optimizely · mjc1283 · Mar 20, 2020 · Mar 12, 2020 · Mar 12, 2020 · Mar 18, 2020
diff --git a/.travis.yml b/.travis.yml
@@ -82,10 +82,11 @@ jobs:
     - &packagetest
       stage: 'Test sub packages'
       node_js: '12'
-      before_install: cd packages/datafile-manager
+      before_install: cd packages/utils
     - <<: *packagetest
       before_install: cd packages/event-processor
     - <<: *packagetest
       before_install: cd packages/logging
     - <<: *packagetest
-      before_install: cd packages/utils
+      before_script: npm install "@react-native-community/async-storage"
+      before_install: cd packages/datafile-manager
diff --git a/packages/datafile-manager/__mocks__/@react-native-community/async-storage.ts b/packages/datafile-manager/__mocks__/@react-native-community/async-storage.ts
@@ -0,0 +1,37 @@
+/**
+ * Copyright 2020, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export default class AsyncStorage {
+  static getItem(key: string, callback?: (error?: Error, result?: string) => void): Promise<string | null> {
+    return new Promise((resolve, reject) => {
+      switch (key) {
+        case 'keyThatExists':
+          resolve('{ "name": "Awesome Object" }')
+          break
+        case 'keyThatDoesNotExist':
+          resolve(null)
+          break
+        case 'keyWithInvalidJsonObject':
+          resolve('bad json }')
+          break
+      }
+    })
+  }
+
+  static setItem(key: string, value: string, callback?: (error?: Error) => void): Promise<void> {
+    return Promise.resolve()
+  }
+}
diff --git a/packages/datafile-manager/__test__/reactNativeAsyncStorageCache.spec.ts b/packages/datafile-manager/__test__/reactNativeAsyncStorageCache.spec.ts
@@ -0,0 +1,65 @@
+/**
+ * Copyright 2020, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import ReactNativeAsyncStorageCache from '../src/reactNativeAsyncStorageCache'
+
+describe('reactNativeAsyncStorageCache', () => {
+  let cacheInstance: ReactNativeAsyncStorageCache
+
+  beforeEach(() => {
+    cacheInstance = new ReactNativeAsyncStorageCache()
+  })
+
+  describe('get', function() {
+    it('should return correct object when item is found in cache', function() {
+      return cacheInstance.get('keyThatExists')
+        .then(v => expect(v).toEqual({ name: "Awesome Object" }))
+    })
+
+    it('should return null if item is not found in cache', function() {
+      return cacheInstance.get('keyThatDoesNotExist').then(v => expect(v).toBeNull())
+    })
+
+    it('should reject promise error if string has an incorrect JSON format', function() {
+      return cacheInstance.get('keyWithInvalidJsonObject')
+        .catch(() => 'exception caught').then(v => { expect(v).toEqual('exception caught') })
+    })
+  })
+
+  describe('set', function() { 
+    it('should resolve promise if item was successfully set in the cache', function() {
+      const testObj = { name: "Awesome Object" }
+      return cacheInstance.set('testKey', testObj)
+    })
+
+    it('should reject promise if item was not set in the cache because of json stringifying error', function() {
+      const testObj: any = { name: "Awesome Object" }
+      testObj.myOwnReference = testObj
+      return cacheInstance.set('testKey', testObj)
+        .catch(() => 'exception caught').then(v => expect(v).toEqual('exception caught'))
+    })
+  })
+
+  describe('contains', function() {
+    it('should return true if object with key exists', function() {
+      return cacheInstance.contains('keyThatExists').then(v => expect(v).toBeTruthy())
+    })
+
+    it('should return false if object with key does not exist', function() {
+      return cacheInstance.contains('keyThatDoesNotExist').then(v => expect(v).toBeFalsy())
+    })
+  })
+})
diff --git a/packages/datafile-manager/package.json b/packages/datafile-manager/package.json
@@ -38,6 +38,9 @@
     "@optimizely/js-sdk-logging": "^0.1.0",
     "@optimizely/js-sdk-utils": "^0.1.0"
   },
+  "peerDependencies": {
+    "@react-native-community/async-storage": "^1.2.0"
+  },
   "scripts": {
     "test": "jest",
     "tsc": "rm -rf lib && tsc",

diff --git a/packages/datafile-manager/src/persistentKeyValueCache.ts b/packages/datafile-manager/src/persistentKeyValueCache.ts
@@ -0,0 +1,61 @@
+/**
+ * Copyright 2020, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * An Interface to implement a persistent key value cache which supports strings as keys
+ * and JSON Object as value.
+ */
+export default interface PersistentKeyValueCache {
+
+  /**
+   * Returns value stored against a key or null if not found.
+   * @param key 
+   * @returns 
+   * Resolves promise with
+   * 1. Object if value found was stored as a JSON Object.
+   * 2. null if the key does not exist in the cache.
+   * Rejects the promise in case of an error
+   */
+  get(key: string): Promise<any | null>
+
+  /**
+   * Stores Object in the persistent cache against a key
+   * @param key 
+   * @param val 
+   * @returns 
+   * Resolves promise without a value if successful
+   * Rejects the promise in case of an error
+   */
+  set(key: string, val: any): Promise<void>
+
+  /**
+   * Checks if a key exists in the cache
+   * @param key
+   * Resolves promise with 
+   * 1. true if the key exists
+   * 2. false if the key does not exist
+   * Rejects the promise in case of an error
+   */
+  contains(key: string): Promise<Boolean>
+
+  /**
+   * Removes the key value pair from cache.
+   * @param key
+   * Resolves promise without a value if successful
+   * Rejects the promise in case of an error
+   */
+  remove(key: string): Promise<void>
+}
diff --git a/packages/datafile-manager/src/reactNativeAsyncStorageCache.ts b/packages/datafile-manager/src/reactNativeAsyncStorageCache.ts
@@ -0,0 +1,56 @@
+/**
+ * Copyright 2020, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { getLogger } from '@optimizely/js-sdk-logging'
+import AsyncStorage from '@react-native-community/async-storage'
+
+import PersistentKeyValueCache from './persistentKeyValueCache'
+
+const logger = getLogger('DatafileManager')
+
+export default class ReactNativeAsyncStorageCache implements PersistentKeyValueCache {
+  get(key: string): Promise<any | null> {
+    return AsyncStorage.getItem(key)
+      .then((val: string | null) => {
+        if (!val) {
+          return null
+        }
+        try {
+          return JSON.parse(val);
+        } catch (ex) {
+          logger.error('Error Parsing Object from cache - %s', ex)
+          throw ex
+        }  
+      })
+  }
+
+  set(key: string, val: any): Promise<void> {    
+    try {
+      return AsyncStorage.setItem(key, JSON.stringify(val))
+    } catch (ex) {
+      logger.error('Error stringifying Object to Json - %s', ex)
+      return Promise.reject(ex)
+    }
+  }
+
+  contains(key: string): Promise<Boolean> {
+    return AsyncStorage.getItem(key).then((val: string | null) => (val !== null))
+  }
+
+  remove(key: string): Promise<void> {
+    return AsyncStorage.removeItem(key)
+  }
+}