Imported from sake92/regenesca (AGENTS.md). Install upstream with npx skills add sake92/regenesca. Copyright stays with the author.

AGENTS.md — Regenesca

Build system: Deder (NOT SBT)

• Install: brew install sake92/tap/deder
• Build config: deder.pkl (Pkl format)
• Scala version: 2.13.18 (compilation and runtime)

Commands

Architecture

• Package: ba.sake.regenesca
• Language: Scala 2.13 (Scala 2 source, not Scala 3)
• Dependencies: Scalameta (AST), Scalafix-core 0.14.2 (patch-based rewriting)

Key types

• RegenescaGenerator — top-level orchestrator. Takes SourceMerger, calls generate(Seq[GeneratedFileSource])
• SourceMerger — the merge engine. Accepts mergeDefBodies: Boolean (default true) and ForComprehensionMergeStrategy (default PreserveUserExpressions)
• GeneratedFileSource(path: Path, source: Source) — pairs a file path with a Scalameta Source AST

How merging works

The merger builds Scalafix Patch operations (replace, add, addGlobalImport) and applies them via PatchInternals.tokenPatchApply to rewrite the original token stream. It is not string-based — it's structural/AST-level.

Merge rules:

• class/object/trait — merge member bodies recursively
• def — match by full signature; merge bodies (or overwrite if mergeDefBodies=false)
• val/var — match by name; overwrite
• enum/type — overwrite entirely
• given — match by composite key; overwrite
• import — add if not already present
• case branches — merge by pattern
• Expressions inside method bodies are preserved (not managed)
• User-added members not in generated source are left untouched

Tests

• Framework: MUnit 1.0.1 (org.scalameta::munit)
• Base class: BaseSuite extends munit.FunSuite, provides assertEqStructure(obtained: String, expected: Source)
• Tests use Scalameta quasiquotes (source"...") inline — no external fixture files
• assertEqStructure compares AST structure, not string equality (formatting differences are ignored)
• Idempotency is tested: merge(merge(first, generated), generated) == merge(first, generated)
• Test dialect is Scala34

Formatting

• Scalafmt 3.7.15, maxColumn = 120, runner.dialect = scala3
• Note: scalafmt dialect is scala3 but the project compiles as Scala 2.13

Release

VERSION="x.y.z"
git commit --allow-empty -am "Release $VERSION"
git tag -a $VERSION -m "Release $VERSION"
git push --atomic origin main $VERSION

Pushing a tag triggers .github/workflows/release.yml which runs CI tests then publishes to Sonatype (Maven Central).

CI

• .github/workflows/ci.yml — runs on push to main and PRs
• Installs deder via Homebrew, then deder exec -t compile and deder exec -t test
• continue-on-error: true is set (noted as temporary)