`Expect` macros don't work with string interpolation in Scala 2.13.14

[aragutskiy]

After updating Scala from 2.13.13 to 2.13.14 I got compilation error: "possible missing interpolator: detected an interpolated expression".

Doesn't work:

val world = "World"
assert(s"Hello, $world!".contains("Hell"))

Works:

val world = "World"
val assertion = s"Hello, $world!".contains("Hell")
assert(assertion)

[SethTisue]

Curious what happened here — what Scala change was responsible. cc @lrytz @som-snytt

[som-snytt]

Probably the same as etorreborre/specs2#1237
or explanation on the forum
https://users.scala-lang.org/t/regression-with-macro-and-interpolation-linting/9986/2?u=som-snytt

where -Wmacros:after (or -Wmacros:both) enables linting (for this particular lint) the tree after expansion.

Note that the new default -Wmacros:default was improved to make it less likely that -Wmacros:after is intended.

(-Wmacros:none turns off linting of trees that are transformed by macros, either before or after expansion.)

@SethTisue It ought to be mentioned in the release notes. It affects only those warning expanded trees, but that may not be a niche of the community.

[som-snytt]

I submitted a provisional PR with expecty, which I assume is used here. That would pass the lint irrespective of other settings.

[SethTisue]

It ought to be mentioned in the release notes

ah, indeed, https://github.com/scala/scala/releases/tag/v2.13.14 references scala/scala#10693

and the expecty PR Som mentions is eed3si9n/expecty#161