feat(subscriptions): pg-pubsub module (#400)

packages/graphile-build/src/SchemaBuilder.d.ts

@@ -18,7 +18,7 @@ import { EventEmitter } from "events";
 type mixed = {} | string | number | boolean | undefined | null;
 
 export interface Options {
-  [str: string]: mixed;
+  [str: string]: any;
 }
 
 export interface Plugin {

packages/lds/package.json

@@ -6,6 +6,7 @@
   "scripts": {
     "db:init": "dropdb --if-exists lds_test && createdb lds_test && psql -X1v ON_ERROR_STOP=1 -v VERBOSITY=verbose -f __tests__/schema.sql lds_test",
     "test": "npm run db:init && jest -i",
+    "tslint": "prettier --list-different 'src/**/*' && tslint --config ../../tslint.json --project tsconfig.json",
     "prepack": "tsc",
     "watch": "tsc --watch"
   },

packages/pg-pubsub/.gitignore

@@ -0,0 +1 @@
+/dist/

packages/pg-pubsub/LICENSE.md

@@ -0,0 +1,24 @@
+# The MIT License (MIT)
+
+Copyright © `2019` Benjie Gillam
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the “Software”), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.

packages/pg-pubsub/README.md

@@ -0,0 +1,59 @@
+# @graphile/pg-pubsub
+
+This PostGraphile [server
+plugin](https://www.graphile.org/postgraphile/plugins/) provides a `pubsub`
+instance to [schema
+plugins](https://www.graphile.org/postgraphile/extending/) that uses
+PostgreSQL `LISTEN`/`NOTIFY` to provide realtime features.
+
+Also adds support for `@pgSubscriptions` directive to easily define your own
+subscriptions using LISTEN/NOTIFY with `makeExtendSchemaPlugin`; and adds the
+`--simple-subscriptions` feature which, when enabled, adds a simple `listen`
+subscription field to your GraphQL API.
+
+It's intended that you use this plugin as a provider of realtime data to
+other plugins which can use it to add subscription fields to your API.
+
+For full documentation, see: https://www.graphile.org/postgraphile/subscriptions/
+
+## Usage
+
+CLI:
+
+```
+yarn add @graphile/pg-pubsub
+
+postgraphile \
+  --plugins @graphile/pg-pubsub \
+  --subscriptions \
+  --simple-subscriptions \
+  -c postgres:///mydb
+```
+
+Library:
+
+```js
+const express = require("express");
+const { postgraphile, makePluginHook } = require("postgraphile");
+const { default: PgPubsub } = require("@graphile/pg-pubsub");
+
+const pluginHook = makePluginHook([PgPubsub]);
+
+const postgraphileOptions = {
+  pluginHook,
+  subscriptions: true, // Enable PostGraphile websocket capabilities
+  simpleSubscriptions: true, // Add the `listen` subscription field
+  websocketMiddlewares: [
+    // Add whatever middlewares you need here, note that they should only
+    // manipulate properties on req/res, they must not sent response data. e.g.:
+    //
+    //   require('express-session')(),
+    //   require('passport').initialize(),
+    //   require('passport').session(),
+  ],
+};
+
+const app = express();
+app.use(postgraphile(databaseUrl, "app_public", postgraphileOptions));
+app.listen(parseInt(process.env.PORT, 10) || 3000);
+```