feat: add clear method to clear flag configs (#51)

Author: yuhao900914

packages/experiment-browser/src/experimentClient.ts

@@ -182,6 +182,15 @@ export class ExperimentClient implements Client {
     return { ...this.secondaryVariants(), ...this.sourceVariants() };
   }
 
+  /**
+   * Clear all variants in the cache and storage.
+   *
+   */
+  public clear(): void {
+    this.storage.clear();
+    this.storage.save();
+  }
+
   /**
    * Get a copy of the internal {@link ExperimentUser} object if it is set.
    *

packages/experiment-browser/src/stubClient.ts

@@ -38,5 +38,7 @@ export class StubExperimentClient implements Client {
     return {};
   }
 
+  public clear(): void {}
+
   public exposure(key: string): void {}
 }

packages/experiment-browser/src/types/client.ts

@@ -10,6 +10,7 @@ export interface Client {
   fetch(user?: ExperimentUser): Promise<Client>;
   variant(key: string, fallback?: string | Variant): Variant;
   all(): Variants;
+  clear(): void;
   exposure(key: string): void;
   getUser(): ExperimentUser;
   setUser(user: ExperimentUser): void;

packages/experiment-browser/test/client.test.ts

@@ -162,6 +162,19 @@ test('ExperimentClient.all, initial variants returned', async () => {
   expect(variants).toEqual(initialVariants);
 });
 
+/**
+ * Call clear() to clear all variants in the cache and storage.
+ */
+test('ExperimentClient.clear, clear the variants in storage', async () => {
+  const client = new ExperimentClient(API_KEY, {});
+  await client.fetch(testUser);
+  const variant = client.variant('sdk-ci-test');
+  expect(variant).toEqual({ value: 'on', payload: 'payload' });
+  client.clear();
+  const clearedVariants = client.all();
+  expect(clearedVariants).toEqual({});
+});
+
 /**
  * Setting source to initial variants will prioritize variants in initial
  * variants over those stored in local storage.