Add in memory dev data store as a configuration option. This allows u…

configuration.js

@@ -21,7 +21,8 @@ module.exports = (function() {
       privateAttributeNames: [],
       userKeysCapacity: 1000,
       userKeysFlushInterval: 300,
-      featureStore: InMemoryFeatureStore()
+      featureStore: InMemoryFeatureStore(),
+      inMemoryDevFlags: false,
     };
   };
 
@@ -132,7 +133,7 @@ module.exports = (function() {
 
   function validate(options) {
     let config = Object.assign({}, options || {});
-    
+
     config.userAgent = 'NodeJSClient/' + package_json.version;
     config.logger = (config.logger ||
       new winston.Logger({
@@ -146,7 +147,7 @@ module.exports = (function() {
         ]
       })
     );
-    
+
     checkDeprecatedOptions(config);
 
     const defaultConfig = defaults();

in_memory_data_source.js

@@ -0,0 +1,45 @@
+/*
+  DevDataSource provides a way to pass features in to dev without connecting to LaunchDarkly's live service.
+  This would typically be used in a local development environment.
+*/
+
+function InMemoryDataSource(features) {
+  if (!features) {
+    return;
+  }
+
+  const flags = {};
+  Object.keys(features).forEach(key => {
+    flags[key] = {
+      key,
+      on: features[key],
+    };
+  });
+  const ld_features = {
+    flags,
+    segments: {},
+  };
+
+  return (config) => {
+    let inited = false;
+    const featureStore = config.featureStore;
+
+    const dev_ds = {
+      start: fn => {
+        featureStore.init(ld_features, () => {
+          inited = true;
+        });
+        const cb = fn || (() => {});
+        cb();
+      },
+      stop: () => {},
+      initialized: () => inited,
+      close: () => {
+        dev_ds.stop();
+      },
+    };
+    return dev_ds;
+  };
+}
+
+module.exports = InMemoryDataSource;

index.js

@@ -8,6 +8,7 @@ const EventProcessor = require('./event_processor');
 const PollingProcessor = require('./polling');
 const StreamingProcessor = require('./streaming');
 const FlagsStateBuilder = require('./flags_state');
+const InMemoryDataSource = require('./in_memory_data_source');
 const configuration = require('./configuration');
 const evaluate = require('./evaluate_flag');
 const messages = require('./messages');
@@ -62,7 +63,7 @@ const newClient = function(sdkKey, originalConfig) {
     eventFactoryWithReasons;
 
   const config = configuration.validate(originalConfig);
-  
+
   // Initialize global tunnel if proxy options are set
   if (config.proxyHost && config.proxyPort ) {
     config.proxyAgent = createProxyAgent(config);
@@ -90,11 +91,15 @@ const newClient = function(sdkKey, originalConfig) {
   }
 
   const createDefaultUpdateProcessor = config => {
+    if (config.inMemoryDevFlags) {
+      config.logger.info('Creating in-memory flags for offline usage');
+      return InMemoryDataSource(config.inMemoryDevFlags);
+    }
     if (config.useLdd || config.offline) {
       return NullUpdateProcessor();
     } else {
       requestor = Requestor(sdkKey, config);
-  
+
       if (config.stream) {
         config.logger.info('Initializing stream processor to receive feature flag updates');
         return StreamingProcessor(sdkKey, config, requestor);

test/event_processor-test.js

@@ -16,6 +16,18 @@ describe('EventProcessor', () => {
       warn: jest.fn()
     }
   };
+  const developmentConfig = {
+    eventsUri: eventsUri,
+    capacity: 100,
+    flushInterval: 30,
+    userKeysCapacity: 1000,
+    userKeysFlushInterval: 300,
+    inMemoryDevFlags: { 'development-feature': true },
+    logger: {
+      debug: jest.fn(),
+      warn: jest.fn()
+    }
+  };
   const user = { key: 'userKey', name: 'Red' };
   const filteredUser = { key: 'userKey', privateAttrs: [ 'name' ] };
   const numericUser = { key: 1, secondary: 2, ip: 3, country: 4, email: 5, firstName: 6, lastName: 7,
@@ -212,6 +224,19 @@ describe('EventProcessor', () => {
     });
   }));
 
+  it('processes offline events when defined', eventsServerTest(async s => {
+    const config = Object.assign({}, developmentConfig, { allAttributesPrivate: true });
+    await withEventProcessor(config, s, async ep => {
+      const e = developmentConfig.inMemoryDevFlags['development-feature']
+      ep.sendEvent(e);
+      await ep.flush();
+
+      const output = await getJsonRequest(s);
+      expect(output.length).toEqual(1);
+      expect(output[0]).toEqual(e)
+    });
+  }));
+
   it('stringifies user attributes in feature event', eventsServerTest(async s => {
     const config = Object.assign({}, defaultConfig, { inlineUsersInEvents: true });
     await withEventProcessor(config, s, async ep => {
@@ -297,7 +322,7 @@ describe('EventProcessor', () => {
       const serverTime = new Date().getTime() - 20000;
       s.forMethodAndPath('post', '/bulk', TestHttpHandlers.respond(200, headersWithDate(serverTime)));
 
-      // Send and flush an event we don't care about, just to set the last server time        
+      // Send and flush an event we don't care about, just to set the last server time
       ep.sendEvent({ kind: 'identify', user: { key: 'otherUser' } });
       await ep.flush();
       await s.nextRequest();
@@ -536,7 +561,7 @@ describe('EventProcessor', () => {
   it('swallows errors from failed background flush', eventsServerTest(async s => {
     // This test verifies that when a background flush fails, we don't emit an unhandled
     // promise rejection. Jest will fail the test if we do that.
-    
+
     const config = Object.assign({}, defaultConfig, { flushInterval: 0.25 });
     await withEventProcessor(config, s, async ep => {
       s.forMethodAndPath('post', '/bulk', TestHttpHandlers.respond(500));