TypeScript knows your SQL is broken before your tests even run

const result = await db.query('SELECT * WHERE id = ?', [42]);

type Head<S extends string> =
  S extends `${infer H} ${infer _}` ? H : S;

type Tail<S extends string> =
  S extends `${infer _} ${infer T}` ? T : "";

type StateAfterSELECT<S extends string, Full extends string> =
  S extends ""
    ? never                                       // no FROM → invalid
    : Uppercase<Head<S>> extends "FROM"
      ? StateAfterFROM<Tail<S>, Full>             // found FROM → next state
      : StateAfterSELECT<Tail<S>, Full>;          // consume token, recurse

import type { SQLParams } from '@playwright-labs/sql-core';

type A = SQLParams<'SELECT * FROM users WHERE id = ?'>;
//   ^-- [unknown]  ✅

type B = SQLParams<'SELECT * WHERE id = ?'>;
//   ^-- never  ❌ missing FROM

type C = SQLParams<'UPDATE users WHERE id = ?'>;
//   ^-- never  ❌ missing SET

type D = SQLParams<'SELECT * FROM t WHERE id = $3'>;
//   ^-- never  ❌ $1 and $2 are missing (sequential validation!)

import { sql } from '@playwright-labs/sql-core';

const q1 = sql("SELECT * FROM users WHERE id = ?");
// typeof q1 → SqlStatement<[unknown]>

const q2 = sql("SELECT * WHERE id = ?");
// typeof q2 → never  ❌ compile error right here

await client.query(q1, [42]);    // ✅
await client.query(q1);          // ❌ params required
await client.query(q1, [1, 2]);  // ❌ too many params

// without fixture-sql — every. single. test. file.
let db: Client;
beforeEach(async () => { db = await pgConnect(); });
afterEach(async () => { await db.end(); });

import { test, expect } from '@playwright-labs/fixture-sql';
import { sqliteAdapter } from '@playwright-labs/fixture-sql/sqlite';

test.use({ sqlAdapter: sqliteAdapter(':memory:') });

test('insert and read', async ({ sql: db }) => {
  await db.execute(sql`CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)`);
  await db.execute(sql`INSERT INTO users VALUES (1, 'Alice')`);

  const { rows } = await db.query<{ name: string }>(
    sql("SELECT name FROM users WHERE id = ?"),
    [1],
  );
  expect(rows[0]!.name).toBe('Alice');
});

{
  "compilerOptions": {
    "plugins": [{
      "name": "@playwright-labs/ts-plugin-sql",
      "schemaFile": "./src/db-types.ts"
    }]
  }
}

pnpm playwright-labs-fixture-sql pull --adapter sqlite --url ./dev.db --out ./src/db-types.ts

sql`SELECT ...` // rest

pnpm add -D @playwright-labs/fixture-sql @playwright-labs/ts-plugin-sql
pnpm add -D better-sqlite3