fix: skip comment-only migration SQL

packages/db/src/migrate.ts

@@ -51,6 +51,50 @@ function section(content: string, which: "up" | "down"): string {
   return (next ? rest.slice(0, next.index) : rest).trim();
 }
 
+function hasExecutableSql(sql: string): boolean {
+  let quote = "";
+  let lineComment = false;
+  let blockComment = false;
+  for (let index = 0; index < sql.length; index++) {
+    const char = sql[index]!;
+    const next = sql[index + 1] ?? "";
+    if (lineComment) {
+      if (char === "\n" || char === "\r") lineComment = false;
+      continue;
+    }
+    if (blockComment) {
+      if (char === "*" && next === "/") {
+        blockComment = false;
+        index++;
+      }
+      continue;
+    }
+    if (quote) {
+      if (char === quote) {
+        if (next === quote) index++;
+        else quote = "";
+      }
+      continue;
+    }
+    if (char === "-" && next === "-") {
+      lineComment = true;
+      index++;
+      continue;
+    }
+    if (char === "/" && next === "*") {
+      blockComment = true;
+      index++;
+      continue;
+    }
+    if (char === "'" || char === '"' || char === "`") {
+      quote = char;
+      return true;
+    }
+    if (!/\s|;/.test(char)) return true;
+  }
+  return false;
+}
+
 /** Load and parse all migration files in a directory, sorted by filename. */
 export function loadMigrations(dir: string): Migration[] {
   if (!existsSync(dir)) return [];
@@ -136,7 +180,7 @@ export async function applyMigrations(
     for (const migration of pending.filter(({ name }) => !current.has(name))) {
       throwIfAborted(options.signal);
       await db.tx(async (tx) => {
-        if (migration.up) await tx.exec(migration.up);
+        if (hasExecutableSql(migration.up)) await tx.exec(migration.up);
         await tx.exec(`INSERT INTO ${MIGRATIONS_TABLE} (name) VALUES (?)`, [migration.name]);
       });
       done.push(migration.name);
@@ -175,7 +219,7 @@ export async function rollback(
   try {
     throwIfAborted(options.signal);
     await db.tx(async (tx) => {
-      if (migration?.down) await tx.exec(migration.down);
+      if (migration && hasExecutableSql(migration.down)) await tx.exec(migration.down);
       await tx.exec(`DELETE FROM ${MIGRATIONS_TABLE} WHERE name = ?`, [last]);
     });
     return last;