feat(spanner-driver): integrate native spannerlib-node wrapper and implement type system

handwritten/spanner-driver/README.md

@@ -1,6 +1,6 @@
 # Google Spanner Node.js Driver (`@google-cloud/spanner-driver`)
 
-The `@google-cloud/spanner-driver` package provides a high-performance, `node-postgres` (`pg`) compatible client and connection pool interface for Google Spanner. It bridges Node.js applications directly to Spanner using a native Go CGO engine, delivering full PostgreSQL dialect support.
+The `@google-cloud/spanner-driver` package provides a high-performance, `node-postgres` (`pg`) compatible client and connection pool interface for Cloud Spanner, delivering full PostgreSQL dialect compatibility with low latency and seamless ORM integration.
 
 [![npm version](https://img.shields.io/npm/v/@google-cloud/spanner-driver.svg)](https://www.npmjs.com/package/@google-cloud/spanner-driver)
 [![License](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](LICENSE)
@@ -10,10 +10,14 @@ The `@google-cloud/spanner-driver` package provides a high-performance, `node-po
 ## Key Features
 
 - **`node-postgres` Compatibility**: Drop-in compatible `Client` and `Pool` interfaces matching standard PostgreSQL drivers.
-- **Connection Pooling**: Full-featured connection pool (`Pool`) with idle eviction, connection recycling (`maxUses`, `maxLifetimeSeconds`), and backpressure wait queues.
-- **Dual ESM & CommonJS**: Full support for both `import` (ESM) and `require()` (CommonJS) modules.
-- **PostgreSQL Dialect Utilities**: Escaping tools (`escapeIdentifier`, `escapeLiteral`) and SQLSTATE error code enrichment (`DatabaseError`).
-- **Flexible Invocation Modes**: Supports Promises (`async`/`await`), Node callbacks, and streaming row event emitters.
+- **High Performance**: Optimized, low-overhead communication directly with Cloud Spanner.
+- **Transaction Support**: Explicit transaction management (`BEGIN`, `COMMIT`, `ROLLBACK`) with transaction readiness status tracking (`client.txStatus`).
+- **Robust Connection Pooling**: Full-featured connection pool (`Pool`) with idle eviction, connection recycling (`maxUses`, `maxLifetimeSeconds`), backpressure wait queues, and async `onConnect` initialization hooks.
+- **Custom Type System**: `pg.types`-compatible `TypeOverrides` registry allowing global, per-client, or per-query custom parsers for PostgreSQL OID types.
+- **Rich Parameter Serialization**: Automatic encoding of JavaScript primitives, `Date` objects, `Buffer` bytes, JSON, and ORM objects implementing `.toPostgres()`.
+- **Flexible Invocation Modes**: Full support for Promises (`async`/`await`), Node callbacks (`(err, res) => ...`), and streaming row event emitters (`.on('row')`, `.on('fields')`).
+- **Dual ESM & CommonJS**: Native exports supporting both modern `import` (ESM) and legacy `require()` (CommonJS).
+- **PostgreSQL Utilities**: Escaping helpers (`escapeIdentifier`, `escapeLiteral`) and SQLSTATE error code enrichment (`DatabaseError`).
 
 ---
 
@@ -39,15 +43,16 @@ const client = new Client({
   database: 'my-spanner-database',
 });
 
-// Option B: Connection DSN String or postgresql:// URL
+// Option B: Connection DSN Resource String
 // const client = new Client('projects/my-gcp-project/instances/my-spanner-instance/databases/my-spanner-database');
 
 async function main() {
+  // connect() returns Promise<Client>
   await client.connect();
 
   // Executing queries with positional parameters ($1, $2, etc.)
   const result = await client.query(
-    'SELECT user_id, email FROM users WHERE status = $1',
+    'SELECT user_id, email, created_at FROM users WHERE status = $1',
     ['ACTIVE']
   );
 
@@ -61,6 +66,8 @@ async function main() {
 main().catch(console.error);
 ```
 
+---
+
 ### 2. Connection Pooling via `Pool`
 
 ```typescript
@@ -83,7 +90,6 @@ const pool = new Pool({
   },
 });
 
