chore: small refactor and some new config.d.ts

Signed-off-by: blam <ben@blam.sh>

packages/backend-defaults/config.d.ts

@@ -22,6 +22,24 @@ export interface Config {
   };
 
   backend?: {
+    /**
+     * Backend configuration for when request authentication is enabled
+     *
+     * @deprecated this will be removed when the backwards compatibility is no longer needed with backend-common
+     */
+    auth?: {
+      /** Keys shared by all backends for signing and validating backend tokens. */
+      keys?: {
+        /**
+         * Secret for generating tokens. Should be a base64 string, recommended
+         * length is 24 bytes.
+         *
+         * @visibility secret
+         */
+        secret: string;
+      }[];
+    };
+
     /**
      * The full base URL of the backend, as seen from the browser's point of
      * view as it makes calls to the backend.

packages/config-loader/src/schema/collect.ts

@@ -153,18 +153,17 @@ export async function collectConfigSchemas(
   ]);
 
   const tsSchemas = await compileTsSchemas(tsSchemaPaths);
+  const allSchemas = schemas.concat(tsSchemas);
 
-  return schemas
-    .concat(tsSchemas)
-    .filter(
-      ({ packageName }, _, original) =>
-        !(
-          packageName === '@backstage/backend-common' &&
-          original.some(
-            ({ packageName: p }) => p === '@backstage/backend-defaults',
-          )
-        ),
-    );
+  const isMissingBackendDefaults = !allSchemas.some(
+    ({ packageName }) => packageName === '@backstage/backend-defaults',
+  );
+
+  // Filter out the backend-common schema unless the backend-defaults schema is missing
+  return allSchemas.filter(
+    ({ packageName }) =>
+      packageName !== '@backstage/backend-common' || isMissingBackendDefaults,
+  );
 }
 
 // This handles the support of TypeScript .d.ts config schema declarations.