feat: add functionality to register plugins via http

Also:

- Add functionality for serving the responses from plugins
- Add tests for related methods and routes

Closes #2, #37

src/app.ts

@@ -25,15 +25,17 @@ import * as cors from 'cors';
 import * as express from 'express';
 import * as morgan from 'morgan';
 import {join} from 'path';
-import {configFile, isTestEnvironment, mailer, validator} from './common';
+import {configFile, isTestEnvironment, mailer, plugins, validator} from './common';
 import {MailQueue} from './notification/mail-queue';
 import {bulkAddRouter} from './routes/bulk-add-route';
 import {bulkDoneRouter} from './routes/bulk-done-route';
 import {bulkRouter} from './routes/bulk-route';
 import {indexRouter} from './routes/index-route';
 import {multiSearchRouter} from './routes/multi-search-route';
+import {pluginRegisterRouter} from './routes/plugin-register-route';
 import {searchRouter} from './routes/search-route';
 import {thingUpdateRouter} from './routes/thing-update-route';
+import {virtualPluginRoute} from './routes/virtual-plugin-route';
 import {BulkStorage} from './storage/bulk-storage';
 import {DatabaseConstructor} from './storage/database';
 import {Elasticsearch} from './storage/elasticsearch/elasticsearch';
@@ -193,16 +195,32 @@ export async function configureApp() {
     bulkRouter,
     indexRouter,
     multiSearchRouter,
+    pluginRegisterRouter,
     searchRouter,
     thingUpdateRouter,
   );
 
+  // for plugins, as Express doesn't really want you to unregister routes (and doesn't offer any method to do so at all)
+  app.all('*', async (req, res, next) => {
+    // if the route exists then call virtual route on the plugin that registered that route
+    if (plugins.has(req.originalUrl)) {
+      try {
+        res.json(await virtualPluginRoute(req, plugins.get(req.originalUrl)!));
+      } catch (e) {
+        // in case of error send an error response
+        res.status(e.statusCode);
+        res.json(e);
+      }
+    } else {
+      // pass to the next matching route (which is 404)
+      next();
+    }
+  });
+
   // add a route for a missing resource (404)
   app.use((_req, res) => {
     const errorResponse = new SCNotFoundErrorResponse(isTestEnvironment);
     res.status(errorResponse.statusCode);
     res.json(errorResponse);
   });
-
-  // TODO: implement a route to register plugins
 }