name: Cache invalidation

# The regression suite, run on a PostgreSQL built with --enable-cassert and
# debug_discard_caches=1: every cache lookup meets an invalidation, the way
# PostgreSQL's own buildfarm hunts invalidation bugs.  This is what would have
# caught the 0.5.0 bug (run() re-resolved its row types by name after a cache
# flush) before release, and it guards every function against that class from
# now on -- see test/sql/recorded_path.sql.
#
# Packaged PostgreSQL cannot set debug_discard_caches, so the server is built
# from source (ci/build_cassert.sh).  That is slow, so this runs weekly and on
# demand, not on every push -- the per-push matrix in ci.yml covers the rest.
#
# Two branches: the current stable, and master (PostgreSQL 20 in development),
# so a change in PostgreSQL that breaks this extension shows up here in days.

on:
  schedule:
    - cron: "17 6 * * 1"   # Mondays, 06:17 UTC
  workflow_dispatch:
  # Branches only: GitHub does not apply a paths filter to a tag push, so without this the
  # weekly build ran on every release tag.
  push:
    branches: ['**']
    paths:
      - "ci/build_cassert.sh"
      - "ci/discard_caches_check.sh"
      - ".github/workflows/cache-invalidation.yml"

jobs:
  discard:
    name: assert build, ${{ matrix.branch }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        branch: [REL_18_STABLE, master]
    steps:
      - name: Install build tools
        run: sudo apt-get update && sudo apt-get install -y build-essential bison flex
      - name: Check out the extension
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
      - name: Check out PostgreSQL ${{ matrix.branch }}
        # The GitHub mirror, retried: git.postgresql.org refused GitHub's runners intermittently
        # (exit 128 on the clone, for v0.5.4, v0.5.5, v0.5.8 and v0.5.9). Same commits.
        run: |
          for i in 1 2 3; do
            git clone --depth 1 --branch ${{ matrix.branch }} https://github.com/postgres/postgres.git "$RUNNER_TEMP/pg-src" && exit 0
            rm -rf "$RUNNER_TEMP/pg-src"; sleep $((i * 20))
          done
          exit 1
      - name: Build it with assertions
        run: bash ci/build_cassert.sh "$RUNNER_TEMP/pg-src" "$RUNNER_TEMP/pgc"
      - name: Regression suite with debug_discard_caches=1
        run: PG_CONFIG="$RUNNER_TEMP/pgc/bin/pg_config" bash ci/discard_caches_check.sh