improve handling when navigating to the root of a non-default space

x-pack/legacy/plugins/spaces/server/lib/request_interceptors/on_post_auth_interceptor.test.ts

@@ -347,6 +347,73 @@ describe('onPostAuthInterceptor', () => {
     );
   });
 
+  it('redirects to the space selector when accessing the root of the default space', async () => {
+    const spaces = [
+      {
+        id: 'default',
+        type: 'space',
+        attributes: {
+          name: 'Default space',
+          _reserved: true,
+        },
+      },
+      {
+        id: 'a-space',
+        type: 'space',
+        attributes: {
+          name: 'a space',
+        },
+      },
+    ];
+
+    const { response, spacesService } = await request('/', spaces);
+
+    expect(response.status).toEqual(302);
+    expect(response.header.location).toEqual(`/spaces/space_selector`);
+
+    expect(spacesService.scopedClient).toHaveBeenCalledWith(
+      expect.objectContaining({
+        headers: expect.objectContaining({
+          authorization: headers.authorization,
+        }),
+      })
+    );
+  }, 30000);
+
+  it('allows the request to continue when accessing the root of a non-default space', async () => {
+    const spaces = [
+      {
+        id: 'default',
+        type: 'space',
+        attributes: {
+          name: 'Default space',
+          _reserved: true,
+        },
+      },
+      {
+        id: 'a-space',
+        type: 'space',
+        attributes: {
+          name: 'a space',
+        },
+      },
+    ];
+
+    const { response, spacesService } = await request('/s/a-space', spaces);
+
+    // OSS handles this redirection for us
+    expect(response.status).toEqual(302);
+    expect(response.header.location).toEqual(`/s/a-space${defaultRoute}`);
+
+    expect(spacesService.scopedClient).toHaveBeenCalledWith(
+      expect.objectContaining({
+        headers: expect.objectContaining({
+          authorization: headers.authorization,
+        }),
+      })
+    );
+  }, 30000);
+
   describe('with a single available space', () => {
     it('it redirects to the defaultRoute within the context of the single Space when navigating to Kibana root', async () => {
       const spaces = [

x-pack/legacy/plugins/spaces/server/lib/request_interceptors/on_post_auth_interceptor.ts

@@ -6,11 +6,12 @@
 import { Logger, CoreSetup } from 'src/core/server';
 import { Space } from '../../../common/model/space';
 import { wrapError } from '../errors';
-import { addSpaceIdToPath, getSpaceIdFromPath } from '../spaces_url_parser';
+import { addSpaceIdToPath } from '../spaces_url_parser';
 import { XPackMainPlugin } from '../../../../xpack_main/xpack_main';
 import { SpacesServiceSetup } from '../../new_platform/spaces_service/spaces_service';
 import { LegacyAPI } from '../../new_platform/plugin';
 import { getSpaceSelectorUrl } from '../get_space_selector_url';
+import { DEFAULT_SPACE_ID } from '../../../common/constants';
 
 export interface OnPostAuthInterceptorDeps {
   getLegacyAPI(): LegacyAPI;
@@ -32,7 +33,11 @@ export function initSpacesOnPostAuthRequestInterceptor({
   http.registerOnPostAuth(async (request, response, toolkit) => {
     const path = request.url.pathname!;
 
-    const isRequestingKibanaRoot = path === '/';
+    const spaceId = spacesService.getSpaceId(request);
+
+    // The root of kibana is also the root of the defaut space,
+    // since the default space does not have a URL Identifier (i.e., `/s/foo`).
+    const isRequestingKibanaRoot = path === '/' && spaceId === DEFAULT_SPACE_ID;
     const isRequestingApplication = path.startsWith('/app');
 
     const spacesClient = await spacesService.scopedClient(request);
@@ -71,11 +76,8 @@ export function initSpacesOnPostAuthRequestInterceptor({
     // This condition should only happen after selecting a space, or when transitioning from one application to another
     // e.g.: Navigating from Dashboard to Timelion
     if (isRequestingApplication) {
-      let spaceId: string = '';
       let space: Space;
       try {
-        spaceId = getSpaceIdFromPath(http.basePath.get(request), serverBasePath);
-
         log.debug(`Verifying access to space "${spaceId}"`);
 
         space = await spacesClient.get(spaceId);