feat: mysql integration ci

.github/workflows/ci.yml

@@ -76,3 +76,38 @@ jobs:
         env:
           RAIN_POSTGRES_DSN: postgres://rain:rain@127.0.0.1:5432/rain_test?sslmode=disable
         run: go test -race ./pkg/rain -run '^TestPostgresIntegration'
+
+  mysql-integration:
+    name: MySQL Integration Tests
+    runs-on: ubuntu-latest
+    needs: [precommit]
+    timeout-minutes: 10
+    services:
+      mysql:
+        image: mysql:8.4
+        env:
+          MYSQL_DATABASE: rain_test
+          MYSQL_USER: rain
+          MYSQL_PASSWORD: rain
+          MYSQL_ROOT_PASSWORD: root
+        ports:
+          - 3306:3306
+        options: >-
+          --health-cmd="mysqladmin ping -h 127.0.0.1 -urain -prain"
+          --health-interval=10s
+          --health-timeout=5s
+          --health-retries=10
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+
+      - name: Run MySQL integration tests
+        env:
+          RAIN_MYSQL_DSN: rain:rain@tcp(127.0.0.1:3306)/rain_test?parseTime=true
+        run: go test -race ./pkg/rain -run '^TestMySQLIntegration'

docs/adr/2026-03-29-mysql-integration-ci-design.md

@@ -0,0 +1,41 @@
+# ADR: MySQL integration coverage in CI
+
+## Status
+Accepted on 2026-03-29.
+
+## Context
+The repository already contains MySQL-backed integration coverage in `pkg/rain/mysql_integration_test.go`, and CI already runs separate SQLite and Postgres integration jobs.
+
+That leaves one gap in cross-dialect runtime verification: MySQL behavior is exercised locally when contributors provide a DSN, but it is not enforced as a distinct signal in GitHub Actions.
+
+The workflow already uses separate jobs per backend, so adding MySQL should preserve that structure rather than introducing a larger matrix refactor.
+
+## Decision
+Add a dedicated `mysql-integration` job to the existing GitHub Actions workflow.
+
+The new job:
+
+- uses `ubuntu-latest`
+- provisions a `mysql:8.4` service container
+- creates a fixed `rain_test` database with a `rain` user
+- passes `RAIN_MYSQL_DSN` to the test process
+- runs `go test -race ./pkg/rain -run '^TestMySQLIntegration'`
+
+Keep the existing SQLite and Postgres jobs unchanged.
+
+## Consequences
+### Positive
+- CI now exposes MySQL runtime compatibility as an independent signal.
+- Backend-specific failures remain isolated because each database keeps its own job.
+- The workflow change is incremental and consistent with the current CI layout.
+
+### Negative
+- CI runtime increases because another service-backed job must start and execute.
+- The workflow now contains some duplicated setup across database jobs.
+
+## Testing approach
+- Keep running the existing local validation flow:
+  - `make fmt`
+  - `make lint`
+  - `make test`
+- In GitHub Actions, run `go test -race ./pkg/rain -run '^TestMySQLIntegration'` in the dedicated MySQL job.

pkg/rain/mysql_integration_test.go

@@ -177,9 +177,9 @@ func defineMySQLTables(suffix string) (*mysqlUsersTable, *mysqlPostsTable) {
 	users := schema.Define("users_"+suffix, func(t *mysqlUsersTable) {
 		t.ID = t.BigSerial("id").PrimaryKey()
 		t.Email = t.VarChar("email", 255).NotNull()
-		t.Name = t.Text("name").NotNull().Default("guest")
+		t.Name = t.VarChar("name", 255).NotNull().Default("guest")
 		t.Active = t.Boolean("active").NotNull().Default(true)
-		t.Nickname = t.Text("nickname").Nullable().Default("buddy")
+		t.Nickname = t.VarChar("nickname", 255).Nullable().Default("buddy")
 		t.CreatedAt = t.TimestampTZ("created_at").NotNull().DefaultNow()
 	})