feat(server): websockets support (#986)

* Websocket subscriptions support

* GraphiQL subscriptions support

* 4.3.3-0

* Fix reference

* Fix websocket URL when relative

* 4.3.3-1

* Add @types/ws

* Connection indication, subscription indication, error tracking

* Work around GraphiQL error display issue

* Coloured circle instead of emojis 😞

* Only allow subscriptions over websocket transport

* Enable hooking ws onOperation

* Minimize diff

* Prettier for postgraphiql

* Log error

* Fix headers

* Rename variables, add comments, fix things

* Lint

* Tweak connection indicator icons

package.json

@@ -37,7 +37,7 @@
     "dev": "./scripts/dev",
     "lint": "./scripts/lint",
     "make-assets": "./scripts/make-assets",
-    "prettier": "prettier 'src/**/*.[tj]s'",
+    "prettier": "prettier 'src/**/*.[tj]s' 'postgraphiql/src/**/*.[tj]s'",
     "prettier:fix": "yarn prettier --write",
     "prettier:check": "yarn prettier --list-different",
     "test": "./scripts/test",
@@ -48,6 +48,7 @@
     "@types/jsonwebtoken": "<7.2.1",
     "@types/koa": "^2.0.44",
     "@types/pg": "^7.4.10",
+    "@types/ws": "^6.0.1",
     "body-parser": "^1.15.2",
     "chalk": "^1.1.3",
     "commander": "^2.19.0",
@@ -62,7 +63,9 @@
     "pg-connection-string": "^0.1.3",
     "pg-sql2": "^2.2.1",
     "postgraphile-core": "4.3.1",
-    "tslib": "^1.5.0"
+    "subscriptions-transport-ws": "^0.9.15",
+    "tslib": "^1.5.0",
+    "ws": "^6.1.3"
   },
   "devDependencies": {
     "@babel/core": "7.0.0",

postgraphiql/package.json

@@ -7,8 +7,8 @@
     "graphiql": "npm:@benjie/graphiql@0.12.1-a701b68f61a315280ba3e292275757f37e004ad5",
     "graphiql-explorer": "^0.3.6",
     "graphql": "^14.0.2",
-    "react": "^15.3.2",
-    "react-dom": "^15.3.2",
+    "react": "^16.8.1",
+    "react-dom": "^16.8.1",
     "react-scripts": "^2.1.3"
   },
   "browserslist": [