refactor: make overloads, not unions

README.md

@@ -4,7 +4,7 @@ This package provides official storage adapters for Telegraf v4.12+ sessions [[s
 
 > ⚠️ Very Important!
 >
-> Read one of the following sections before using this module. You're not meant to import the default route!
+> Read one of the following sections before using this module. You're not meant to import the default path!
 
 An in-memory session module is bundled with Telegraf. The following modules are available here:
 
@@ -27,14 +27,18 @@ Usage is pretty straightforward:
 ```TS
 import { Redis } from "@telegraf/session/redis";
 
-const store = Redis({ url: "redis://127.0.0.1:6379" });
+const store = Redis({
+	url: "redis://127.0.0.1:6379",
+});
 
 const bot = new Telegraf(token, opts);
 bot.use(session({ store }));
 
 // the rest of your bot
 ```
 
+To reuse an existing Redis client, use `Redis({ client })` instead.
+
 ## MongoDB
 
 Install the official MongoDB driver alongside this module.
@@ -48,14 +52,19 @@ Usage is pretty straightforward:
 ```TS
 import { Mongo } from "@telegraf/session/mongodb";
 
-const store = Mongo({ url: "mongodb://127.0.0.1:27017", database: "telegraf-bot" });
+const store = Mongo({
+	url: "mongodb://127.0.0.1:27017",
+	database: "telegraf-bot",
+});
 
 const bot = new Telegraf(token, opts);
 bot.use(session({ store }));
 
 // the rest of your bot
 ```
 
+To reuse an existing MongoDB client, use `Mongo({ client })` instead.
+
 ## SQLite
 
 Install the Better-SQLite3 driver and types alongside this module.
@@ -70,14 +79,18 @@ Usage is pretty straightforward:
 ```TS
 import { SQLite } from "@telegraf/session/sqlite";
 
-const store = SQLite({ filename: "./telegraf-sessions.sqlite" });
+const store = SQLite({
+	filename: "./telegraf-sessions.sqlite",
+});
 
 const bot = new Telegraf(token, opts);
 bot.use(session({ store }));
 
 // the rest of your bot
 ```
 
+To reuse an existing Better-SQLite3 database instance, use `SQLite({ database })` instead.
+
 ## PostgreSQL
 
 Install the 'pg' PostgreSQL driver and types alongside this module.
@@ -105,6 +118,8 @@ bot.use(session({ store }));
 // the rest of your bot
 ```
 
+To reuse an existing pg pool, use `Postgres({ pool })` instead.
+
 ## MySQL / MariaDB
 
 Install the 'mysql2' MySQL driver alongside this module.
@@ -131,8 +146,10 @@ bot.use(session({ store }));
 // the rest of your bot
 ```
 
+To reuse an existing MySQL2 pool, use `MySQL({ pool })` instead.
+
 ## Background
 
-Since [telegraf#1372](https://github.com/telegraf/telegraf/issues/1372), it has been known that all asynchronous session middleware have been prone to race-conditions. This was addressed in [telegraf#1713](https://github.com/telegraf/telegraf/pull/1713), but third-party session middleware continue to be affected. Since Telegraf 1.12.0, it's recommended that third-party middleware only provide the store parameter for session, instead of implementing session themselves. This way, they can take advantage of the safety provided by Telegraf's builtin session. Of course, if your plugin has an exceptional case, it may need to implement a middleware.
+Since [telegraf#1372](https://github.com/telegraf/telegraf/issues/1372), it has been known that all asynchronous session middleware have been prone to race-conditions. This was addressed in [telegraf#1713](https://github.com/telegraf/telegraf/pull/1713), but third-party session middleware continue to be affected. Since Telegraf 1.12.0, it's recommended that third-party plugins only provide the store parameter for session, instead of implementing session themselves. This way, they can take advantage of the safety provided by Telegraf's builtin session. Of course, if your plugin has an exceptional usecase, it may need to implement its own middleware.
 
-To begin to solve this problem, we officially maintain the 5 most common storage backends. This package is considered beta, and while it appears stable, it may have changes and bugfixes before a semver stable release.
+To begin to solve this problem, we officially maintain the 5 most common storage backends. This package is considered beta, and may have minor breaking changes and bugfixes before a semver stable release. Feedback is welcome via issues and in the group: [TelegrafJSChat](https://t.me/TelegrafJSChat)

mongodb.ts

@@ -32,10 +32,10 @@ interface ExistingClientOpts {
 	onInitError?: (err: unknown) => void;
 }
 
