Integration Tests – Presto

End-to-end tests that drive the Presto platform operators (TableSource, Filter, Projection, Join) through the Wayang API against a live PrestoDB cluster.

Test	Module	Needs
`AllOperatorsIT`	`wayang-presto`	a local Presto (Docker)

The test skips (it does not fail) when Presto is unreachable.

Prerequisites

JDK 17 — required. The Scala in wayang-spark does not compile on JDK 21+, and the build targets release 17, so JDK 11 is too old. Point Maven at a JDK 17:
```
export JAVA_HOME=/path/to/jdk-17      # e.g. .../corretto-17.jdk/Contents/Home
```
Maven 3.8+
Docker

Common Maven flags

The repo's root build runs RAT + license + prerequisite checks that are noisy for local runs; skip them:

-Drat.skip=true -Dlicense.skip=true -Dmaven.javadoc.skip=true -Pskip-prerequisite-check

First build only: drop -o (offline) so Maven can download dependencies.

Presto

The test is self-contained: it creates and seeds its own memory.wayang_it tables in Presto's built-in in-memory connector (scaled to 120k rows so the optimizer elects SQL pushdown) and drops them afterwards — no Hive metastore or object storage required.

# 1. start a single PrestoDB node with the in-memory connector
cd presto-setup && docker compose up -d --wait && cd ..

# 2. run the operator tests (JDK 17)
JAVA_HOME=/path/to/jdk-17 \
mvn -o test -pl wayang-platforms/wayang-presto \
  -Dtest=AllOperatorsIT -Dsurefire.failIfNoSpecifiedTests=false \
  -Drat.skip=true -Dlicense.skip=true -Dmaven.javadoc.skip=true -Pskip-prerequisite-check

# 3. tear down when done
cd presto-setup && docker compose down -v && cd ..

Expected: Tests run: 4, Failures: 0, Errors: 0, Skipped: 0.

docker compose up -d --wait blocks on the container healthcheck, so Presto is query-ready when it returns. Presto listens on host port 8081 (container 8080).

Notes

Pushdown is cost-gated. On tiny tables Wayang's optimizer prefers a full scan + Java-side filter/projection, so pushdown only appears once a table is large enough (hence the test scales to 120k rows). Each test asserts both correct results and that the expected SQL reached Presto (system.runtime.queries).
Join. A JDBC join is verified through the operator's SQL-clause contract executed on Presto, not the high-level WayangContext API — the logical JoinOperator emits Tuple2<Record,Record>, which cannot connect to a Record sink before the SQL pushdown flattens it.
Trailing semicolons. Presto's SQL parser rejects a trailing ; in executeQuery, so this branch also carries the jdbc-template change that stops emitting one (shared with the other JDBC platforms; Postgres/SQLite tolerate its absence).