Clones a curated set of public (and optionally private) Rell projects and verifies that the local Rell build still compiles and runs the projects' own tests against them. Runs are long — the suite is not wired into the default CI pipeline; it ships as a manually-triggered job (pages:regression) and a collection of Gradle tasks for local use.

The default pipeline per project is chr install → chr build → chr test, all invoked against the locally-built chr (built from the Rell snapshot in this repo by the shared :performance:buildLocalChr task). Projects without a test: block in their chromia.yml override commands to drop the test step — otherwise chr test exits with "No tests to run".

Parallelism is owned by JUnit Jupiter. A @TestFactory (test/regression/RegressionTest.kt) emits one DynamicTest per (project, backend) pair; all units fan out concurrently inside one test JVM (capped by -PregressionParallelism, default 4 locally / 8 in CI). Each unit operates on its own working copy under workdir/<project>-<backend>/, mirrored from the master clone (workdir/<project>/) by refreshBackendCopy in src/regression/compile.kt, so the two backends of one project can run in parallel without chr install racing on the shared src/lib/<name> clone tree. chr itself runs out-of-process via ProcessBuilder — its ~2.5 GB JVM lives in the OS, not in the test JVM. Each unit also leases its own throw-away PostgreSQL spun up via Testcontainers (withProjectPostgres in src/regression/compile.kt). Each unit gets a fresh database, so suites never see leftover state from a sibling run. Requires a reachable Docker daemon: locally pick it up from DOCKER_HOST / local.properties; in CI the .gitlab-ci.yml variables already point at the DIND service.

# End-to-end: build chr, clone every project, compile + test each, render the HTML.
./gradlew :regression:regression

# Just one project, both backends (handy while debugging a single regression):
./gradlew :regression:regression --tests "ft4-lib*"

# Just one (project, backend):
./gradlew :regression:regression --tests "ft4-lib [interpreter]"

# Public-only flavour (what CI runs; never touches private.json):
./gradlew :regression:regressionPublic

# Individual steps also exist:
./gradlew :performance:buildLocalChr       # build the local chr binary (shared across the repo)
./gradlew :regression:regressionClone      # clone (or pull) every repo into regression/workdir
./gradlew :regression:regressionReport     # merge reports/parts/*.json -> results.json -> report.html

Each project run writes a result fragment under regression/reports/parts/; regressionReport (wired as a finalizedBy of every Test task) merges them into results.json and renders the HTML. ignoreFailures = true on the Test task means a failing project surfaces in the HTML but doesn't fail the build — the report is the verdict.

Reports land in regression/reports/report.html.

The toolkit reads two JSON files in this directory:

• public.json — tracked. Open-source Rell projects: ft4-lib, postchain-eif, etc.
• private.json — gitignored. Copy private.json.example, fill in the URLs you have access to.

Each entry:

{
  "name": "ft4-lib",                              // workdir directory + report row label
  "url": "https://gitlab.com/chromaway/ft4-lib",  // git clone URL
  "ref": "development",                           // optional; default = repository default branch
  "rellPath": ".",                                // dir containing chromia.yml, relative to repo root
  "commands": [["install"], ["build"], ["test"]], // chr invocations run sequentially from rellPath;
                                                  // non-zero exit short-circuits.
                                                  // Default: [["install"], ["build"], ["test"]].
                                                  // Drop ["test"] for projects without a test: block.
  "expectedFailure": false,                       // ok to fail; reported as "expected fail"
  "notes": "Reference Chromia FT4 token-fungibles library."
}