use properly typed errors for obs

x-pack/plugins/global_search/common/errors.test.ts

@@ -0,0 +1,22 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { GlobalSearchFindError } from './errors';
+
+describe('GlobalSearchFindError', () => {
+  describe('#invalidLicense', () => {
+    it('create an error with the correct `type`', () => {
+      const error = GlobalSearchFindError.invalidLicense('foobar');
+      expect(error.message).toBe('foobar');
+      expect(error.type).toBe('invalid-license');
+    });
+
+    it('can be identified via instanceof', () => {
+      const error = GlobalSearchFindError.invalidLicense('foo');
+      expect(error instanceof GlobalSearchFindError).toBe(true);
+    });
+  });
+});

x-pack/plugins/global_search/common/errors.ts

@@ -0,0 +1,27 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+// only one type for now, but already present for future-proof reasons
+export type GlobalSearchFindErrorType = 'invalid-license';
+
+/**
+ * Error thrown from the {@link GlobalSearchPluginStart.find | GlobalSearch find API}'s result observable
+ *
+ * @public
+ */
+export class GlobalSearchFindError extends Error {
+  public static invalidLicense(message: string) {
+    return new GlobalSearchFindError('invalid-license', message);
+  }
+
+  private constructor(public readonly type: GlobalSearchFindErrorType, message: string) {
+    super(message);
+
+    // Set the prototype explicitly, see:
+    // https://github.com/Microsoft/TypeScript/wiki/Breaking-Changes#extending-built-ins-like-error-array-and-map-may-no-longer-work
+    Object.setPrototypeOf(this, GlobalSearchFindError.prototype);
+  }
+}

x-pack/plugins/global_search/public/services/search_service.ts

@@ -9,6 +9,7 @@ import { map, takeUntil } from 'rxjs/operators';
 import { duration } from 'moment';
 import { HttpStart, ApplicationStart } from 'src/core/public';
 import { GlobalSearchProviderResult } from '../../common/types';
+import { GlobalSearchFindError } from '../../common/errors';
 import { takeInArray } from '../../common/operators';
 import { processProviderResult } from '../../common/process_result';
 import { ILicenseChecker } from '../../common/license_checker';
@@ -82,7 +83,9 @@ export class SearchService {
     const licenseState = this.licenseChecker!.getState();
     if (!licenseState.valid) {
       return throwError(
-        `GlobalSearch API is disabled because of invalid license state: ${licenseState.message}`
+        GlobalSearchFindError.invalidLicense(
+          `GlobalSearch API is disabled because of invalid license state: ${licenseState.message}`
+        )
       );
     }
 

x-pack/plugins/global_search/server/routes/find.ts

@@ -7,6 +7,7 @@
 import { reduce, map } from 'rxjs/operators';
 import { schema } from '@kbn/config-schema';
 import { IRouter } from 'src/core/server';
+import { GlobalSearchFindError } from '../../common/errors';
 
 export const registerInternalFindRoute = (router: IRouter) => {
   router.post(
@@ -39,7 +40,10 @@ export const registerInternalFindRoute = (router: IRouter) => {
           },
         });
       } catch (e) {
-        return res.forbidden({ body: e });
+        if (e instanceof GlobalSearchFindError && e.type === 'invalid-license') {
+          return res.forbidden({ body: e.message });
+        }
+        throw e;
       }
     }
   );

x-pack/plugins/global_search/server/services/search_service.ts

@@ -8,6 +8,7 @@ import { Observable, timer, merge, throwError } from 'rxjs';
 import { map, takeUntil } from 'rxjs/operators';
 import { KibanaRequest, CoreStart, IBasePath } from 'src/core/server';
 import { GlobalSearchProviderResult } from '../../common/types';
+import { GlobalSearchFindError } from '../../common/errors';
 import { takeInArray } from '../../common/operators';
 import { ILicenseChecker } from '../../common/license_checker';
 
@@ -84,7 +85,9 @@ export class SearchService {
     const licenseState = this.licenseChecker!.getState();
     if (!licenseState.valid) {
       return throwError(
-        `GlobalSearch API is disabled because of invalid license state: ${licenseState.message}`
+        GlobalSearchFindError.invalidLicense(
+          `GlobalSearch API is disabled because of invalid license state: ${licenseState.message}`
+        )
       );
     }