scalus

Marker for per-platform interop surface traits.

Java/JS-facing members that would degrade the Scala API live in per-platform traits mixed into the shared (or platform) type; every such trait extends this marker so the interop surface is mechanically enumerable by tests.

See docs/superpowers/specs/2026-07-11-cross-language-interop-style-guide-design.md.

Selects test baselines that legitimately differ between Scala compiler versions.

Budgets and compiled-script sizes shift between Scala 3.3.x (LTS) and 3.8.x because the host compiler desugars some constructs more leanly since 3.8.x — e.g. a tuple-datum pattern match no longer destructures-then-reconstructs the tuple, so the Scalus plugin sees a smaller tree. These differences are correctness-neutral (the contracts evaluate identically); only the exact budget/size numbers change. The 3.3.x LTS keeps the older, larger baselines; 3.8.x and the next LTS (which inherits the leaner desugaring) use the smaller ones.

Lives in scalus-testkit (not the example test sources) so that standalone projects ejected via eject-examples — which bundle the example tests but depend only on published artifacts — can still resolve scalus.ScalaCompilerVersion.

The active compiler version is injected by build.sbt (-Dscalus.test.scalaVersion). It can't be read from scala.util.Properties.versionNumberString, which reports the 2.13 standard-library version (2.13.x) on the Scala 3.3 LTS rather than the compiler version. When the property is absent (e.g. an ejected project, which pins the 3.3.x LTS) it defaults to "3.3.7".