npm package: @galactic-squidge/prisma-session-store
Description: Prisma express-session store
Author: Krispin Leydon
Latest version: 3.2.1-rc

# prisma-session-store

> [!NOTE]  
> This project is a fork of the [original](https://github.com/kleydon/prisma-session-store) with the sole purpose of implementing the "dispose" option, which I leaned was either not implemented or removed from the codebase. It is otherwise completely untouched.

An [express](https://github.com/expressjs) session store implementation for the [Prisma ORM](https://github.com/prisma).

Want the flexibility and scalability of a Prisma GraphQL data layer, along with the optionality and maturity of the Express ecosystem - but concerned about [JWT](https://jwt.io) or [Paseto](https://paseto.io) tokens for session management (see cautions posted [here](https://paragonie.com/blog/2017/03/jwt-json-web-tokens-is-bad-standard-that-everyone-should-avoid), [here](http://cryto.net/%7Ejoepie91/blog/2016/06/19/stop-using-jwt-for-sessions-part-2-why-your-solution-doesnt-work/), [here](https://techblog.bozho.net/using-jwt-sessions/), [here](https://news.ycombinator.com/item?id=17877332), and [here](https://developer.okta.com/blog/2017/08/17/why-jwts-suck-as-session-tokens))?

`prisma-session-store` simplifies access to tried-and-true express session management via Prisma's database client.

Based on: [memorystore](https://github.com/roccomuso/memorystore), by [roccomuso](https://github.com/roccomuso)

## Usage

### JavaScript (CommonJS)

```js

const expressSession = require('express-session');
const { PrismaSessionStore } = require('@galactic-squidge/prisma-session-store');
const { PrismaClient } = require('@prisma/client');

...

app.use(
  expressSession({
    cookie: {
     maxAge: 7 * 24 * 60 * 60 * 1000 // ms
    },
    secret: 'a santa at nasa',
    resave: true,
    saveUninitialized: true,
    store: new PrismaSessionStore(
      new PrismaClient(),
      {
        checkPeriod: 2 * 60 * 1000,  //ms
        dbRecordIdIsSessionId: true,
        dbRecordIdFunction: undefined,
      }
    )
  })
);

...

```

### TypeScript

```ts
import expressSession from 'express-session';
import { PrismaSessionStore } from '@galactic-squidge/prisma-session-store';
import  { PrismaClient } from '@prisma/client';
...

app.use(
  expressSession({
    cookie: {
     maxAge: 7 * 24 * 60 * 60 * 1000 // ms
    },
    secret: 'a santa at nasa',
    resave: true,
    saveUninitialized: true,
    store: new PrismaSessionStore(
      new PrismaClient(),
      {
        checkPeriod: 2 * 60 * 1000,  //ms
        dbRecordIdIsSessionId: true,
        dbRecordIdFunction: undefined,
      }
    )
  })
);

...
```

## Setup

### Install

Install `@galactic-squidge/prisma-session-store` (and `express-session`, if not already installed):

#### NPM

`$ npm install @galactic-squidge/prisma-session-store express-session`

#### yarn

`$ yarn add @galactic-squidge/prisma-session-store express-session`

### Prisma

#### Model

From your **prisma.schema** file, include a session model:

```prisma
model Session {
  id        String   @id
  sid       String   @unique
  data      String   @db.MediumText  // MediumText may be needed for MySql
  expiresAt   DateTime
}
```

Don't forget to run `npx prisma generate` to generate your PrismaClient.

#### Types - GraphQL Nexus

If you are using [@nexus/schema](https://www.npmjs.com/package/@nexus/schema) you can define your Session type:

```js
...

{
  name: 'Session',
  definition(t) {
    t.model.id();
    t.model.sid();
    t.model.data();
    t.model.expiresAt();
  }
}
...

```

#### Database

If you are using Prisma's migrations you can simply run `prisma migrate dev` to migrate your database.
If you are using something other then `prisma` then you will need to manage the migrations yourself and you check the [Prisma Documentation](https://www.prisma.io/docs/getting-started/setup-prisma/start-from-scratch-sql-typescript-postgres#create-database-tables-with-sql) on the subject if you need help.

#### MySQL

If you are using MySQL as your datasource provider you may also need change the type of your data column to TEXT:

```sql
USE your-database
ALTER TABLE Session MODIFY data TEXT;
```

Prisma `String` properties are mapped to `VARCHAR(191)` by default. Session data can be larger than 191 characters so updating the type to `TEXT` prevents errors when creating and updating sessions. If you know your session data will not exceed 191 characters you can skip this step or if you know your maximum size you can use `VARCHAR(YOUR_MAX_SIZE)`

If you are using a version of Prisma that supports [migrating with native types](https://github.com/prisma/prisma/issues/4330) you can use a type annotation in your `schema.prisma` file instead of manually modifying your data column.

## Upgrading from versions following `3.1.9`

Concurrent calls to `set()` and concurrent calls to `touch()` having the same session id are now disallowed by default, as a work-around to address [issue 88](https://github.com/kleydon/prisma-session-store/issues/88). (This issue may surface when a browser is loading multiple resources for a page in parallel). The issue may be limited to SQLite, but hasn't been isolated; `express-session` or `prisma` may be implicated. If necessary, you can prevent the new default behavior, and re-enable concurrent calls having the same session id, by setting one or both of: `enableConcurrentSetInvocationsForSameSessionID`, `enableConcurrentTouchInvocationsForSameSessionID` to `true`; see below.

