--- title: "Integration Test Harness" description: "The integration test harness coordinates multi-dialect validation suites across local environments and continuous integration pipelines, verifying database driver behavior, schema migrations, and q..." last_updated: "2026-10-12T08:14:00.74232+00:00" canonical_url: "https://www.doc0.dev/docs/e1b68fed-3c4e-4c95-b2ba-ebf050f78025/technical/testing-and-tooling/integration-test-harness" ---
Relevant source files The following files were used as context for generating this wiki page: - [integration-tests/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/vitest.config.ts) - [integration-tests/package.json](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/package.json) - [drizzle-kit/src/cli/connections.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-kit/src/cli/connections.ts) - [drizzle-orm/type-tests/singlestore/tables.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/tables.ts) - [drizzle-seed/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-seed/vitest.config.ts) - [drizzle-kit/src/api.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-kit/src/api.ts) - [drizzle-kit/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-kit/vitest.config.ts) - [integration-tests/vitest-ci.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/vitest-ci.config.ts) - [integration-tests/sst.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/sst.config.ts) - [drizzle-arktype/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-arktype/vitest.config.ts) - [drizzle-orm/type-tests/sqlite/db.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/sqlite/db.ts) - [drizzle-orm/src/singlestore/session.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/src/singlestore/session.ts) - [drizzle-valibot/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-valibot/vitest.config.ts) - [drizzle-orm/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/vitest.config.ts) - [eslint-plugin-drizzle/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/eslint-plugin-drizzle/vitest.config.ts) - [drizzle-typebox/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-typebox/vitest.config.ts) - [drizzle-kit/src/serializer/studio.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-kit/src/serializer/studio.ts) - [drizzle-zod/vitest.config.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-zod/vitest.config.ts) - [drizzle-kit/src/sqlgenerator.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-kit/src/sqlgenerator.ts) - [drizzle-orm/src/pglite/driver.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/src/pglite/driver.ts) - [drizzle-orm/src/singlestore/driver.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/src/singlestore/driver.ts) - [drizzle-seed/type-tests/pg.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-seed/type-tests/pg.ts) - [drizzle-orm/type-tests/singlestore/db.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/db.ts) - [drizzle-seed/type-tests/sqlite.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-seed/type-tests/sqlite.ts) - [integration-tests/drizzle2/sqlite/meta/_journal.json](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/sqlite/meta/_journal.json) - [integration-tests/drizzle2/pg/meta/_journal.json](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/pg/meta/_journal.json) - [integration-tests/sst-env.d.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/sst-env.d.ts) - [integration-tests/drizzle2/singlestore/meta/_journal.json](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/singlestore/meta/_journal.json) - [integration-tests/drizzle2/pg-proxy/first/meta/_journal.json](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/pg-proxy/first/meta/_journal.json) - [drizzle-orm/type-tests/singlestore/select.ts](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/select.ts)
## Overview The integration test harness coordinates multi-dialect validation suites across local environments and continuous integration pipelines, verifying database driver behavior, schema migrations, and query execution semantics. By combining Vitest runner configurations, AWS SST infrastructure fixtures, and multi-dialect snapshot journals, the suite validates database interactions across SQLite, PostgreSQL, MySQL, SingleStore, and Gel. Sources: [integration-tests/vitest.config.ts:6-24](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/vitest.config.ts#L6-L24), [integration-tests/package.json:74-74](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/package.json#L74-L74), [integration-tests/drizzle2/sqlite/meta/_journal.json:1-13](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/sqlite/meta/_journal.json#L1-L13) ## Vitest