feat(hooks): add a hook to the request handler (#770)

package.json

@@ -47,7 +47,7 @@
     "parseurl": "^1.3.1",
     "pg": ">=6.1.0 <8",
     "pg-connection-string": "^0.1.3",
-    "pg-sql2": "2.0.0",
+    "pg-sql2": "2.1.0",
     "postgraphile-core": "4.0.0-beta.7.2",
     "send": "^0.16.1",
     "tslib": "^1.5.0"

src/postgraphile/http/createPostGraphileHttpRequestHandler.js

@@ -308,7 +308,16 @@ export default function createPostGraphileHttpRequestHandler(options) {
    * @param {IncomingMessage} req
    * @param {ServerResponse} res
    */
-  const requestHandler = async (req, res, next) => {
+  const requestHandler = async (incomingReq, res, next) => {
+    // You can use this hook either to modify the incoming request or to tell
+    // PostGraphile not to handle the request further (return null). NOTE: if
+    // you return `null` from this hook then you are also responsible for
+    // calling `next()` (should that be required).
+    const req = pluginHook('postgraphile:http:handler', incomingReq, {options, res, next})
+    if (req == null) {
+      return
+    }
+
     // Add our CORS headers to be good web citizens (there are perf
     // implications though so be careful!)
     //

yarn.lock

@@ -5921,6 +5921,12 @@ [email protected]:
   dependencies:
     debug ">=2 <3"
 
+[email protected]:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/pg-sql2/-/pg-sql2-2.1.0.tgz#f86978278451482099e4f8e8db8b7486ecb67e3f"
+  dependencies:
+    debug ">=2 <3"
+
 pg-types@~1.12.1:
   version "1.12.1"
   resolved "https://registry.yarnpkg.com/pg-types/-/pg-types-1.12.1.tgz#d64087e3903b58ffaad279e7595c52208a14c3d2"