-// Pool Lifecycle Events (Fire-and-forget notifications)
 // Note: 'connect' event listeners do NOT wait for async functions; use onConnect option for async setup.
 pool.on('connect', client => console.log('New client connected to pool'));
 pool.on('acquire', client => console.log('Client checked out from pool'));
@@ -115,34 +121,121 @@ async function shutdown() {
 
 #### Monitoring Pool Metrics
 
-You can inspect real-time connection metrics on the `Pool` instance:
+You can inspect real-time connection metrics directly on the `Pool` instance:
 
 ```typescript
 console.log(`Total Connections: ${pool.totalCount}`);   // Total clients in pool (active + idle)
 console.log(`Idle Connections:  ${pool.idleCount}`);    // Clients currently available for checkout
 console.log(`Waiting Requests:  ${pool.waitingCount}`); // Queued queries waiting for an available client
 ```
 
-### 3. Streaming Rows & Callbacks
+---
+
+### 3. Streaming Rows & Events
 
 ```typescript
-import { Client } from '@google-cloud/spanner-driver';
+import { Client, Query } from '@google-cloud/spanner-driver';
 
 const client = new Client({
   project: 'my-gcp-project',
   instance: 'my-spanner-instance',
   database: 'my-spanner-database',
 });
 
-// Streaming row events
+await client.connect();
+
+// Stream rows as they arrive from Spanner gRPC stream
 client.query('SELECT * FROM large_table')
+  .on('fields', fields => console.log('Column metadata:', fields))
   .on('row', row => console.log('Received Row:', row))
-  .on('end', result => console.log('Query finished. Total rows:', result.rowCount))
-  .on('error', err => console.error('Error:', err));
+  .on('end', result => console.log('Query completed. Row count:', result.rowCount))
+  .on('error', err => console.error('Query error:', err));
 ```
 
