Writing a driver

A driver is an object implementing DriverPlugin from @rizomadb/driver-api:

export const myDriver: DriverPlugin = {
  id: "mydb", displayName: "MyDB", family: "relational", capabilities, quoteIdent, placeholder: (i) => `$${i}`,
  selectTop: (table, n) => `SELECT * FROM ${table} LIMIT ${n}`, connectionSchema,
  async connect(cfg, ctx) { /* return a Connection */ },
};

Keep metadata (meta.ts: capabilities, schema, quoting) in a file that does not import the client library, so the extension host can show the connection form without loading it.

A Connection provides execute(req, signal) (an async iterator of columns, rows batches and one done event, honouring maxRows, batchSize and the AbortSignal), introspect(), ping(), close() and optionally begin().

Rules:

1. Errors are DriverError with a precise kind (syntax, authentication, permission, constraint, timeout, cancelled, connection). Syntax errors carry a 1-based position when the engine reports it.
2. 64-bit integers beyond 2^53 are bigint; decimals are strings; JSON is { json }; never lose precision silently, document it if the client library forces it.
3. If the server can terminate a connection mid-query, make sure pending reads reject (see the PostgreSQL and MySQL drivers for how hangs were fixed).
4. Declare readOnlyEnforcement honestly (server only if the engine rejects writes by itself).
5. Non-SQL engines set language, assess() (risk of a command) and, for editing, generateChange().

Run the shared kit in your tests: runConformance({ plugin, config, slowSql, paramSql, ... }) from @rizomadb/driver-api/conformance. Every bundled driver passes it against a real server. Third-party drivers are published as npm packages exporting a DriverPlugin; loading them in the extension is not implemented yet (drivers are bundled at build time).