[KIbana Utils] createGetterSetter should work with optional plugins (#114128)

src/plugins/kibana_utils/common/create_getter_setter.test.ts

@@ -0,0 +1,38 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { createGetterSetter } from './create_getter_setter';
+
+describe('createGetterSetter', () => {
+  test('should be able to create getter/setter', () => {
+    const [getString, setString] = createGetterSetter<{}>('string');
+
+    expect(getString).toBeInstanceOf(Function);
+    expect(setString).toBeInstanceOf(Function);
+  });
+
+  test('getter should return the set value', () => {
+    const [getString, setString] = createGetterSetter<{}>('string');
+
+    setString('test');
+    expect(getString()).toBe('test');
+  });
+
+  test('getter should throw an exception', () => {
+    const [getString] = createGetterSetter<{}>('string');
+
+    expect(() => getString()).toThrowErrorMatchingInlineSnapshot(`"string was not set."`);
+  });
+
+  test('getter should not throw an exception (isValueRequired is false)', () => {
+    const [getString] = createGetterSetter<{}>('string', false);
+    const value = getString();
+
+    expect(value).toBeUndefined();
+  });
+});

src/plugins/kibana_utils/common/create_getter_setter.ts

@@ -9,11 +9,16 @@
 export type Get<T> = () => T;
 export type Set<T> = (value: T) => void;
 
-export const createGetterSetter = <T extends object>(name: string): [Get<T>, Set<T>] => {
+export const createGetterSetter = <T extends object>(
+  name: string,
+  isValueRequired: boolean = true
+): [Get<T>, Set<T>] => {
   let value: T;
 
   const get: Get<T> = () => {
-    if (!value) throw new Error(`${name} was not set.`);
+    if (!value && isValueRequired) {
+      throw new Error(`${name} was not set.`);
+    }
     return value;
   };