fix(assistant): mysql message storage, migration metadata and per-page bundle cost (#6530)

packages/db/migrations/mysql/0044_add_assistant.sql

@@ -26,7 +26,7 @@ CREATE TABLE `assistant_message` (
 	`thread_id` varchar(64) NOT NULL,
 	`parent_id` varchar(128),
 	`format` varchar(64) DEFAULT 'ai-sdk/v6' NOT NULL,
-	`content` text DEFAULT ('{"json": {}}') NOT NULL,
+	`content` mediumtext DEFAULT ('{"json": {}}') NOT NULL,
 	`created_at` timestamp DEFAULT (now()) NOT NULL,
 	CONSTRAINT `assistant_message_id` PRIMARY KEY(`id`)
 );

packages/db/schema/mysql.ts

@@ -9,6 +9,7 @@ import {
   foreignKey,
   index,
   int,
+  mediumtext,
   mysqlTable,
   primaryKey,
   smallint,
@@ -487,6 +488,7 @@ export const assistantConfigurations = mysqlTable("assistant_configuration", {
   webSearchEnabled: boolean().notNull().default(false),
   provider: varchar({ length: 32 })
     .$type<
+      | "homarr"
       | "openrouter"
       | "openai"
       | "anthropic"
@@ -536,7 +538,9 @@ export const assistantMessages = mysqlTable(
       .references(() => assistantThreads.id, { onDelete: "cascade" }),
     parentId: varchar({ length: 128 }),
     format: varchar({ length: 64 }).notNull().default("ai-sdk/v6"),
-    content: text().default(emptySuperJSON).notNull(),
+    // `text` only holds 64KB on MySQL, which a single base64 image attachment already exceeds.
+    // `mediumtext` holds 16MB, comfortably above the 2MB request cap enforced by the chat route.
+    content: mediumtext().notNull(),
     createdAt: timestamp().notNull().defaultNow(),
   },
   (message) => ({