runner configuration across environments ### Local and CI configuration structures The integration test suite utilizes distinct Vitest runner configurations for local execution and continuous integration environments. Local runs are governed by `integration-tests/vitest.config.ts`, which loads environment variables via `dotenv/config` and resolves TypeScript path mappings through `vite-tsconfig-paths`. The local configuration explicitly defines inclusion globs covering relational tests, dialect-specific test suites, driver initializations, and vector or spatial extensions. ```typescript test: { include: [ 'tests/seeder/**/*.test.ts', 'tests/extensions/postgis/**/*', 'tests/relational/**/*.test.ts', 'tests/pg/**/*.test.ts', 'tests/mysql/**/*.test.ts', 'tests/singlestore/**/*.test.ts', 'tests/sqlite/**/*.test.ts', 'tests/replicas/**/*', 'tests/imports/**/*', 'tests/extensions/vectors/**/*', 'tests/version.test.ts', 'tests/pg/node-postgres.test.ts', 'tests/utils/is-config.test.ts', 'js-tests/driver-init/commonjs/*.test.cjs', 'js-tests/driver-init/module/*.test.mjs', 'tests/gel/**/*.test.ts', ], ``` Sources: [integration-tests/vitest.config.ts:6-24](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/vitest.config.ts#L6-L24) > [!NOTE] > When `SKIP_EXTERNAL_DB_TESTS` is active in the environment, local execution automatically filters out tests requiring remote or external database services such as PlanetScale, Neon, TiDB, LibSQL, and Vercel. Continuous integration runs are directed by `integration-tests/vitest-ci.config.ts`, which omits the verbose `include` and `exclude` pattern arrays to streamline execution while retaining core test timeouts, single-thread pool options, and type checking constraints. ```typescript export default defineConfig({ test: { typecheck: { tsconfig: 'tsconfig.json', }, testTimeout: 100000, hookTimeout: 200000, isolate: true, poolOptions: { threads: { singleThread: true, }, }, maxWorkers: 1, fileParallelism: false, }, ``` Sources: [integration-tests/vitest-ci.config.ts:5-20](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/vitest-ci.config.ts#L5-L20) ### Execution parameter matrix Both local and CI runner configurations enforce strict concurrency controls and execution boundaries to prevent race conditions against shared or local database instances. The parameter configuration defines explicit timeouts, worker limits, and isolation rules. | Parameter | Configuration Key | Value | Purpose | | :--- | :--- | :--- | :--- | | Test Timeout | `testTimeout` | `100000` | Maximum execution time in milliseconds allotted to an individual test case. | | Hook Timeout | `hookTimeout` | `200000` | Maximum execution time in milliseconds allotted to setup and teardown hooks. | | Test Isolation | `isolate` | `true` | Ensures test files run in isolated environments to avoid state leakage. | | Single Thread | `poolOptions.threads.singleThread` | `true` | Forces test execution onto a single thread within the pool. | | Max Workers | `maxWorkers` | `1` | Restricts parallel worker processes to prevent database connection contention. | | File Parallelism | `fileParallelism` | `false` | Disables concurrent test file execution across workers. | Sources: [integration-tests/vitest.config.ts:70-83](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/vitest.config.ts#L70-L83), [integration-tests/vitest-ci.config.ts:7-19](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/vitest-ci.config.ts#L7-L19) ## Infrastructure provisioning with SST fixtures ### Cloud stack orchestration and AWS Postgres configuration The integration test suite utilizes SST (Serverless Stack) to orchestrate cloud infrastructure stacks for serverless database validation. The configuration file `integration-tests/sst.config.ts` includes a triple-slash reference to `./.sst/platform/config.d.ts` for type safety and is exported via the `$config` function block. ```typescript // eslint-disable-next-line @typescript-eslint/triple-slash-reference /// export default $config({ app(_input) { return { name: 'awsdataapi', removal: 'remove', home: 'aws', }; }, async run() { new sst.aws.Postgres('Postgres', { scaling: { min: '0.5 ACU', max: '1 ACU', }, }); }, ``` Sources: [integration-tests/sst.config.ts:1-19](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/sst.config.ts#L1-L19) | Configuration Property | Target Value / Setting | Context | | :--- | :--- | :--- | | App Name | `awsdataapi` | Defined within the `app` hook callback. | | Removal Policy | `remove` | Specifies stack teardown behavior upon destruction. | | Home Provider | `aws` | Designates AWS as the infrastructure provider. | | Postgres Resource ID | `Postgres` | Instantiated via `new sst.aws.Postgres('Postgres', ...)