backend-defaults: pretty-print JSON responses during development

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/slow-walls-report.md

@@ -0,0 +1,13 @@
+---
+'@backstage/backend-defaults': patch
+---
+
+The default root HTTP service implementation will now pretty-print JSON responses in development.
+
+If you are overriding the `rootHttpRouterServiceFactory` with a `configure` function that doesn't call `applyDefaults`, you can introduce this functionality by adding the following snippet inside `configure`:
+
+```ts
+if (process.env.NODE_ENV === 'development') {
+  app.set('json spaces', 2);
+}
+```

docs/backend-system/core-services/root-http-router.md

@@ -59,7 +59,7 @@ const backend = createBackend();
 
 backend.add(
   rootHttpRouterServiceFactory({
-    configure: ({ app, middleware, routes, config, logger, lifecycle }) => {
+    configure: ({ app, middleware, routes, config, logger, healthRouter }) => {
       // Refer to https://expressjs.com/en/guide/writing-middleware.html on how to write express middleware
       const customMiddleware = {
         logging(): RequestHandler {
@@ -88,11 +88,18 @@ backend.add(
         },
       };
 
+      // The default implementation pretty-prints JSON responses in development
+      if (process.env.NODE_ENV === 'development') {
+        app.set('json spaces', 2);
+      }
+
       // the built in middleware is provided through an option in the configure function
       app.use(middleware.helmet());
       app.use(middleware.cors());
       app.use(middleware.compression());
 
+      app.use(healthRouter);
+
       // you can add you your own middleware in here
       app.use(customMiddleware.logging());
 

packages/backend-defaults/src/entrypoints/rootHttpRouter/rootHttpRouterServiceFactory.ts

@@ -106,6 +106,9 @@ const rootHttpRouterServiceFactoryWithOptions = (
         lifecycle,
         healthRouter,
         applyDefaults() {
+          if (process.env.NODE_ENV === 'development') {
+            app.set('json spaces', 2);
+          }
           app.use(middleware.helmet());
           app.use(middleware.cors());
           app.use(middleware.compression());