feat: introduce getVisitorDataFromCache and isInCache options

README.md

@@ -179,7 +179,15 @@ const result = await fpjsClient.getVisitorData({ extendedResult: true })
 
 // true if cache was hit
 console.log(result.cacheHit)
+```
+
+You can also use the following API to retrieve responses from cache:
+```js
+// Checks if request matching given options is present in cache
+await fpjsClient.isInCache({ extendedResult: true })
 
+// Returns cached visitor data based on the request options, or undefined if the data is not present in cache
+const cachedResult = await fpjsClient.getVisitorDataFromCache({ extendedResult: true })
 ```
 
 #### Creating a custom cache

__tests__/client.test.ts

@@ -195,6 +195,95 @@ describe(`SPA client`, () => {
     })
   })
 
+  describe('getVisitorDataFromCache', () => {
+    const mockVisitorId = 'abc123'
+    const cachePrefix = 'get_visitor_data_from_cache_test'
+    let agentGetMock: jest.Mock
+
+    beforeEach(() => {
+      agentGetMock = jest.fn(async () => {
+        return {
+          visitorId: mockVisitorId,
+        } as FingerprintJS.GetResult
+      })
+      // @ts-ignore
+      jest.spyOn(FingerprintJS, 'load').mockImplementation(async () => {
+        return {
+          get: agentGetMock,
+        }
+      })
+    })
+
+    afterEach(() => {
+      localStorage.clear()
+    })
+
+    it('should return response if it is cached, and undefined if it is not', async () => {
+      const client = new FpjsClient({
+        loadOptions: getDefaultLoadOptions(),
+        cacheLocation: CacheLocation.LocalStorage,
+        cachePrefix,
+      })
+      await client.init()
+
+      const response = await client.getVisitorData()
+
+      const cachedResponse = await client.getVisitorDataFromCache()
+
+      expect(cachedResponse).toEqual({
+        ...response,
+        cacheHit: true,
+      })
+
+      expect(agentGetMock).toHaveBeenCalledTimes(1)
+
+      const notCachedResponse = await client.getVisitorDataFromCache({ extendedResult: true })
+
+      expect(notCachedResponse).toBeUndefined()
+    })
+  })
+
+  describe('isInCache', () => {
+    const mockVisitorId = 'abc123'
+    const cachePrefix = 'is_in_cache_test'
+    let agentGetMock: jest.Mock
+
+    beforeEach(() => {
+      agentGetMock = jest.fn(async () => {
+        return {
+          visitorId: mockVisitorId,
+        } as FingerprintJS.GetResult
+      })
+      // @ts-ignore
+      jest.spyOn(FingerprintJS, 'load').mockImplementation(async () => {
+        return {
+          get: agentGetMock,
+        }
+      })
+    })
+
+    afterEach(() => {
+      localStorage.clear()
+    })
+
+    it('should return true if response is cached', async () => {
+      const client = new FpjsClient({
+        loadOptions: getDefaultLoadOptions(),
+        cacheLocation: CacheLocation.LocalStorage,
+        cachePrefix,
+      })
+      await client.init()
+
+      await client.getVisitorData()
+      await client.getVisitorData()
+
+      expect(agentGetMock).toHaveBeenCalledTimes(1)
+      await expect(client.isInCache()).resolves.toEqual(true)
+      await expect(client.isInCache({ extendedResult: true })).resolves.toEqual(false)
+      await expect(client.isInCache({ tag: 'tag' })).resolves.toEqual(false)
+    })
+  })
+
   describe('getVisitorData', () => {
     const mockVisitorId = 'abc123'
     const cachePrefix = 'cache_test'

src/client.ts

@@ -175,6 +175,24 @@ export class FpjsClient {
     return (await this.inFlightRequests.get(key)) as FpjsSpaResponse<VisitorData<TExtended>>
   }
 
+  /**
+   * Returns cached visitor data based on the request options, or undefined if the data is not present in cache
+   * */
+  public async getVisitorDataFromCache<TExtended extends boolean>(
+    options: GetOptions<TExtended> = {}
+  ): Promise<FpjsSpaResponse<VisitorData<TExtended>> | undefined> {
+    const cacheKey = FpjsClient.makeCacheKey(options)
+    const cacheResult = await this.cacheManager.get(cacheKey)
+    return cacheResult ? { ...cacheResult, cacheHit: true } : undefined
+  }
+
+  /**
+   * Checks if request matching given options is present in cache
+   * */
+  public async isInCache(options: GetOptions<boolean> = {}) {
+    return Boolean(await this.getVisitorDataFromCache(options))
+  }
+
   /**
    * Clears visitor data from cache regardless of the cache implementation
    */