fix: app history lists in deployed order, so the picker numbers it right

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/.sqlx/query-c8b369881add5574c1762431e2fb58eb04892babb4684be314f369227424e640.json

@@ -1,6 +1,6 @@
 {
   "db_name": "PostgreSQL",
-  "query": "SELECT a.id as app_id, av.id as version_id, dm.deployment_msg as deployment_msg,\n                av.created_by as created_by, av.created_at as created_at\n        FROM app a LEFT JOIN app_version av ON a.id = av.app_id LEFT JOIN deployment_metadata dm ON av.id = dm.app_version\n        WHERE a.workspace_id = $1 AND a.path = $2\n        ORDER BY av.created_at DESC",
+  "query": "SELECT a.id as app_id, av.id as version_id, dm.deployment_msg as deployment_msg,\n                av.created_by as created_by, av.created_at as created_at\n        FROM app a LEFT JOIN app_version av ON a.id = av.app_id LEFT JOIN deployment_metadata dm ON av.id = dm.app_version\n        WHERE a.workspace_id = $1 AND a.path = $2\n        ORDER BY array_position(a.versions, av.id) DESC NULLS LAST, av.id DESC",
   "describe": {
     "columns": [
       {
@@ -43,5 +43,5 @@
       false
     ]
   },
-  "hash": "1b1607e9933f8f843d05e6a1601712d042bb3fd6454802bc686c4fd1dd47a4e6"
+  "hash": "c8b369881add5574c1762431e2fb58eb04892babb4684be314f369227424e640"
 }

backend/tests/app_version_order.rs

@@ -0,0 +1,102 @@
+//! The deployed order of an app's versions is the order they were appended to
+//! `app.versions`, not the order of their `created_at`.
+//!
+//! `app_version.created_at` defaults to `now()`, which in Postgres is the
+//! transaction's start time, while the append happens under the app row's lock.
+//! Two deploys that overlap therefore land in one order and carry timestamps in
+//! the other. The head the editor guards against, and the sequence the diff
+//! picker numbers, both have to follow the array.
+//!
+//! Users from the `base` fixture: test-user (admin, token SECRET_TOKEN).
+
+use serde_json::json;
+use sqlx::{Pool, Postgres};
+use windmill_test_utils::*;
+
+const TOKEN: &str = "SECRET_TOKEN";
+
+#[sqlx::test(fixtures("base"))]
+async fn test_app_head_follows_the_append_order_not_the_timestamps(
+    db: Pool<Postgres>,
+) -> anyhow::Result<()> {
+    initialize_tracing().await;
+    let server = ApiServer::start(db.clone()).await?;
+    let ws = format!(
+        "http://localhost:{}/api/w/test-workspace",
+        server.addr.port()
+    );
+    let client = reqwest::Client::new();
+
+    let res = client
+        .post(format!("{ws}/apps/create"))
+        .header("Authorization", format!("Bearer {TOKEN}"))
+        .json(&json!({
+            "path": "u/test-user/order_app",
+            "summary": "ordered",
+            "value": {},
+            "policy": { "execution_mode": "publisher", "triggerables": {} }
+        }))
+        .send()
+        .await?;
+    assert!(res.status().is_success(), "{}", res.text().await?);
+
+    let first: i64 = sqlx::query_scalar!(
+        "SELECT versions[array_upper(versions, 1)] FROM app
+         WHERE workspace_id = 'test-workspace' AND path = 'u/test-user/order_app'"
+    )
+    .fetch_one(&db)
+    .await?
+    .expect("the created app has a version");
+
+    // The overlapping deploy: appended after `first`, so it is the version that
+    // landed, but stamped before it, so a timestamp sort puts it underneath.
+    let second: i64 = sqlx::query_scalar!(
+        "INSERT INTO app_version (app_id, value, created_by, created_at, raw_app)
+         SELECT app_id, value, 'racer', created_at - interval '1 hour', raw_app
+         FROM app_version WHERE id = $1
+         RETURNING id",
+        first
+    )
+    .fetch_one(&db)
+    .await?;
+    sqlx::query!(
+        "UPDATE app SET versions = array_append(versions, $1::bigint)
+         WHERE workspace_id = 'test-workspace' AND path = 'u/test-user/order_app'",
+        second
+    )
+    .execute(&db)
+    .await?;
+
+    let head: serde_json::Value = client
+        .get(format!(
+            "{ws}/apps/get_latest_version/u/test-user/order_app"
+        ))
+        .header("Authorization", format!("Bearer {TOKEN}"))
+        .send()
+        .await?
+        .json()
+        .await?;
+    assert_eq!(
+        head["version"], second,
+        "the head is the version appended last, not the newest timestamp: {head}"
+    );
+
+    let history: Vec<serde_json::Value> = client
+        .get(format!("{ws}/apps/history/p/u/test-user/order_app"))
+        .header("Authorization", format!("Bearer {TOKEN}"))
+        .send()
+        .await?
+        .json()
+        .await?;
+    let listed: Vec<i64> = history
+        .iter()
+        .map(|v| v["version"].as_i64().unwrap())
+        .collect();
+    assert_eq!(
+        listed,
+        vec![second, first],
+        "the picker numbers the history by deployed order, so it leads with the head"
+    );
+
+    Ok(())
+}

backend/windmill-api/src/apps.rs

@@ -1241,12 +1241,18 @@ async fn get_app_history(
     let path = path.to_path();
     check_scopes(&authed, || format!("apps:read:{}", &path))?;
     let mut tx = user_db.begin(&authed).await?;
+    // Newest first in the order the versions were deployed, which the picker numbers
+    // (`v1`, `v2`, …) and reads the head off. That is the position in `app.versions`,
+    // not `created_at`: the latter is the deploying transaction's start time, so two
+    // that overlap can carry it in the opposite order from the one they landed in. A
+    // version absent from the array (restored from trash, copied by a fork) never sat
+    // in that sequence, so it trails the ones that did.
     let query_result = sqlx::query!(
         "SELECT a.id as app_id, av.id as version_id, dm.deployment_msg as deployment_msg,
                 av.created_by as created_by, av.created_at as created_at
         FROM app a LEFT JOIN app_version av ON a.id = av.app_id LEFT JOIN deployment_metadata dm ON av.id = dm.app_version
         WHERE a.workspace_id = $1 AND a.path = $2
-        ORDER BY av.created_at DESC",
+        ORDER BY array_position(a.versions, av.id) DESC NULLS LAST, av.id DESC",
         w_id,
         path,
     ).fetch_all(&mut *tx).await?;