The RSpec Rollback Boundary

The transaction that undoes your test data doesn't start where you think it does.

1 The safety net you were promised

the transaction everything your test does in here gets undone when the test ends 🧪 one test

config.use_transactional_fixtures = true wraps each test in a database transaction, then rolls it back. That's the theory.

2 But the box doesn't start where you'd guess

A describe block is just Ruby code that defines your tests. It runs once, up front, while RSpec is still figuring out what tests exist — before any test, and its transaction, has begun.

describe block loads no transaction yet first "it" example starts transaction opens here example ends rolled back

3 Same-looking code, two very different outcomes

describe "my tests" do FactoryBot.create(:plan) outside any "it" it "some test" do ... end INSERT runs before BEGIN → COMMIT, stays in the DB

Created in the describe block

Ruby evaluates this line while RSpec is still building the example list — no transaction has opened.

describe "my tests" do BEGIN / SAVEPOINT it "some test" do FactoryBot.create(:plan) ROLLBACK → gone after the test

Created inside "it" (or via let!)

This line only runs once the example itself is executing — already inside the open transaction.

let! looks like it lives in the describe block, but it's really a before hook in disguise: RSpec runs it at the start of each example, after the transaction has already opened. That's why let! data rolls back, but a bare line in describe does not.

4 The rule of thumb

Ask one question about any line that creates data: does it run while an example is executing, or before RSpec has even started one?

Rolls back

Code inside an it block, or reached via let/let!, since both only run once an example is under way.

Does not roll back

Code written directly in a describe block, run at load time, before the first example's transaction has opened.