fix: preview actual DROP INDEX sql in drop confirmation

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/windmill-worker/src/pg_executor.rs

@@ -2005,6 +2005,29 @@ impl FromSql<'_> for StringCollector {
 mod tests {
     use super::*;
 
+    #[test]
+    fn test_statement_requires_no_transaction() {
+        // CONCURRENTLY index DDL must bypass the implicit transaction.
+        assert!(statement_requires_no_transaction(
+            "CREATE INDEX CONCURRENTLY idx ON t (a)"
+        ));
+        assert!(statement_requires_no_transaction(
+            "create unique index concurrently idx on t (a)"
+        ));
+        assert!(statement_requires_no_transaction(
+            "DROP INDEX CONCURRENTLY IF EXISTS idx"
+        ));
+        assert!(statement_requires_no_transaction(
+            "  REINDEX INDEX CONCURRENTLY idx"
+        ));
+        // Plain DDL and unrelated statements stay on the normal path.
+        assert!(!statement_requires_no_transaction(
+            "CREATE INDEX idx ON t (a)"
+        ));
+        assert!(!statement_requires_no_transaction("DROP INDEX idx"));
+        assert!(!statement_requires_no_transaction("SELECT 1"));
+    }
+
     #[test]
     fn test_parse_naive_date() {
         // chrono's NaiveDate::to_string() format

frontend/src/lib/components/DBIndexManager.svelte

@@ -109,17 +109,29 @@
 		}
 	}
 
-	function openDropConfirm(idx: DbIndex) {
-		confirm = {
-			open: true,
-			title: `Drop index "${idx.name}"?`,
-			confirmationText: 'Drop index',
-			code: idx.definition,
-			onConfirm: async () => {
-				await dbIndexOps.dropIndex({ name: idx.name, schema, concurrent: true })
-				sendUserToast('Index dropped')
-				indexes.refetch()
+	async function openDropConfirm(idx: DbIndex) {
+		busy = true
+		try {
+			const sql = await dbIndexOps.previewDropIndexSql({
+				name: idx.name,
+				schema,
+				concurrent: true
+			})
+			confirm = {
+				open: true,
+				title: `Drop index "${idx.name}"?`,
+				confirmationText: 'Drop index',
+				code: sql,
+				onConfirm: async () => {
+					await dbIndexOps.dropIndex({ name: idx.name, schema, concurrent: true })
+					sendUserToast('Index dropped')
+					indexes.refetch()
+				}
 			}
+		} catch (e) {
+			toastErr(e)
+		} finally {
+			busy = false
 		}
 	}
 

frontend/src/lib/components/dbOps.ts

@@ -301,6 +301,11 @@ export type IDbIndexOps = {
 		values: CreateIndexInput
 	}) => Promise<string>
 	dropIndex: (params: { name: string; schema?: string; concurrent?: boolean }) => Promise<void>
+	previewDropIndexSql: (params: {
+		name: string
+		schema?: string
+		concurrent?: boolean
+	}) => Promise<string>
 }
 
 export function dbIndexOpsWithPreviewScripts({
@@ -366,6 +371,10 @@ export function dbIndexOpsWithPreviewScripts({
 				workspace,
 				requestBody: { args: { ...dbArg }, language, content }
 			})
+		},
+		previewDropIndexSql: async ({ name, schema, concurrent }) => {
+			const content = makeMarker('DROP_INDEX', { name, schema, concurrent: concurrent ?? false })
+			return expandMarker(workspace, language, content)
 		}
 	}
 }