feat: add handle side effect function to authinfo

@W-0@

Author: peternhale

src/exported.ts

@@ -32,7 +32,7 @@ export {
 
 export { ConfigInfo, ConfigAggregator } from './config/configAggregator';
 
-export { AuthFields, AuthInfo, OrgAuthorization } from './org/authInfo';
+export { AuthFields, AuthInfo, AuthSideEffects, OrgAuthorization } from './org/authInfo';
 
 export { AuthRemover } from './org/authRemover';
 

src/org/authInfo.ts

@@ -113,6 +113,12 @@ export interface AccessTokenOptions {
   instanceUrl?: string;
 }
 
+export type AuthSideEffects = {
+  alias: string;
+  setDefault: boolean;
+  setDefaultDevHub: boolean;
+};
+
 type UserInfo = AnyJson & {
   username: string;
   organizationId: string;
@@ -563,6 +569,20 @@ export class AuthInfo extends AsyncOptionalCreatable<AuthInfo.Options> {
     return sfdxAuthUrl;
   }
 
+  /**
+   * Convenience function to handle typical side effects encountered when dealing with an AuthInfo.
+   * Given the values supplied in parameter sideEffects, this functions will set auth alias, default auth
+   * and default dev hub.
+   *
+   * @param sideEffects - instance of AuthSideEffects
+   */
+  public async handleSideEffects(sideEffects: AuthSideEffects): Promise<void> {
+    if (sideEffects.alias) await this.setAlias(sideEffects.alias);
+    if (sideEffects.setDefault) await this.setAsDefault({ org: true });
+    if (sideEffects.setDefaultDevHub) await this.setAsDefault({ devHub: true });
+    await this.save();
+  }
+
   /**
    * Set the target-env (default) or the target-dev-hub to the alias if
    * it exists otherwise to the username. Method will try to set the local