test: prove 2.8 to 2.9.0 upgrade is lossless and fix what it caught

scripts/upgrade-sql.test.ts

@@ -0,0 +1,44 @@
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+import { LEGACY_TABLE_OWNERS } from "../packages/plugin-sdk/src/db";
+import { buildUpgradeSql } from "./lib/upgrade-sql.mjs";
+
+const SNAPSHOTS = path.resolve(
+  __dirname,
+  "../src/backend/tests/fixtures/upgrade",
+);
+
+const RENAME = {
+  postgres: /^ALTER TABLE "([a-z0-9_]+)" RENAME TO "(p_[a-z0-9_]+)";$/gm,
+  mysql: /^RENAME TABLE `([a-z0-9_]+)` TO `(p_[a-z0-9_]+)`;$/gm,
+};
+
+describe.each(["postgres", "mysql"] as const)(
+  "the 2.8 to 2.9.0 upgrade SQL on %s",
+  (dialect) => {
+    const sql = buildUpgradeSql(dialect);
+    const statements = sql.replace(/^--.*$/gm, "");
+
+    it("matches the reviewed snapshot", async () => {
+      await expect(sql).toMatchFileSnapshot(
+        path.join(SNAPSHOTS, `upgrade-${dialect}.sql`),
+      );
+    });
+
+    it("adopts every legacy table by renaming it, never by dropping it", () => {
+      const renamed = new Set(
+        [...sql.matchAll(RENAME[dialect])].map((match) => match[1]),
+      );
+      for (const table of Object.keys(LEGACY_TABLE_OWNERS)) {
+        expect(renamed, table).toContain(table);
+        expect(statements).not.toMatch(
+          new RegExp(`DROP TABLE[^;]*[\`"]${table}[\`"]`, "i"),
+        );
+      }
+    });
+
+    it("never drops a column", () => {
+      expect(statements).not.toMatch(/DROP COLUMN/i);
+    });
+  },
+);