Support for configurable response headers in publisher

packages/npm/@amazeelabs/publisher/publisher.config.ts

@@ -45,4 +45,8 @@ export default defineConfig({
     },
   },
   databaseUrl: './test/database.sqlite',
+  responseHeaders: new Map()
+    .set('X-Frame-Options', 'deny')
+    .set('X-Content-Type-Options', 'nosniff')
+    .set('Content-Security-Policy', "frame-ancestors 'none'"),
 });

packages/npm/@amazeelabs/publisher/src/core/tools/config.ts

@@ -125,6 +125,13 @@ export type PublisherConfig = {
     credentials: boolean;
     origin: Array<string>;
   };
+  /**
+   * A Map of response headers that should be added to every route.
+   *
+   * Example: (new Map()).set('X-Frame-Options', 'deny')
+   * The above would set the "X-Frame-Options" response header to "deny".
+   */
+  responseHeaders?: Map<string, string>;
   /**
    * Proxy settings.
    *

packages/npm/@amazeelabs/publisher/src/server.ts

@@ -66,6 +66,20 @@ const runServer = async (): Promise<HttpTerminator> => {
     next();
   });
 
+  // Add any configured response headers which should apply on every route.
+  app.use((req, res, next) => {
+    // The spread operator applied on a Map generates a 2D key-value array. So
+    // if we have a Map with two items: key1 => value1, key2 => value2, then
+    // the spread operator applied on the Map would return
+    // [["key1", "value1"], ["key2", "value2"]].
+    [...(getConfig().responseHeaders || new Map<string, string>())].map(
+      (responseHeader) => {
+        res.set(responseHeader[0], responseHeader[1]);
+      },
+    );
+    next();
+  });
+
   core.state.applicationState$.subscribe((state) => {
     app.locals.isReady = state === ApplicationState.Ready;
     stateNotify(state);