`. | | Minimum ACU | `0.5 ACU` | Serverless scaling lower bound for the Postgres instance. | | Maximum ACU | `1 ACU` | Serverless scaling upper bound for the Postgres instance. | Sources: [integration-tests/sst.config.ts:4-19](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/sst.config.ts#L4-L19) > [!NOTE] > The serverless PostgreSQL resource scales dynamically between 0.5 and 1 Aurora Capacity Units (ACU) to accommodate AWS Data API integration tests without maintaining idle compute overhead. ### Generated environment bindings Environment binding synchronization for the SST stack is managed through generated type definition files. The file `integration-tests/sst-env.d.ts` establishes type references for runtime resource bindings generated during stack deployment. ```typescript // eslint-disable-next-line @typescript-eslint/triple-slash-reference /// ``` Sources: [integration-tests/sst-env.d.ts:1-2](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/sst-env.d.ts#L1-L2) > [!WARNING] > Manual modifications to `sst-env.d.ts` will be overwritten when SST generates new environment type definitions from the active stack state. ## Cross dialect migration journal fixtures ### Migration journal schema and dialect variants Integration tests validate schema change tracking and snapshot generation by utilizing multi-dialect migration journal fixtures. Each migration journal is defined inside a `meta/_journal.json` configuration file, specifying the schema metadata version, target SQL dialect, and sequential entries detailing individual migration steps. The journal format records metadata such as transaction timestamps, unique tags, and breakpoint configurations. ```json { "version": "5", "dialect": "sqlite", "entries": [ { "idx": 0, "version": "5", "when": 1680202256473, "tag": "0000_fancy_bug", "breakpoints": true } ] ``` Sources: [integration-tests/drizzle2/sqlite/meta/_journal.json:1-12](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/sqlite/meta/_journal.json#L1-L12) The migration journals capture differences across database engines. For example, PostgreSQL journal configurations accommodate single and multi-step migration histories, whereas SQLite and SingleStore maintain target-specific format versions. ```json { "version": "5", "dialect": "pg", "entries": [ { "idx": 0, "version": "5", "when": 1680271923328, "tag": "0000_puzzling_flatman", "breakpoints": true }, { "idx": 1, "version": "5", "when": 1680271923329, "tag": "0001_test", "breakpoints": true } ] ``` Sources: [integration-tests/drizzle2/pg/meta/_journal.json:1-19](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/pg/meta/_journal.json#L1-L19) | Dialect | Journal File Path | Version | Entry Count | Dialect Identifier | | :--- | :--- | :--- | :--- | :--- | | SQLite | `integration-tests/drizzle2/sqlite/meta/_journal.json` | `5` | `1` | `sqlite` | | PostgreSQL | `integration-tests/drizzle2/pg/meta/_journal.json` | `5` | `2` | `pg` | | SingleStore | `integration-tests/drizzle2/singlestore/meta/_journal.json` | `1` | `1` | `singlestore` | | PostgreSQL Proxy | `integration-tests/drizzle2/pg-proxy/first/meta/_journal.json` | `5` | `1` | `pg` | Sources: [integration-tests/drizzle2/sqlite/meta/_journal.json:1-12](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/sqlite/meta/_journal.json#L1-L12), [integration-tests/drizzle2/pg/meta/_journal.json:1-19](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/pg/meta/_journal.json#L1-L19), [integration-tests/drizzle2/singlestore/meta/_journal.json:1-13](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/singlestore/meta/_journal.json#L1-L13), [integration-tests/drizzle2/pg-proxy/first/meta/_journal.json:1-13](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/pg-proxy/first/meta/_journal.json#L1-L13) ### Proxy configurations and isolated entrysets Proxy integration tests use specialized journal directories such as `pg-proxy/first/meta/_journal.json` to validate driver-agnostic query and migration proxy layers. These proxy setups mirror standard PostgreSQL version schemas while restricting entrysets to initial baseline migrations. ```json { "version": "5", "dialect": "pg", "entries": [ { "idx": 0, "version": "5", "when": 1680271923328, "tag": "0000_puzzling_flatman", "breakpoints": true } ] } ``` Sources: [integration-tests/drizzle2/pg-proxy/first/meta/_journal.json:1-13](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/integration-tests/drizzle2/pg-proxy/first/meta/_journal.json#L1-L13) > [!NOTE] > SingleStore migration journals specify format version `1` and dialect identifier `singlestore`, differing from the version `5` format utilized across PostgreSQL and SQLite fixtures. > [!CAUTION] > Altering migration entry indices (`idx`) or timestamp values (`when`) within active journal fixtures causes migration parser validation checks to fail during test harness startup. ## In memory SQLite and embedded PostgreSQL execution ### SQLite driver instantiation across runtimes SQLite test harnesses instantiate local in-memory databases by invoking engine-specific constructors, such as `Database` from `better-sqlite3` or `Database` from `bun:sqlite`, paired with the `':memory:'` connection string. These client instances are passed directly to dialect-specific initialization helpers like `drizzleBetterSqlite3`, `drizzleBun`, `drizzleD1`, and `durableSqlite` to construct fully typed database instances for test execution and seeding utilities. ```typescript import Database from 'better-sqlite3'; import { Database as BunDatabase } from 'bun:sqlite'; import { drizzle as drizzleBetterSqlite3 } from '~/better-sqlite3/index.ts'; import { drizzle as drizzleBun } from '~/bun-sqlite/index.ts'; import { drizzle as drizzleD1 } from '~/d1/index.ts'; import { drizzle as durableSqlite } from '~/durable-sqlite/index.ts'; const client = new Database(':memory:'); const bunClient = new BunDatabase(':memory:'); declare const d1: D1Database; declare const durableSql: DurableObjectStorage; export const db = drizzleBetterSqlite3(client); export const bunDb = drizzleBun(bunClient); export const d1Db = drizzleD1(d1); export const durableSqliteDb = durableSqlite(durableSql); ``` Sources: [drizzle-orm/type-tests/sqlite/db.ts:1-16](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/sqlite/db.ts#L1-L16) > [!TIP] > SQLite seeding utilities support both standard table definitions and foreign key relational references using in-memory connections, allowing rapid fixture resets via `reset` and `seed` function calls. Sources: [drizzle-seed/type-tests/sqlite.ts:1-17](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-seed/type-tests/sqlite.ts#L1-L17) ### Embedded PGlite driver and session configuration Embedded PostgreSQL execution relies on the `PgliteDriver` class and the `@electric-sql/pglite` package to spin up zero-dependency PostgreSQL instances within test environments. The `drizzle` entry point handles multiple parameter overload signatures, accepting either an existing `PGlite` client instance, a connection string, a data directory path with options, or a configuration object containing `logger` and `cache` parameters. ```typescript export function drizzle< TSchema extends Record = Record, TClient extends PGlite = PGlite, >( ...params: | [] | [ TClient | string, ] | [ TClient | string, DrizzleConfig, ] | [ ( & DrizzleConfig & ({ connection?: (PGliteOptions & { dataDir?: string }) | string; } | { client: TClient; }) ), ] ): PgliteDatabase & { $client: TClient; } { if (params[0] === undefined || typeof params[0] === 'string') { const instance = new PGlite(params[0]); return construct(instance, params[1]) as any; } if (isConfig(params[0])) { const { connection, client, ...drizzleConfig } = params[0] as { connection?: PGliteOptions & { dataDir: string }; client?: TClient; } & DrizzleConfig; if (client) return construct(client, drizzleConfig) as any; if (typeof connection === 'object') { const { dataDir, ...options } = connection; const instance = new PGlite(dataDir, options); return construct(instance, drizzleConfig) as any; } const instance = new PGlite(connection); return construct(instance, drizzleConfig) as any; } return construct(params[0] as TClient, params[1] as DrizzleConfig | undefined) as any; } ``` Sources: [drizzle-orm/src/pglite/driver.ts:98-151](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/src/pglite/driver.ts#L98-L151) The internal `construct` function initializes the PostgreSQL dialect with optional casing configurations, parses user-provided loggers and schema definitions using `extractTablesRelationalConfig`, and attaches client reference properties `$client` and `$cache` to the resulting `PgliteDatabase` instance. ```typescript function construct = Record>( client: PgliteClient, config: DrizzleConfig = {}, ): PgliteDatabase & { $client: PgliteClient; } { const dialect = new PgDialect({ casing: config.casing }); let logger; if (config.logger === true) { logger = new DefaultLogger(); } else if (config.logger !