[Bug]: Play function `mount` destructuring only works inline

[ghengeveld]

Describe the bug

In order to detect whether mount is used in a play function, we currently rely on the play function context arg to be destructured in-place (as function args). This requires SWC's bugfixes option to be set, otherwise the destructuring would be moved to the function body where our detection doesn't work.

Reproduction link

Reproduction steps

No response

System

-

Additional context

No response

[dosubot]

Storybook detects usage of mount in play functions by parsing the function's source and looking for inline destructuring of the context argument (e.g., async ({ mount }) => { ... }). If destructuring is moved to the function body—such as when SWC is used without the bugfixes option—Storybook cannot detect mount and will throw a MountMustBeDestructuredError if you try to use it in the play function body. This is a limitation of the current detection logic, which only inspects the function signature, not the body.

To ensure detection works, you must:

• Destructure mount inline in the play function's parameter list.
• Configure your builder to transpile to ES2017 or newer, so destructuring and async/await are preserved in the function signature.

There are no official workarounds or plans documented to support destructuring in the function body or to improve detection for this case. For more details, see the interaction testing docs and the relevant code.

If you have a specific reproduction or setup where this is causing issues, please share a minimal example to help investigate further.

To reply, just mention @dosu.

---

^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}