add ServiceConfigDescriptor type

src/core/server/internal_types.ts

@@ -17,7 +17,10 @@
  * under the License.
  */
 
+import { Type } from '@kbn/config-schema';
+
 import { CapabilitiesSetup, CapabilitiesStart } from './capabilities';
+import { ConfigDeprecationProvider } from './config';
 import { ContextSetup } from './context';
 import { InternalElasticsearchServiceSetup } from './elasticsearch';
 import { InternalHttpServiceSetup } from './http';
@@ -47,3 +50,18 @@ export interface InternalCoreStart {
   savedObjects: InternalSavedObjectsServiceStart;
   uiSettings: InternalUiSettingsServiceStart;
 }
+
+/**
+ * @internal
+ */
+export interface ServiceConfigDescriptor<T = any> {
+  path: string;
+  /**
+   * Schema to use to validate the configuration.
+   */
+  schema: Type<T>;
+  /**
+   * Provider for the {@link ConfigDeprecation} to apply to the plugin configuration.
+   */
+  deprecations?: ConfigDeprecationProvider;
+}

src/core/server/server.ts

@@ -257,7 +257,10 @@ export class Server {
     ];
 
     this.configService.addDeprecationProvider(rootConfigPath, coreDeprecationProvider);
-    this.configService.addDeprecationProvider(uiSettingsConfig.path, uiSettingsConfig.deprecations);
+    this.configService.addDeprecationProvider(
+      uiSettingsConfig.path,
+      uiSettingsConfig.deprecations!
+    );
 
     for (const [path, schema] of schemas) {
       await this.configService.setSchema(path, schema);

src/core/server/ui_settings/ui_settings_config.ts

@@ -19,31 +19,34 @@
 
 import { schema, TypeOf } from '@kbn/config-schema';
 import { ConfigDeprecationProvider } from 'src/core/server';
+import { ServiceConfigDescriptor } from '../internal_types';
 
 const deprecations: ConfigDeprecationProvider = ({ unused, renameFromRoot }) => [
   unused('enabled'),
   renameFromRoot('server.defaultRoute', 'uiSettings.overrides.defaultRoute'),
 ];
 
-export type UiSettingsConfigType = TypeOf<typeof config.schema>;
+const configSchema = schema.object({
+  overrides: schema.object(
+    {
+      defaultRoute: schema.maybe(
+        schema.string({
+          validate(value) {
+            if (!value.startsWith('/')) {
+              return 'must start with a slash';
+            }
+          },
+        })
+      ),
+    },
+    { allowUnknowns: true }
+  ),
+});
 
-export const config = {
+export type UiSettingsConfigType = TypeOf<typeof configSchema>;
+
+export const config: ServiceConfigDescriptor<UiSettingsConfigType> = {
   path: 'uiSettings',
-  schema: schema.object({
-    overrides: schema.object(
-      {
-        defaultRoute: schema.maybe(
-          schema.string({
-            validate(value) {
-              if (!value.startsWith('/')) {
-                return 'must start with a slash';
-              }
-            },
-          })
-        ),
-      },
-      { allowUnknowns: true }
-    ),
-  }),
+  schema: configSchema,
   deprecations,
 };