packages/db/test/migration-journal.spec.ts

@@ -0,0 +1,98 @@
+import fs from "fs";
+import path from "path";
+import { describe, expect, test } from "vitest";
+
+/**
+ * Guards the migration folders against the failure modes that have actually shipped:
+ *
+ * - v1.70.0 shipped `0042_add_widget_secret.sql` for MySQL without a `_journal.json` entry, so the
+ *   migrator never ran it and MySQL instances upgraded from that release had no `widget_secret`
+ *   table.
+ * - The follow-up fix hand-wrote `0042_snapshot.json` with a `checkConstraints` key instead of
+ *   `checkConstraint`, which made `drizzle-kit generate` reject the folder and silently exit 0 for
+ *   every later MySQL migration.
+ */
+const dialects = ["mysql", "postgresql", "sqlite"] as const;
+
+const migrationsRoot = path.join(__dirname, "..", "migrations");
+
+interface Journal {
+  entries: { idx: number; tag: string }[];
+}
+
+const readDialect = (dialect: (typeof dialects)[number]) => {
+  const folder = path.join(migrationsRoot, dialect);
+  const journal = JSON.parse(fs.readFileSync(path.join(folder, "meta", "_journal.json"), "utf8")) as Journal;
+  const sqlFiles = fs
+    .readdirSync(folder)
+    .filter((file) => file.endsWith(".sql"))
+    .map((file) => file.replace(/\.sql$/u, ""));
+  const snapshots = fs
+    .readdirSync(path.join(folder, "meta"))
+    .filter((file) => /^\d+_snapshot\.json$/u.test(file))
+    .map((file) => file.split("_")[0]);
+
+  return { folder, journal, sqlFiles, snapshots };
+};
+
+describe.each(dialects)("%s migrations", (dialect) => {
+  test("every journal entry has a matching .sql file", () => {
+    const { journal, sqlFiles } = readDialect(dialect);
+    const missing = journal.entries.filter((entry) => !sqlFiles.includes(entry.tag)).map((entry) => entry.tag);
+
+    expect(missing).toEqual([]);
+  });
+
+  test("every .sql file is registered in the journal", () => {
+    const { journal, sqlFiles } = readDialect(dialect);
+    const tags = new Set(journal.entries.map((entry) => entry.tag));
+    const orphans = sqlFiles.filter((file) => !tags.has(file));
+
+    expect(orphans).toEqual([]);
+  });
+
+  test("every journal entry has a matching snapshot", () => {
+    const { journal, snapshots } = readDialect(dialect);
+    const missing = journal.entries
+      .filter((entry) => !snapshots.includes(String(entry.idx).padStart(4, "0")))
+      .map((entry) => entry.tag);
+
+    expect(missing).toEqual([]);
+  });
+
+  test("journal indexes are unique and gap-free", () => {
+    const { journal } = readDialect(dialect);
+    const indexes = journal.entries.map((entry) => entry.idx);
+
+    expect(indexes).toEqual(indexes.map((_, position) => position));
+  });
+
+  // The check-constraint key is spelled differently per snapshot format version (MySQL's v5 uses
+  // `checkConstraint`, the newer SQLite/Postgres formats use `checkConstraints`), so rather than
+  // hard-coding a spelling this asserts every snapshot in a dialect agrees with the others. A
+  // hand-written snapshot that gets it wrong stands out as the odd one and fails drizzle-kit.
+  test("all snapshots agree on the check-constraint key spelling", () => {
+    const { folder, snapshots } = readDialect(dialect);
+
+    const spellingsPerSnapshot = snapshots.map((snapshot) => {
+      const file = path.join(folder, "meta", `${snapshot}_snapshot.json`);
+      const parsed = JSON.parse(fs.readFileSync(file, "utf8")) as { tables?: Record<string, object> };
+      const spellings = new Set<string>();
+
+      for (const table of Object.values(parsed.tables ?? {})) {
+        if ("checkConstraint" in table) spellings.add("checkConstraint");
+        if ("checkConstraints" in table) spellings.add("checkConstraints");
+      }
+
+      return { snapshot, spellings: [...spellings].toSorted().join("+") };
+    });
+
+    const used = [...new Set(spellingsPerSnapshot.map((entry) => entry.spellings))].filter(
+      (spelling) => spelling.length > 0,
+    );
+
+    expect(used, `snapshots disagree: ${JSON.stringify(spellingsPerSnapshot.filter((e) => e.spellings))}`).toHaveLength(
+      1,
+    );
+  });
+});

packages/db/test/mysql-migration.spec.ts

@@ -1,6 +1,7 @@
 import path from "path";
 import { readFileSync } from "node:fs";
 import { MySqlContainer } from "@testcontainers/mysql";
+import { eq } from "drizzle-orm";
 import { drizzle } from "drizzle-orm/mysql2";
 import { migrate } from "drizzle-orm/mysql2/migrator";
 import mysql from "mysql2";
@@ -56,6 +57,22 @@ describe("Mysql Migration", () => {
       .query<mysql.RowDataPacket[]>("SHOW TABLES LIKE 'custom_widget%'");
     expect(customWidgetTables).toHaveLength(4);
 
+    // A single base64 image attachment already exceeds the 64KB that `text` holds on MySQL, so
+    // `assistant_message.content` has to be `mediumtext`. Everything below 64KB passes either way.
+    const largeContent = "x".repeat(200_000);
+    await database.insert(mysqlSchema.users).values({ id: "size-check-user", name: "size-check" });
+    await database.insert(mysqlSchema.assistantThreads).values({ id: "size-check-thread", userId: "size-check-user" });
+    await database.insert(mysqlSchema.assistantMessages).values({
+      id: "size-check-message",
+      threadId: "size-check-thread",
+      parentId: null,
+      content: largeContent,
+    });
+    const [storedMessage] = await database.query.assistantMessages.findMany({
+      where: eq(mysqlSchema.assistantMessages.id, "size-check-message"),
+    });
+    expect(storedMessage?.content).toHaveLength(largeContent.length);
+
     connection.end();
     await mysqlContainer.stop();
   }, 120_000);