Install gems in devenv CI smoke test, cache them

The devenv smoke test ran make test-<gem> without installing gems first,
so rspec was missing on a clean runner. Add make install-<gem> steps and
cache .devenv/state/.bundle keyed on the Gemfile.lock/devenv.lock hashes
so native gems aren't recompiled every run. Document the one-time install
for contributors too.

Author: fidel

.github/workflows/devenv_setup_test.yml

@@ -36,12 +36,19 @@ jobs:
         name: railseventstore
         authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
     - run: nix profile install nixpkgs#devenv
+    - uses: actions/cache@v4
+      with:
+        path: ".devenv/state/.bundle"
+        key: "${{ runner.os }}-devenv-gems-${{ hashFiles('**/Gemfile.lock', 'devenv.lock') }}"
+        restore-keys: "${{ runner.os }}-devenv-gems-"
     - run: devenv up -d
     - run: for i in $(seq 1 60); do nc -z localhost 10018 && exit 0; sleep 2; done; exit 1
+    - run: devenv shell -- make install-ruby_event_store-active_record
     - run: devenv shell -- make test-ruby_event_store-active_record
       env:
         DATABASE_URL: postgres://postgres:secret@localhost:10018/rails_event_store
         DATA_TYPE: jsonb
+    - run: devenv shell -- make install-ruby_event_store
     - run: devenv shell -- make test-ruby_event_store
     - if: always()
       run: devenv processes down || true

railseventstore.org/docs/contributing/devenv_setup.md

@@ -54,11 +54,14 @@ copied from any CI matrix cell works verbatim:
 
 ## Running the suites
 
-Inside the devenv shell, use the regular `make` targets:
+Inside the devenv shell, install the gem's dependencies once, then use the regular
+`make` targets:
 
 ```
-make test-ruby_event_store                 # no database needed
-make test-ruby_event_store-active_record   # against Postgres 18 by default
+make install-ruby_event_store                  # bundle install for that gem
+make test-ruby_event_store                     # no database needed
+make install-ruby_event_store-active_record    # bundle install for that gem
+make test-ruby_event_store-active_record       # against Postgres 18 by default
 ```
 
 To reproduce a specific CI matrix cell, use `res-cell`, which maps a short database

support/ci/generate

@@ -335,6 +335,17 @@ class CI
       { "if" => "always()", "run" => "devenv processes down || true" }
     end
 
+    def cache_gems
+      {
+        "uses" => "actions/cache@v4",
+        "with" => {
+          "path" => ".devenv/state/.bundle",
+          "key" => "${{ runner.os }}-devenv-gems-${{ hashFiles('**/Gemfile.lock', 'devenv.lock') }}",
+          "restore-keys" => "${{ runner.os }}-devenv-gems-",
+        },
+      }
+    end
+
     def make_nix_shell(target, imports: ["redis.nix"])
       { "run" => <<~SHELL, "working-directory" => "${{ env.WORKING_DIRECTORY }}" }
         nix-shell --run "make #{target}" -E"
@@ -725,15 +736,18 @@ class CI
           setup_nix_flakes,
           setup_cachix,
           install_devenv,
+          cache_gems,
           devenv_up,
           wait_for_port(10018),
+          devenv_run("make install-ruby_event_store-active_record"),
           devenv_run(
             "make test-ruby_event_store-active_record",
             env: {
               "DATABASE_URL" => "postgres://postgres:secret@localhost:10018/rails_event_store",
               "DATA_TYPE" => "jsonb",
             },
           ),
+          devenv_run("make install-ruby_event_store"),
           devenv_run("make test-ruby_event_store"),
           devenv_down,
         ],