feat(parameters): add clearCaches function (#1382)

Author: dreamorosi

Diff for: packages/parameters/src/BaseProvider.ts

@@ -220,9 +220,21 @@ const transformValues = (value: Record<string, string | undefined>, transform: T
   return transformedValues;
 };
 
+/**
+ * Utility function to clear all the caches of the default providers.
+ * 
+ * This is useful when you want to clear the cache of all the providers at once, for example during testing.
+ */
+const clearCaches = (): void => {
+  for (const provider of Object.values(DEFAULT_PROVIDERS)) {
+    provider.clearCache();
+  }
+};
+
 export {
   BaseProvider,
   ExpirableValue,
   transformValue,
   DEFAULT_PROVIDERS,
+  clearCaches,
 };

Diff for: packages/parameters/tests/unit/BaseProvider.test.ts

@@ -7,7 +7,9 @@ import {
   BaseProvider,
   ExpirableValue,
   GetParameterError,
-  TransformParameterError
+  TransformParameterError,
+  clearCaches,
+  DEFAULT_PROVIDERS,
 } from '../../src';
 import { toBase64 } from '@aws-sdk/util-base64-node';
 
@@ -480,4 +482,39 @@ describe('Class: BaseProvider', () => {
 
   });
 
+});
+
+describe('Function: clearCaches', () => {
+
+  class TestProvider extends BaseProvider {
+
+    public _get(_name: string): Promise<string> {
+      throw Error('Not implemented.');
+    }
+    
+    public _getMultiple(_path: string): Promise<Record<string, string | undefined>> {
+      throw Error('Not implemented.');
+    }
+
+  }
+
+  test('when called, it clears all the caches', () => {
+
+    // Prepare
+    const provider1 = new TestProvider();
+    const provider2 = new TestProvider();
+    const provider1Spy = jest.spyOn(provider1, 'clearCache');
+    const provider2Spy = jest.spyOn(provider2, 'clearCache');
+    DEFAULT_PROVIDERS.ssm = provider1;
+    DEFAULT_PROVIDERS.secretsManager = provider2;
+
+    // Act
+    clearCaches();
+
+    // Assess
+    expect(provider1Spy).toBeCalledTimes(1);
+    expect(provider2Spy).toBeCalledTimes(1);
+
+  });
+
 });