test: add integration tests with seeded MySQL/Redis and response snapshots

.github/workflows/ci.yml

@@ -37,7 +37,7 @@ jobs:
         with:
           components: rustfmt
       - name: cargo fmt
-        run: cargo fmt --check
+        run: cargo fmt --all --check
 
   clippy:
     name: Clippy
@@ -50,13 +50,17 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - name: cargo clippy
         # --all-targets lints the test code as well.
-        run: cargo clippy --locked --all-targets -- -D warnings
+        run: cargo clippy --locked --workspace --all-targets -- -D warnings
 
   test:
     name: Test
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
+      - name: Start MySQL and Redis
+        # Started before the toolchain so the containers initialise meanwhile.
+        # test-utils connects with defaults that match compose.yaml.
+        run: docker compose up --detach --wait database redis
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@v2
       - uses: taiki-e/install-action@v2
@@ -65,10 +69,13 @@ jobs:
       - name: cargo nextest
         # insta detects CI and fails on any snapshot mismatch instead of
         # writing a new snapshot.
-        run: cargo nextest run --locked --all-targets
+        run: cargo nextest run --locked --workspace --all-targets
       - name: doctests
         # nextest does not run doctests.
-        run: cargo test --locked --doc
+        run: cargo test --locked --workspace --doc
+      - name: Service logs
+        if: failure()
+        run: docker compose logs database redis
 
   cargo-deny:
     name: cargo-deny check ${{ matrix.checks }}

Cargo.toml

@@ -26,5 +26,12 @@ icu_collator = "2.3.1"
 icu_locale_core = "2.3.0"
 
 [dev-dependencies]
-insta = "1.48.0"
+insta = { version = "1.48.0", features = ["json"] }
 proptest = "1.11.0"
+sha2 = "0.10.9"
+test-utils = { path = "test-utils" }
+
+# test-utils is a separate crate so integration tests share one harness; it
+# depends on this crate, which only uses it as a dev-dependency.
+[workspace]
+members = [".", "test-utils"]

compose.yaml

@@ -1,5 +1,8 @@
-version: '3'
-
+# Local services for development and for the integration tests.
+#
+# Images follow production (website_k8s: verseghy-website/mysql and
+# verseghy-website/backend2-redis). The integration tests connect to these
+# ports as root by default; see docs/testing.md.
 services:
   database:
     image: docker.io/mysql:8
@@ -8,8 +11,18 @@ services:
       - "MYSQL_USER=backend"
       - "MYSQL_PASSWORD=password"
       - "MYSQL_ROOT_PASSWORD=secret"
+    # Every integration test opens its own small connection pool, and many run
+    # in parallel.
+    command: ["--max-connections=500"]
     ports:
         - "33061:3306"
+    healthcheck:
+      # Ping over TCP: during first-time initialisation the image runs a
+      # temporary server without networking, which would answer a socket ping.
+      test: ["CMD", "mysqladmin", "ping", "--host=127.0.0.1", "--user=root", "--password=secret"]
+      interval: 2s
+      timeout: 5s
+      retries: 60
   redis:
     image: docker.io/redis:6.2-alpine
     environment:
@@ -18,3 +31,8 @@ services:
       - "6379:6379"
     command:
       - "redis-server"
+    healthcheck:
+      test: ["CMD", "redis-cli", "ping"]
+      interval: 2s
+      timeout: 5s
+      retries: 30