 ---
 
+### 4. Custom Type Parsers (`types` & `TypeOverrides`)
+
+The driver provides a `node-postgres` compatible type system (`pg.types`) for customizing how PostgreSQL OID column types are deserialized:
+
+#### Global Type Parser Override
+
+```typescript
+import { types, BuiltinOids } from '@google-cloud/spanner-driver';
+
+// Example: Parse INT8 / BIGINT as native JavaScript BigInt globally
+types.setTypeParser(BuiltinOids.INT8, (val: string) => BigInt(val));
+
+// Example: Parse exact NUMERIC into a custom Decimal instance globally
+types.setTypeParser(BuiltinOids.NUMERIC, (val: string) => new Decimal(val));
+```
+
+#### Scoped Type Overrides (Per-Client or Per-Query)
+
+```typescript
+import { Client, TypeOverrides, BuiltinOids } from '@google-cloud/spanner-driver';
+
+// 1. Scoped to a specific Client instance
+const clientTypes = new TypeOverrides();
+clientTypes.setTypeParser(BuiltinOids.INT8, (val) => BigInt(val));
+
+const client = new Client({
+  project: 'my-project',
+  instance: 'my-instance',
+  database: 'my-db',
+  types: clientTypes, // Applies to all queries executed on this client
+});
+
+// 2. Scoped to a single Query execution
+const queryTypes = new TypeOverrides();
+queryTypes.setTypeParser(BuiltinOids.INT8, (val) => Number(val));
+
+const res = await client.query({
+  text: 'SELECT id, count FROM metrics WHERE id = $1',
+  values: [1],
+  types: queryTypes, // Only this query uses queryTypes
+});
+```
+
+#### Supported Data Types & Default Mappings
+
+| Spanner / PG Type | OID Code | Default JavaScript Output | Custom Parser Example |
+| :--- | :---: | :--- | :--- |
+| `BOOL` | `16` | `boolean` (`true` / `false`) | — |
+| `BYTEA` / `BYTES` | `17` | Node.js `Buffer` | Raw hex string |
+| `INT8` / `BIGINT` | `20` | `string` *(safe against $> 2^{53}-1$ overflow)* | `BigInt(val)` / `Number(val)` |
+| `INT2` / `SMALLINT` | `21` | `number` | — |
+| `INT4` / `INTEGER` | `23` | `number` | — |
+| `TEXT` / `VARCHAR` | `25` / `1043` | `string` | — |
+| `JSON` / `JSONB` | `114` / `3802` | `object` / `any` (`JSON.parse`) | Raw string |
+| `FLOAT4` / `REAL` | `700` | `number` | — |
+| `FLOAT8` / `FLOAT64` | `701` | `number` | — |
+| `DATE` | `1082` | `string` (`YYYY-MM-DD`) | `new Date(val)` |
+| `TIMESTAMP` / `TIMESTAMPTZ` | `1114` / `1184` | JavaScript `Date` (UTC) | ISO string |
+| `NUMERIC` | `1700` | `string` *(preserves exact decimal precision)* | `new Decimal(val)` |
+| `UUID` | `2950` | `string` | — |
+| `ARRAY<T>` | `1007`, `1016`, etc. | `T[]` *(nested arrays with element parser)* | Custom element parser |
+
+---
+
+## Spanner PostgreSQL Dialect Considerations
+
+When working with Cloud Spanner's PostgreSQL dialect, keep the following behavioral characteristics in mind:
+
+1. **`TIMESTAMPTZ` (1184) vs. `TIMESTAMP WITHOUT TIME ZONE` (1114)**:
+   - Cloud Spanner requires timezone-aware timestamps (`TIMESTAMPTZ`) for table column schemas. Creating a table column with `TIMESTAMP WITHOUT TIME ZONE` will be rejected by Spanner.
+   - The driver retains OID `1114` in `BuiltinOids` for backward compatibility with existing ORMs.
+2. **Timestamp Literals & Formatting**:
+   - Cloud Spanner requires ISO-8601 formatted timestamps (e.g. `'2026-08-11T12:00:00Z'`).
+   - The driver serializes JavaScript `Date` parameter values into ISO-8601 UTC strings. Invalid `Date` objects (`new Date('invalid')`) are safely serialized to `null`.
+3. **1D Schema Arrays vs. Multidimensional Expressions**:
+   - Cloud Spanner table schemas (`DDL`) permit only **1-dimensional arrays** (e.g. `VARCHAR[]`, `BIGINT[]`).
+   - SQL query projections and expressions can generate multidimensional arrays (e.g. `SELECT ARRAY[ARRAY[1, 2], ARRAY[3, 4]]`). The driver's array parser recursively decodes nested arrays into multidimensional JavaScript arrays (e.g. `[[1, 2], [3, 4]]`).
+4. **64-bit Integer Precision (`INT8` / `BIGINT`)**:
+   - By default, `INT8` columns are returned as strings to prevent precision loss beyond JavaScript's 53-bit `Number.MAX_SAFE_INTEGER` ($9,007,199,254,740,991$). Use `types.setTypeParser(BuiltinOids.INT8, BigInt)` or `Number` based on your application's requirements.
+
+---
+
 ## Configuration Reference
 