== false) { logger = config.logger; } let schema: RelationalSchemaConfig | undefined; if (config.schema) { const tablesConfig = extractTablesRelationalConfig( config.schema, createTableRelationsHelpers, ); schema = { fullSchema: config.schema, schema: tablesConfig.tables, tableNamesMap: tablesConfig.tableNamesMap, }; } const driver = new PgliteDriver(client, dialect, { logger, cache: config.cache }); const session = driver.createSession(schema); const db = new PgliteDatabase(dialect, session, schema as any) as PgliteDatabase; ( db).$client = client; ( db).$cache = config.cache; if (( db).$cache) { ( db).$cache['invalidate'] = config.cache?.onMutate; } // ( db).$cache = { invalidate: ( config).cache?.onMutate }; // if (config.cache) { // for ( // const key of Object.getOwnPropertyNames(Object.getPrototypeOf(config.cache)).filter((key) => // key !== 'constructor' // ) // ) { // ( db).$cache[key as keyof typeof config.cache] = ( config).cache[key]; // } // } return db as any; } ``` Sources: [drizzle-orm/src/pglite/driver.ts:49-96](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/src/pglite/driver.ts#L49-L96) | Overload Signature | Primary Parameter Type | Description | | :--- | :--- | :--- | | Client or String | `TClient \| string \| undefined` | Instantiates a new `PGlite` with an optional connection string or data path. | | Configuration Object | `DrizzleConfig & (connection \| client)` | Configures PGlite using explicit connection options or a passed client instance. | | Mock Instance | `DrizzleConfig` via `drizzle.mock()` | Returns a mock database instance where `$client` is marked as unavailable. | Sources: [drizzle-orm/src/pglite/driver.ts:98-160](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/src/pglite/driver.ts#L98-L160) > [!WARNING] > Calling `drizzle.mock()` provides a database instance without an active client connection, returning the string literal `'\\$client is not available on drizzle.mock()'` for any access to the `$client` property. ## SingleStore connection pooling and query execution ### Connection pool instantiation and session setup SingleStore integration tests establish database connections and connection pools by utilizing the `mysql2/promise` package. The test harness creates a connection pool through the `createPool` function and passes the resulting pool object into the `drizzle` factory function to construct a typed SingleStore database instance for query execution. ```typescript import { createPool } from 'mysql2/promise'; import { drizzle } from '~/singlestore/index.ts'; const pool = createPool({}); export const db = drizzle(pool); ``` Sources: [drizzle-orm/type-tests/singlestore/db.ts:1-7](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/db.ts#L1-L7) The `drizzle` function accepts various configuration combinations, including passing the pool directly, providing a schema object alongside the pool, or supplying empty options configurations during initialization. ```typescript { drizzle(pool); drizzle(pool, { schema: {} }); drizzle(pool, { schema: {} }); drizzle(pool, {}); } ``` Sources: [drizzle-orm/type-tests/singlestore/db.ts:8-13](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/db.ts#L8-L13) > [!NOTE] > SingleStore database instances support optional schema definitions passed via the initialization configuration object to bind tables directly to targeted named schemas. ### Dialect query lifecycle and locking modifiers Query execution test suites validate complex join operations, subqueries, and table aliasing across the SingleStore dialect. Queries support explicit locking clauses such as `.for('update')` and `.for('share')`, with configuration options including `noWait` and `skipLocked` flags. ```typescript await db.select().from(users).for('update'); await db.select().from(users).for('share', { skipLocked: true }); await db.select().from(users).for('update', { noWait: true }); ``` Sources: [drizzle-orm/type-tests/singlestore/select.ts:615-617](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/select.ts#L615-L617) | Locking Clause | Modifier Option | Description | | :--- | :--- | :--- | | `for('update')` | None | Locks selected rows for update operations. | | `for('share')` | `{ skipLocked: true }` | Shares selected rows while skipping locked records. | | `for('update')` | `{ noWait: true }` | Attempts to lock rows for update without waiting for locks to release. | Sources: [drizzle-orm/type-tests/singlestore/select.ts:615-617](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/select.ts#L615-L617) > [!CAUTION] > Combining both `noWait` and `skipLocked` within the same locking modifier options object triggers a type-level compilation error to prevent conflicting locking behaviors. ```typescript /* await db .select() .from(users) // @ts-expect-error - can't use both skipLocked and noWait .for('share', { noWait: true, skipLocked: true }); ``` Sources: [drizzle-orm/type-tests/singlestore/select.ts:619-623](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-orm/type-tests/singlestore/select.ts#L619-L623) ## Ecosystem package test harnesses ### Schema validation and seeding test parameters Test configuration parity across ecosystem packages is maintained through dedicated Vitest runner settings in `drizzle-zod`, `drizzle-typebox`, `drizzle-valibot`, `drizzle-arktype`, and `drizzle-seed`. Schema validator packages exclude runtime bun-specific test folders (`tests/bun/**/*`) while configuring test timeouts to `100000` milliseconds, hook timeouts to `100000` milliseconds, and running tests with `isolate: false` and `singleThread: true` via thread pool options. ```typescript test: { include: [ 'tests/**/*.test.ts', ], exclude: [ 'tests/bun/**/*', ], typecheck: { tsconfig: 'tsconfig.json', }, testTimeout: 100000, hookTimeout: 100000, isolate: false, poolOptions: { threads: { singleThread: true, }, }, }, ``` Sources: [drizzle-zod/vitest.config.ts:5-23](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-zod/vitest.config.ts#L5-L23) | Package Configuration | Test Isolation (`isolate`) | Thread Mode (`singleThread`) | Test Timeout (ms) | Excluded Patterns | | :--- | :--- | :--- | :--- | :--- | | `drizzle-zod` | `false` | `true` | `100000` | `tests/bun/**/*` | | `drizzle-typebox` | `false` | `true` | `100000` | `tests/bun/**/*` | | `drizzle-valibot` | `false` | `true` | `100000` | `tests/bun/**/*` | | `drizzle-arktype` | `false` | `true` | `100000` | `tests/bun/**/*` | | `drizzle-seed` | `true` | `true` | `100000` | None | Sources: [drizzle-seed/vitest.config.ts:4-24](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-seed/vitest.config.ts#L4-L24), [drizzle-arktype/vitest.config.ts:5-23](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-arktype/vitest.config.ts#L5-L23), [drizzle-valibot/vitest.config.ts:5-23](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-valibot/vitest.config.ts#L5-L23), [drizzle-typebox/vitest.config.ts:5-23](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-typebox/vitest.config.ts#L5-L23), [drizzle-zod/vitest.config.ts:5-23](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/drizzle-zod/vitest.config.ts#L5-L23) > [!NOTE] > `drizzle-seed` enforces strict test isolation (`isolate: true`) across postgres, mysql, and sqlite test directories while explicitly setting `maxWorkers: 1` and `fileParallelism: false`. ### Linting tool verification and path resolution The `eslint-plugin-drizzle` test suite relies on a simplified Vitest setup enabling global test APIs and excluding `**/dist/**` build output paths. Meanwhile, parser configurations across `drizzle-kit`, `drizzle-arktype`, `drizzle-valibot`, `drizzle-typebox`, and `drizzle-zod` utilize `vite-tsconfig-paths` plugins to map internal path aliases directly against local `tsconfig.json` definitions. ```typescript import { defineConfig } from 'vitest/config'; export default defineConfig({ test: { globals: true, exclude: ['**/dist/**'], }, ``` Sources: [eslint-plugin-drizzle/vitest.config.ts:1-7](https://github.com/blade47/drizzle-orm/blob/48e5406027103a9fca6eb66417187c4a8b5c6aa3/eslint-plugin-drizzle/vitest.config.ts#L1-L7) > [!WARNING] > Omitting `vite-tsconfig-paths` plugin registration in ecosystem package test files causes module resolution failures when test suites import internal workspace dependencies using path aliases. ## Related - [Monorepo Build Pipeline](https://www.doc0.dev/docs/e1b68fed-3c4e-4c95-b2ba-ebf050f78025/technical/testing-and-tooling/monorepo-build-pipeline) - [Type System Verification](https://www.doc0.dev/docs/e1b68fed-3c4e-4c95-b2ba-ebf050f78025/technical/testing-and-tooling/type-system-verification) ## Sitemap See the full [sitemap](https://www.doc0.dev/docs/e1b68fed-3c4e-4c95-b2ba-ebf050f78025/llms.txt) for all pages in this wiki.