stepper fails for unbound id in test position of check-expect

[jbclements]

To reproduce:

1. Set language level to Beginner
2. put this program in defns window:

(check-expect (f (list 4)) (list 4 13)) (check-expect (f (list 4)) (list 7 13))

Click Step.

See this error:

recon-source: no matching clause for syntax: (quote-syntax f)

Looks like in this case the reconstructed source contains a quote-syntax.

This bug has been present since at least Racket 7.4.

[shhyou]

The test engine recently fixed the source location of syntax errors in check-expects (#152). Is it related or is the bug exposed by that?

[jbclements]

perhaps indirectly. I think the issue here is that the reconstructor is just blindsided by the appearance of a quote-syntax, which suggests that it has to do with the expansion of the test forms. Could be related, though. Programming is complicated....

[mikesperber]

perhaps indirectly. I think the issue here is that the reconstructor is just blindsided by the appearance of a quote-syntax, which suggests that it has to do with the expansion of the test forms.

The expansion of tests forms certainly did change, but there's no (obvious) quote-syntax sitting there. (And the macros stepper refuses to work in the presence of undefined variables, AFAICS.)

The relevant macro is here, if that helps:

https://github.com/racket/htdp/blob/fc6c2c264179b14fa6cb9ecb1ccdfd69df03a757/htdp-lib/test-engine/syntax.rkt#L29