[LEGACY] Add web support to AsyncStorage

.gitignore

@@ -47,3 +47,5 @@ buck-out/
 
 # Editor config
 .vscode
+.expo
+/web-build

app.json

@@ -0,0 +1,5 @@
+{
+  "expo": {
+    "entryPoint": "./example/index"
+  }
+}

example/index.js

@@ -8,8 +8,13 @@
  * @flow
  */
 
-import {AppRegistry} from 'react-native';
+import {AppRegistry, Platform} from 'react-native';
 import App from './App';
 import {name as appName} from './app.json';
 
 AppRegistry.registerComponent(appName, () => App);
+
+if (Platform.OS === 'web') {
+  const rootTag = document.getElementById('root');
+  AppRegistry.runApplication(appName, {rootTag});
+}

lib/AsyncStorage.web.js

@@ -0,0 +1,158 @@
+/**
+ * Copyright (c) Nicolas Gallagher.
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+import merge from 'deep-assign';
+
+const mergeLocalStorageItem = (key, value) => {
+  const oldValue = window.localStorage.getItem(key);
+  const oldObject = JSON.parse(oldValue);
+  const newObject = JSON.parse(value);
+  const nextValue = JSON.stringify(merge({}, oldObject, newObject));
+  window.localStorage.setItem(key, nextValue);
+};
+
+const createPromise = (getValue, callback): Promise<*> => {
+  return new Promise((resolve, reject) => {
+    try {
+      const value = getValue();
+      if (callback) {
+        callback(null, value);
+      }
+      resolve(value);
+    } catch (err) {
+      if (callback) {
+        callback(err);
+      }
+      reject(err);
+    }
+  });
+};
+
+const createPromiseAll = (promises, callback, processResult): Promise<*> => {
+  return Promise.all(promises).then(
+    result => {
+      const value = processResult ? processResult(result) : null;
+      callback && callback(null, value);
+      return Promise.resolve(value);
+    },
+    errors => {
+      callback && callback(errors);
+      return Promise.reject(errors);
+    }
+  );
+};
+
+export default class AsyncStorage {
+
+  /**
+   * Fetches `key` value.
+   */
+  static getItem(key: string, callback?: Function): Promise<*> {
+    return createPromise(() => {
+      return window.localStorage.getItem(key);
+    }, callback);
+  }
+
+  /**
+   * Sets `value` for `key`.
+   */
+  static setItem(key: string, value: string, callback?: Function): Promise<*> {
+    return createPromise(() => {
+      window.localStorage.setItem(key, value);
+    }, callback);
+  }
+
+  /**
+   * Removes a `key`
+   */
+  static removeItem(key: string, callback?: Function): Promise<*> {
+    return createPromise(() => {
+      return window.localStorage.removeItem(key);
+    }, callback);
+  }
+
+  /**
+   * Merges existing value with input value, assuming they are stringified JSON.
+   */
+  static mergeItem(key: string, value: string, callback?: Function): Promise<*> {
+    return createPromise(() => {
+      mergeLocalStorageItem(key, value);
+    }, callback);
+  }
+
+  /**
+   * Erases *all* AsyncStorage for the domain.
+   */
+  static clear(callback?: Function): Promise<*> {
+    return createPromise(() => {
+      window.localStorage.clear();
+    }, callback);
+  }
+
+  /**
+   * Gets *all* keys known to the app, for all callers, libraries, etc.
+   */
+  static getAllKeys(callback?: Function): Promise<*> {
+    return createPromise(() => {
+      const numberOfKeys = window.localStorage.length;
+      const keys = [];
+      for (let i = 0; i < numberOfKeys; i += 1) {
+        const key = window.localStorage.key(i);
+        keys.push(key);
+      }
+      return keys;
+    }, callback);
+  }
+
+  /**
+   * (stub) Flushes any pending requests using a single batch call to get the data.
+   */
+  static flushGetRequests() {}
+
+  /**
+   * multiGet resolves to an array of key-value pair arrays that matches the
+   * input format of multiSet.
+   *
+   *   multiGet(['k1', 'k2']) -> [['k1', 'val1'], ['k2', 'val2']]
+   */
+  static multiGet(keys: Array<string>, callback?: Function): Promise<*> {
+    const promises = keys.map(key => AsyncStorage.getItem(key));
+    const processResult = result => result.map((value, i) => [keys[i], value]);
+    return createPromiseAll(promises, callback, processResult);
+  }
+
+  /**
+   * Takes an array of key-value array pairs.
+   *   multiSet([['k1', 'val1'], ['k2', 'val2']])
+   */
+  static multiSet(keyValuePairs: Array<Array<string>>, callback?: Function): Promise<*> {
+    const promises = keyValuePairs.map(item => AsyncStorage.setItem(item[0], item[1]));
+    return createPromiseAll(promises, callback);
+  }
+
+  /**
+   * Delete all the keys in the `keys` array.
+   */
+  static multiRemove(keys: Array<string>, callback?: Function): Promise<*> {
+    const promises = keys.map(key => AsyncStorage.removeItem(key));
+    return createPromiseAll(promises, callback);
+  }
+
+  /**
+   * Takes an array of key-value array pairs and merges them with existing
+   * values, assuming they are stringified JSON.
+   *
+   *   multiMerge([['k1', 'val1'], ['k2', 'val2']])
+   */
+  static multiMerge(keyValuePairs: Array<Array<string>>, callback?: Function): Promise<*> {
+    const promises = keyValuePairs.map(item => AsyncStorage.mergeItem(item[0], item[1]));
+    return createPromiseAll(promises, callback);
+  }
+}

package.json

@@ -5,7 +5,9 @@
   "types": "./types/index.d.ts",
   "main": "./lib/index.js",
   "author": "Krzysztof Borowy <[email protected]>",
-  "contributors": [],
+  "contributors": [
+    "Evan Bacon <[email protected]> (https://github.com/evanbacon)"
+  ],
   "homepage": "https://github.com/react-native-community/react-native-async-storage#readme",
   "license": "MIT",
   "keywords": [
@@ -23,6 +25,7 @@
     "start": "node node_modules/react-native/local-cli/cli.js start",
     "start:android": "react-native run-android --root example/",
     "start:ios": "react-native run-ios --project-path example/ios --scheme AsyncStorageExample",
+    "start:web": "expo start:web",
     "start:macos": "node node_modules/react-native-macos/local-cli/cli.js start --use-react-native-macos",
     "build:e2e:ios": "detox build -c ios",
     "build:e2e:android": "detox build -c android",
@@ -38,19 +41,25 @@
     "react": "^16.8",
     "react-native": ">=0.59"
   },
+  "dependencies": {
+    "deep-assign": "^3.0.0"
+  },
   "devDependencies": {
     "@babel/core": "7.4.5",
     "@babel/runtime": "7.4.5",
     "@react-native-community/eslint-config": "0.0.2",
     "babel-jest": "24.8.0",
     "babel-plugin-module-resolver": "3.1.3",
     "detox": "12.6.1",
+    "expo": "36.0.2",
     "eslint": "5.1.0",
     "flow-bin": "0.92.0",
     "jest": "24.8.0",
     "metro-react-native-babel-preset": "0.54.1",
     "react": "16.6.3",
+    "react-dom": "16.6.3",
     "react-native": "0.59.10",
+    "react-native-web": "~0.12.0",
     "react-native-macos": "0.60.0-microsoft.50",
     "react-test-renderer": "16.8.3"
   },