User extends AsyncCreatable<User.Options> {
     });
 
     // Update the auth info object with created user id.
-    const newUserAuthFields: AuthFields = newUserAuthInfo.getFields();
-    newUserAuthFields.userId = refreshTokenSecret.userId;
+    newUserAuthInfo.update({ userId: refreshTokenSecret.userId });
 
     // Make sure we can connect and if so save the auth info.
     await this.describeUserAndSave(newUserAuthInfo);

test/unit/org/authInfoTest.ts

@@ -1267,7 +1267,7 @@ describe('AuthInfo', () => {
       });
 
       // delete the client secret
-      delete authInfo.getFields().clientSecret;
+      authInfo.update({ clientSecret: undefined });
       const instanceUrl = testOrg.instanceUrl.replace('https://', '');
       expect(authInfo.getSfdxAuthUrl()).to.contain(`force://PlatformCLI::${testOrg.refreshToken}@${instanceUrl}`);
     });