mysql-memory-server
v1.8.1
Published
Spin up an ephemeral MySQL database from your JavaScript code
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MySQL Memory Server
This package allows you to create ephemeral MySQL databases from JavaScript and/or TypeScript code and also the CLI, great for testing, CI, and learning MySQL. When creating a new database, if the version selected is not installed on the system, the binary is downloaded from MySQL's CDN (cdn.mysql.com)
You can run multiple MySQL databases with this package at the same time. Each database will use a random free port. The databases will automatically shutdown when the JS runtime process exits. A stop()
method is also provided to stop each database instance.
Installation
Download with your package manager of choice. The package name is mysql-memory-server
. If using npm, the install command will be npm install mysql-memory-server
.
Requirements
- Node.js >=16.6.0 or Bun >= 1.0.0
- macOS 13+, Windows, or Linux (This package is only tested on Ubuntu 20.04, 22.04, 24.04, and Fedora 40. Other Linux distributions may or may not work at this time.)
Requirements for downloaded MySQL versions
The following requirements only apply if you intend to have mysql-memory-server
download a version of MySQL to use instead of using an already installed version of MySQL on the system:
Requirements for Windows:
Microsoft Visual C++ 2019 Redistributable Package
needs to be installed
Requirements for Linux:
- The
libaio1
orlibaio1t64
package needs to be installed - If
libaio1
is not available butlibaio1t64
is, theldconfig
command needs to be available to run - The
tar
package needs to be installed
Currently supported MySQL versions
- If using the system installed MySQL server: 8.0.20 and newer
- If not using the system installed MySQL server: 8.0.39, 8.0.40, 8.1.0, 8.2.0, 8.3.0, 8.4.2, 8.4.3, 9.0.1, 9.1.0
Example Usage - Application Code
This package supports both ESM and CJS so you can use import or require.
import { createDB } from 'mysql-memory-server';
import sql from 'mysql2/promise'
// Create a new database with default options
const db = await createDB()
//OR
//Create a new database with custom options set
const db = await createDB({
// see Options below for the options you can use in this object and their default values
// for example:
version: '8.4.x'
})
// Connect to the new database with the port provided
// The database is initialized with an empty password so use an empty string for the password
const connection = await sql.createConnection({
host: '127.0.0.1',
user: db.username,
port: db.port,
database: db.dbName,
password: ''
})
// Run your queries here
// ...
// Once done, disconnect from the database
await connection.end()
// Then stop the database
await db.stop()
MySQL database initialization can take some time. If you run into a "Timeout exceeded" error with your tests, the timeout should be extended. If using Jest, information about how to do this can be found here: https://jestjs.io/docs/jest-object#jestsettimeouttimeout
Example Usage - CLI
# Options are added by doing --{optionName} {optionValue}
# See Options below for the options you can use with this package
npx mysql-memory-server@latest --version 8.4.x
Documentation
createDB(options: ServerOptions): Promise<MySQLDB>
On success, resolves with an object with the following properties:
port: number
The port that the MySQL database is listening onxPort: number
The port that MySQLX is listening ondbName: string
The database that was created on database initializationusername: string
The name of the user to use to login to the databasesocket: string
If on Windows, this is the name of the named pipe that MySQL is listening on. If not on Windows, this is the path to the socket that MySQL is listening on.xSocket: string
If on Windows, this is the name of the named pipe that the MySQL X Plugin is listening on. If not on Windows, this is the path that the MySQL X Plugin is listening on.mysql: {version: string, versionIsInstalledOnSystem: boolean}
An object with two properties.version
is the version of MySQL used to create the database.versionIsInstalledOnSystem
will be true if the MySQL version used is already installed on the system and false if the version had to be downloaded from MySQL's CDN.stop: () => Promise<void>
The method to stop the database. The returned promise resolves when the database has successfully stopped.
Options:
All options are not required to be set. Using undefined
as a value will use the option's default value.
version: string
Default: undefined
Description: Version of MySQL to use for the database. Uses semver for getting the version, so valid semver versions are allowed. For example, 8.x
is a valid version and will use the latest 8.x MySQL version.
If left undefined:
- If the system has MySQL installed, the system-installed version will be used. If the installed version is not supported by this package (currently <8.0.20), an error will be thrown unless
ignoreUnsupportedSystemVersion
is set totrue
. - If the system does not have MySQL installed, the latest version of MySQL in the
versions.json
file in this package will be downloaded.
If defined:
If the version is 8.0.19 or older, an error will be thrown as this package does not currently support those versions of MySQL.