## Migrating from versions following `2.0.0`

Following version `2.0.0`, the `Session` `expires` field was renamed to `expiresAt` to match Prisma's naming convention for date fields.

## Migrating from versions prior to `1.0.0`

In `1.0.0` the public API of this library was reworked. Previously the default export that was a
factory to build the `PrismaSessionStore` class. In `1.0.0` a named export of the class
`PrismaSessionStore` was put in place of the default export. So after updating you will need to
change your import and remove your call to the factory.

### JavaScript

Before

```js
const PrismaSessionStore = require('@galactic-squidge/prisma-session-store')(
  expressSession
);
```

After

```js
const { PrismaSessionStore } = require('@galactic-squidge/prisma-session-store');
```

### TypeScript

Before

```ts
import prismaSessionStore from '@galactic-squidge/prisma-session-store';

const PrismaSessionStore = prismaSessionStore(expressSession);
```

After

```ts
import { PrismaSessionStore } from '@galactic-squidge/prisma-session-store';
```

## Options

- `dbRecordIdIsSessionId` A flag indicating to use the session ID as the Prisma Record ID

- `dbRecordIdFunction` A function to generate the Prisma Record ID for a given session ID

Note: If both dbRecordIdFunction and dbRecordIdIsSessionId are undefined then a random
CUID will be used instead.

- `checkPeriod` Interval, in ms, at which PrismaSessionStore will automatically remove expired sessions. Disabled by default; set to something reasonable.

- `ttl` "Time to live", in ms; defines session expiration time. Defaults to session.maxAge (if set), or one day (if not set). May alternatively be set to a function, of the form `(options, session, sessionID) => number`.

- `dispose` Called on sessions when they are dropped. Handy if you want to close file descriptors or do other cleanup tasks when sessions are no longer accessible. Called with `key, value`. It's called _before_ actually removing the item from the internal cache, so if you want to immediately put it back in, you'll have to do that in a `nextTick` or `setTimeout` callback or it won't do anything.

- `stale` By default, if you set a `maxAge`, it'll only actually pull stale items out of the cache when you `get(key)`. (That is, it's not pre-emptively doing a `setTimeout` or anything.) If you set `stale:true`, it'll return the stale value before deleting it. If you don't set this, then it'll return `undefined` when you try to get a stale entry, as if it had already been deleted.

- `noDisposeOnSet` By default, if you set a `dispose()` method, then it'll be called whenever a `set()` operation overwrites an existing key. If you set this option, `dispose()` will only be called when a key falls out of the cache, not when it is overwritten.

- `serializer` An object containing `stringify` and `parse` methods compatible with Javascript's `JSON` to override the serializer used.

- `sessionModelName` By default, the session table is called `sessions` and the associated model is `session`, but you can provide a custom model name. This should be the camelCase version of the name.

Five new options were added, apart from the work that was already done by [memorystore](https://github.com/roccomuso/memorystore), two of them relate to logging and allow you to inject your own logger object giving you flexibility to log outputs to something like NestJS or whenever you would like, even saving them to disk if that's what you want. And the third is used for testing to round the TTL so that it can be compared do another generated ttl during the assertion.

- `logger` Where logs should be outputted to, by default `console`. If set to `false` then logging will be disabled

- `loggerLevel` Determines which logging methods to enable, by default `error` only

- `roundTTL` the amount of milliseconds to round down the TTL so that it will match another TTL generated later.
  Mostly used for test stability.

- `enableConcurrentSetInvocationsForSameSessionID` and `enableConcurrentTouchInvocationsForSameSessionID`. Since v3.1.9, concurrent calls to set() and touch() for the same session id have been disabled, as a work-around for an issue that users have been experiencing (see [Issue 88](https://github.com/kleydon/prisma-session-store/issues/88)). This issue may occur when a browser is loading multiple resources for a page in parallel. The issue may be limited to use of SQLite, but has not yet been isolated; `express-session` or `prisma` may be implicated. If necessary, you can prevent this default behavior and re-enable concurrent calls having the same session id by setting one or both of these variables to `true`.

## Methods

`prisma-session-store` implements all the **required**, **recommended** and **optional** methods of the [express-session](https://github.com/expressjs/session#session-store-implementation) store, plus a few more:

- `startInterval(onIntervalError?: (err: unknown) => void)` and `stopInterval()` methods to start/clear the automatic check for expired. (The optional `onError()` callback that fires if/when the interval's `prune()` function throws an error.)
- `prune()` that you can use to manually remove only the expired entries from the store.
- `shutdown()` that can be used to stop any intervals and disconnect from prisma.

## Author

Krispin Leydon ([kleydon](https://github.com/kleydon)), originally based on [memorystore](https://github.com/roccomuso/memorystore), by [roccomuso](https://github.com/roccomuso), refactored to TypeScript (with extensive improvement) by [wSedlacek](https://github.com/wSedlacek)

## License

MIT