 ### `PoolConfig`
@@ -154,9 +247,10 @@ client.query('SELECT * FROM large_table')
 | `project` | `string` | `process.env.GOOGLE_CLOUD_PROJECT` | GCP Project ID. |
 | `instance` | `string` | — | Cloud Spanner Instance ID. |
 | `database` | `string` | — | Cloud Spanner Database ID. |
-| `connectionString` | `string` | — | Full Spanner resource path or `postgresql://` DSN URL. |
+| `connectionString` | `string` | — | Full Spanner resource path (`projects/p/instances/i/databases/d`). |
 | `host` | `string` | — | Optional custom endpoint or emulator host. |
 | `port` | `number` | — | Optional custom endpoint port. |
+| `types` | `ITypeOverrides` | `types` (global) | Custom type parser registry instance (`new TypeOverrides()`). |
 | `max` | `number` | `10` | Maximum number of active and idle connections in the pool. |
 | `min` | `number` | `0` | Minimum number of idle connections to retain without evicting. |
 | `idleTimeoutMillis` | `number` | `10000` (10s) | Time a connection can remain idle before being closed (set `0` to disable). |
@@ -174,11 +268,18 @@ client.query('SELECT * FROM large_table')
 | :--- | :--- | :--- |
 | `Client` | Class | Single database connection client (`connect()`, `query()`, `release()`, `end()`). |
 | `Pool` | Class | Connection pool manager (`connect()`, `query()`, `end()`, getters: `totalCount`, `idleCount`, `waitingCount`). |
+| `Query` | Class | Thenable query class supporting positional parameters, callbacks, rowMode, and event emitters. |
+| `types` | Object | Global default `TypeOverrides` registry matching `pg.types` (`getTypeParser()`, `setTypeParser()`, `builtins`). |
+| `TypeOverrides` | Class | Instantiable scoped type registry for client/query parser overrides. |
+| `BuiltinOids` | Enum | Standard PostgreSQL catalog Object Identifier (OID) constants. |
 | `DatabaseError` | Class | Enriched database error containing PostgreSQL SQLSTATE `.code` and `.severity`. |
-| `ClientConfig` | Interface | Client connection configuration options (`project`, `instance`, `database`, `connectionString`). |
+| `ClientConfig` | Interface | Client connection configuration options (`project`, `instance`, `database`, `connectionString`, `types`). |
 | `PoolConfig` | Interface | Pool management configuration options extending `ClientConfig`. |
 | `QueryResult` | Interface | Result set container (`rows`, `fields`, `rowCount`, `command`). |
-| `QueryConfig` | Interface | Query options object (`text`, `values`, `rowMode`). |
+| `QueryConfig` | Interface | Query options object (`text`, `values`, `rowMode`, `types`). |
+| `FieldDef` | Interface | Column metadata definition (`name`, `dataTypeID`). |
+| `ITypeOverrides` | Interface | Generic dialect-agnostic type codec interface. |
+| `TypeParser` | Type | Function type signature for parsing raw wire string into JavaScript value. |
 | `escapeIdentifier` | Function | Escapes PostgreSQL identifiers with double quotes (`"my_table"`). |
 | `escapeLiteral` | Function | Escapes PostgreSQL string literals with single quotes (`'val'`). |
 

handwritten/spanner-driver/package.json

@@ -41,6 +41,7 @@
     "test:esm": "c8 mocha build/esm/test/unit/**/*.js",
     "test:cjs": "c8 mocha build/cjs/test/unit/**/*.js",
     "test": "npm run test:esm && npm run test:cjs",
+    "system-test": "mocha build/esm/system-test/**/*.js --timeout 60000",
     "test:pg-suite": "node test/pg-suite/run_pg_suite.cjs"
   },
   "dependencies": {
@@ -58,5 +59,8 @@
   },
   "engines": {
     "node": ">=18"
+  },
+  "optionalDependencies": {
+    "spannerlib-node": "file:../../../go-sql-spanner/spannerlib/wrappers/spannerlib-node/spannerlib-node-0.1.0.tgz"
   }
 }

handwritten/spanner-driver/src/index.ts

@@ -15,21 +15,33 @@
 import {Client} from './lib/client.js';
 import {ClientConfig, PoolConfig} from './lib/config.js';
 import {DatabaseError} from './lib/errors.js';
+import {BuiltinOids, TypeOverrides, types} from './lib/pg/types.js';
 import {escapeIdentifier, escapeLiteral} from './lib/pg/utilities.js';
 import {Pool} from './lib/pool.js';
 import {Query} from './lib/query.js';
-import {FieldDef, QueryConfig, QueryResult} from './lib/types.js';
+import {
+  FieldDef,
+  ITypeOverrides,
+  QueryConfig,
+  QueryResult,
+  TypeParser,
+} from './lib/types.js';
 
 export {
+  BuiltinOids,
   Client,
   ClientConfig,
   DatabaseError,
   FieldDef,
+  ITypeOverrides,
   Pool,
   PoolConfig,
   Query,
   QueryConfig,
   QueryResult,
+  TypeOverrides,
+  TypeParser,
   escapeIdentifier,
   escapeLiteral,
+  types,
 };