fix(api): handle blank optional pipeline timestamps

crates/gitforge-api/Cargo.toml

@@ -43,6 +43,7 @@ prometheus = "0.14"
 hyper = "1.5"
 tempfile = "3"
 gitforge-review = { path = "../gitforge-review" }
+sqlx = { workspace = true }
 
 [lints]
 workspace = true

crates/gitforge-api/tests/ci_routes.rs

@@ -292,6 +292,49 @@ async fn pipeline_run_endpoints_scoped_and_expose_jobs_with_receipts() {
     assert_eq!(missing["error"], "not_found");
 }
 
+#[tokio::test]
+async fn pipeline_run_list_treats_blank_optional_finish_time_as_null() {
+    let f = seed().await;
+    sqlx::query("UPDATE pipeline_runs SET finished_at = '' WHERE id = ?")
+        .bind(f.run_id.to_string())
+        .execute(f.pool.pool())
+        .await
+        .unwrap();
+
+    let (status, runs) = request_json(
+        f.app,
+        "GET",
+        "/api/pipeline-runs",
+        Some(&f.owner_token),
+        None,
+    )
+    .await;
+    assert_eq!(status, StatusCode::OK, "response: {runs}");
+    assert_eq!(runs.as_array().unwrap().len(), 1);
+    assert_eq!(runs[0]["finished_at"], Value::Null);
+}
+
+#[tokio::test]
+async fn pipeline_run_list_still_rejects_malformed_nonblank_finish_time() {
+    let f = seed().await;
+    sqlx::query("UPDATE pipeline_runs SET finished_at = 'not-a-timestamp' WHERE id = ?")
+        .bind(f.run_id.to_string())
+        .execute(f.pool.pool())
+        .await
+        .unwrap();
+
+    let (status, body) = request_json(
+        f.app,
+        "GET",
+        "/api/pipeline-runs",
+        Some(&f.owner_token),
+        None,
+    )
+    .await;
+    assert_eq!(status, StatusCode::INTERNAL_SERVER_ERROR);
+    assert_eq!(body["error"], "database_error");
+}
+
 #[tokio::test]
 async fn submit_job_rejects_invalid_payloads() {
     let f = seed().await;

crates/gitforge-db/src/queries.rs

@@ -118,6 +118,7 @@ fn parse_optional_timestamp_column(
         .try_get(column)
         .map_err(|error| Error::database(format!("invalid {column} column: {error}")))?;
     value
+        .and_then(|value| (!value.trim().is_empty()).then_some(value))
         .map(|value| {
             DateTime::parse_from_rfc3339(&value)
                 .map(|date| date.with_timezone(&Utc))