Centralize durable schema migration ownership

crates/remora-schema/tests/schema.rs

@@ -0,0 +1,65 @@
+use std::time::Duration;
+
+use remora_schema::{SCHEMA_GENERATION, generation, is_ready, migrate};
+use sqlx::{PgPool, postgres::PgPoolOptions};
+
+async fn test_pool() -> Option<PgPool> {
+    let Some(url) = std::env::var("DATABASE_URL")
+        .ok()
+        .filter(|value| !value.is_empty())
+    else {
+        if std::env::var("REMORA_SCHEMA_REQUIRE").is_ok() {
+            panic!("DATABASE_URL is required when REMORA_SCHEMA_REQUIRE is set");
+        }
+        return None;
+    };
+    Some(
+        PgPoolOptions::new()
+            .max_connections(12)
+            .acquire_timeout(Duration::from_secs(10))
+            .connect(&url)
+            .await
+            .expect("connect postgres"),
+    )
+}
+
+#[tokio::test]
+async fn migration_is_idempotent_and_marks_the_complete_generation() {
+    let Some(pool) = test_pool().await else {
+        return;
+    };
+    migrate(&pool).await.expect("first migration");
+    migrate(&pool).await.expect("second migration");
+    assert_eq!(
+        generation(&pool).await.expect("schema generation"),
+        Some(SCHEMA_GENERATION)
+    );
+    assert!(is_ready(&pool).await.expect("schema readiness"));
+
+    let table_count: i64 = sqlx::query_scalar(
+        "SELECT COUNT(*)::bigint
+         FROM information_schema.tables
+         WHERE table_schema = 'public'
+           AND table_name IN (
+             'mutation_records', 'principals', 'source_credentials', 'jobs',
+             'attempts', 'result_inventories', 'deletion_operations',
+             'live_event_history_state', 'worker_descriptors',
+             'remora_schema_state'
+           )",
+    )
+    .fetch_one(&pool)
+    .await
+    .expect("schema tables");
+    assert_eq!(table_count, 10);
+}
+
+#[tokio::test]
+async fn concurrent_owners_converge_before_readiness() {
+    let Some(pool) = test_pool().await else {
+        return;
+    };
+    let (first, second) = tokio::join!(migrate(&pool), migrate(&pool));
+    first.expect("first owner");
+    second.expect("second owner");
+    assert!(is_ready(&pool).await.expect("schema readiness"));
+}