If the desired version of MySQL is installed on the system, the installed version will be used. Otherwise the selected version will be downloaded from the MySQL CDN as long as it can be found in the
versions.json
file. If it cannot be found in that file, an error will be thrown.dbName: string
Default: "dbdata"
Description: The name of the database to create when initializing MySQL. You'd use this name to connect to the database.
logLevel: "LOG" | "WARN" | "ERROR"
Default: "ERROR"
Description: Log level for this package. If "ERROR" is used, only errors from this package will show up in the console. If "WARN" is used, warnings and errors from this package will show up in the console. If "LOG" is used, every log from this package will show up in the console.
portRetries: number
Default: 10
Description: Number of times to try connecting MySQL to a randomly generated port before giving up. According to the MySQL Documentation if port 0 is used as the MySQL server port, the default value (3306) will be used. To get around this, a random number between 1025 - 65535 (inclusive) is generated and used for the database's port. If MySQL cannot successfully listen on a randomly generated port after portRetries
then the createDB()
promise is rejected. A warning is created when MySQL tries connecting to a port that is already in use. This option only applies for the MySQL port if the MySQL port is not explicitly set or if it's set to 0. This option also only applies for the MySQL X port if the MySQL X port is not explicitly set or if it's set to 0.
downloadBinaryOnce: boolean
Default: true
Description: If set to true, all versions requested that need to be downloaded from MySQL's CDN will be downloaded once and will stay on the system after the database stops. If set to false, the binaries that need to be downloaded will be downloaded for each database creation and will be deleted when the database is stopped.
Use false
to save disk space after the databases have been stopped, or use true
to save bandwidth
lockRetries: number
Default: 1,000
Description: If downloadBinaryOnce
is set to true
, lockRetries
is the number of times to check to see if the lock for the binary has been released (meaning it has been successfully downloaded and extracted). If the number of retries exceeds lockRetries
, the createDB()
promise gets rejected. This option is also used for the number of times to check to see if the lock for libaio has been released (only on Linux distros that use libaio1t64 instead of libaio1)
lockRetryWait: number
Default: 1,000
Description: If downloadBinaryOnce
is set to true
and/or on Linux distros that use libaio1t64 instead of libaio1, lockRetryWait
is the number of milliseconds to wait before checking if the lock has been released.
username: string
Default: root
Description: The username of the user that is used to login to the database.
port: number
Default: 0
Description: The port that the database will listen on. If set to 0, a randomly generated port is used.
xPort: number
Default: 0
Description: The port that the MySQL X Plugin will listen on. If set to 0, a randomly generated port is used.
ignoreUnsupportedSystemVersion: boolean
Default: false
Description: This option only applies if the system-installed MySQL version is lower than the oldest supported MySQL version for this package (8.0.20) and the version
option is not defined. If set to true
, this package will use the latest version of MySQL instead of the system-installed version. If false
, the package will throw an error.
downloadRetries: number
Default: 3
Description: The number of times to try to download a MySQL binary before giving up and rejecting the createDB()
promise.
initSQLString: string
Default: ""
Description: A string with MySQL queries to run before the database starts to accept connections. This option can be used for things like initialising tables without having to first connect to the database to do that. The queries in the string get executed after mysql-memory-server
's queries run. Uses the --init-file
MySQL server option under the hood. Learn more at the --init-file MySQL Documentation
The internal queries that are ran before the queries in initSQLString
are renaming the user from root
to the username specified in the username
option if it's set, and creating a database with the name from the dbName
option.
arch: "arm64" | "x64"
Default: process.arch
Description: The MySQL binary architecture to execute. MySQL does not offer server builds for Windows on ARM, so to get this package working on Windows on ARM, set the arch option to "x64" and Windows will emulate MySQL.
:warning: Internal Options :warning:
The following options are only meant for internal use (such as for testing this package or the internals for running this package via the CLI). Their behaviour may change or they may get removed between major/minor/patch versions and they are not to be considered stable. The options below will not follow Semantic Versioning so it is advised to not use them.
_DO_NOT_USE_deleteDBAfterStopped: boolean
Default: true
Description: Changes whether or not the database will be deleted after it has been stopped. If set to true
, the database WILL be deleted after it has been stopped.
_DO_NOT_USE_dbPath: string
Default: TMPDIR/mysqlmsn/dbs/UUID
(replacing TMPDIR with the OS temp directory and UUID with a UUIDv4 without seperating dashes).
Description: The folder to store database-related data in
_DO_NOT_USE_binaryDirectoryPath: string
Default: TMPDIR/mysqlmsn/binaries
(replacing TMPDIR with the OS temp directory)
Description: The folder to store the MySQL binaries when they are downloaded from the CDN.
_DO_NOT_USE_cli: boolean
Default: false
if the package is not being executed via the CLI and true
if it is.
Description: If set to true
, this enables certain CLI-only functionality. For example, when ran by the CLI, logging a message to the console when a shutdown signal (like CTRL + C) has been received and the MySQL database is shutting down and getting deleted.