ruby on rails - Stub set later on perform

i'm trying stub out activejob method in rspec cannot fiddle out. i'm having email send class mailchimp mailinglistunsubscribejob. call is:

mailinglistunsubscribejob.set(wait: 20.days).perform_later(subject: user, list: "activation")

usually in rspec when not having set(wait: 20.days) have perform_later following in specs:

allow(mailinglistunsubscribejob).to receive(:perform_later)

but not work. idea?

since using rspec already, can use rpec-activejob.

if job uses set(wait_until: time), can use .to_run_at(time) chain after enqueue_a call well.

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