-export type Opts = NewClientOpts | ExistingClientOpts;
-
 /** @unstable */
-export const Mongo = <Session>(opts: Opts): SessionStore<Session> => {
+export function Mongo<Session>(opts: NewClientOpts): SessionStore<Session>;
+export function Mongo<Session>(opts: ExistingClientOpts): SessionStore<Session>;
+export function Mongo<Session>(opts: NewClientOpts | ExistingClientOpts): SessionStore<Session> {
 	interface SessionDoc {
 		key: string;
 		session: Session;
@@ -68,4 +68,4 @@ export const Mongo = <Session>(opts: Opts): SessionStore<Session> => {
 			await collection.deleteOne({ key });
 		},
 	};
-};
+}

mysql.ts

@@ -1,6 +1,7 @@
 import { MysqlDialect } from "kysely";
 import { createPool, Pool, PoolOptions } from "mysql2";
 import { KyselyStore } from "./kysely";
+import { SessionStore } from "./types";
 
 interface NewPoolOpts {
 	host?: string | undefined;
@@ -31,11 +32,11 @@ interface ExistingPoolOpts {
 	onInitError?: (err: unknown) => void;
 }
 
-export type Opts = NewPoolOpts | ExistingPoolOpts;
-
 /** @unstable */
-export const MySQL = <Session>(opts: Opts) =>
-	KyselyStore<Session>({
+export function MySQL<Session>(opts: NewPoolOpts): SessionStore<Session>;
+export function MySQL<Session>(opts: ExistingPoolOpts): SessionStore<Session>;
+export function MySQL<Session>(opts: NewPoolOpts | ExistingPoolOpts) {
+	return KyselyStore<Session>({
 		config:
 			"pool" in opts
 				? { dialect: new MysqlDialect({ pool: opts.pool }) }
@@ -54,3 +55,4 @@ export const MySQL = <Session>(opts: Opts) =>
 		table: opts.table,
 		onInitError: opts.onInitError,
 	});
+}

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@telegraf/session",
-	"version": "2.0.0-beta.2",
+	"version": "2.0.0-beta.3",
 	"description": "Session store adapters for Telegraf",
 	"main": "./memory.js",
 	"scripts": {

pg.ts

@@ -1,6 +1,7 @@
 import { PostgresDialect } from "kysely";
 import { Pool, PoolConfig } from "pg";
 import { KyselyStore } from "./kysely";
+import { SessionStore } from "./types";
 
 interface NewPoolOpts {
 	host?: string | undefined;
@@ -31,11 +32,11 @@ interface ExistingPoolOpts {
 	onInitError?: (err: unknown) => void;
 }
 
-export type Opts = NewPoolOpts | ExistingPoolOpts;
-
 /** @unstable */
-export const Postgres = <Session>(opts: Opts) =>
-	KyselyStore<Session>({
+export function Postgres<Session>(opts: NewPoolOpts): SessionStore<Session>;
+export function Postgres<Session>(opts: ExistingPoolOpts): SessionStore<Session>;
+export function Postgres<Session>(opts: NewPoolOpts | ExistingPoolOpts) {
+	return KyselyStore<Session>({
 		config:
 			"pool" in opts
 				? { dialect: new PostgresDialect({ pool: opts.pool }) }
@@ -54,3 +55,4 @@ export const Postgres = <Session>(opts: Opts) =>
 		table: opts.table,
 		onInitError: opts.onInitError,
 	});
+}

redis.ts

@@ -25,10 +25,10 @@ interface ExistingClientOpts {
 	prefix?: string;
 }
 
-export type Opts = NewClientOpts | ExistingClientOpts;
-
 /** @unstable */
-export const Redis = <Session>(opts: Opts): SessionStore<Session> => {
+export function Redis<Session>(opts: NewClientOpts): SessionStore<Session>;
+export function Redis<Session>(opts: ExistingClientOpts): SessionStore<Session>;
+export function Redis<Session>(opts: NewClientOpts | ExistingClientOpts): SessionStore<Session> {
 	let client: Client;
 	if ("client" in opts) client = opts.client;
 	else client = createClient({ ...opts.config, url: opts.url });
@@ -52,4 +52,4 @@ export const Redis = <Session>(opts: Opts): SessionStore<Session> => {
 			return await client.del(prefix + key);
 		},
 	};
-};
+}

sqlite.ts

@@ -2,6 +2,7 @@ import { SqliteDialect } from "kysely";
 import { Database as Db, Options } from "better-sqlite3";
 import { KyselyStore } from "./kysely";
 import Database = require("better-sqlite3");
+import { SessionStore } from "./types";
 
 interface NewDatabaseOpts {
 	/** Filename to use for SQLite sessions. */
@@ -25,14 +26,15 @@ interface ExistingDatabaseOpts {
 	onInitError?: (err: unknown) => void;
 }
 
-export type Opts = NewDatabaseOpts | ExistingDatabaseOpts;
-
 /** @unstable */
-export const SQLite = <Session>(opts: Opts) =>
-	KyselyStore<Session>({
+export function SQLite<Session>(opts: NewDatabaseOpts): SessionStore<Session>;
+export function SQLite<Session>(opts: ExistingDatabaseOpts): SessionStore<Session>;
+export function SQLite<Session>(opts: NewDatabaseOpts | ExistingDatabaseOpts) {
+	return KyselyStore<Session>({
 		config:
 			"database" in opts
 				? { dialect: new SqliteDialect({ database: opts.database }) }
 				: { dialect: new SqliteDialect({ database: new Database(opts.filename, opts.config) }) },
 		onInitError: opts.onInitError,
 	});
+}