Sticky sessions; handle getAssignment called before initialization (#4)

* Sticky sessions; handle getAssignment called before initialization

* log assignment when returning session override

* pass logger to getInstance method

* remove usage with react section

* compare to true string

* pass logger to init

* logger event queue

* update docs

* null check

* use allowList when enabled is false

* simplify

* fix test

* compare to true string

Author: ploomiz

README.md

@@ -8,52 +8,3 @@ This SDK is for client-side JS applications that run in a web browser. For serve
 ## Getting Started
 
 Refer to our [SDK documentation](https://docs.geteppo.com/feature-flagging/randomization-sdk) for how to install and use the SDK.
-
-## Usage with React
-
-For usage in React applications, we recommend creating a [Context](https://reactjs.org/docs/context.html) provider to intialize the SDK and store the initialization status.
-
-```tsx
-import { useEffect, useState, createContext } from 'react';
-import * as EppoSdk from '@eppo/js-client-sdk';
-
-const EppoContext = createContext({ isInitialized: false });
-
-function EppoProvider({ children }): JSX.Element {
-  const [isInitialized, setIsInitialized] = useState(false);
-
-  useEffect(() => {
-    EppoSdk.init({ apiKey: '<API-KEY>' })
-      .then(() => setIsInitialized(true));
-  }, []);
-
-  return (
-     <EppoContext.Provider value={{ isInitialized }}>
-        {children}
-     </EppoContext.Provider>
-  );
-}
-```
-
-Use the context provider at the root of your component tree to wrap the rest of your application:
-
-```tsx
-<EppoProvider>
-   <MyApp />
-</EppoProvider>
-```
-
-React components in your application should consume the context to check that the SDK has been initialized before assigning a variation. (Alternatively, you could have the `EppoProvider` wait to render its children until the SDK is initialized.)
-
-```tsx
-import { useContext } from 'react';
-import * as EppoSdk from '@eppo/js-client-sdk';
-
-const { isInitialized } = useContext(EppoContext);
-if (isInitialized) {
-  const assignedVariation = EppoSdk.getInstance().getAssignment(subjectKey, experimentKey);
-  ...
-}
-```
-
-

docs/js-client-sdk.iclientconfig.assignmentlogger.md

@@ -9,5 +9,5 @@ Pass a logging implementation to send variation assignments to your data warehou
 <b>Signature:</b>
 
 ```typescript
-assignmentLogger?: IAssignmentLogger;
+assignmentLogger: IAssignmentLogger;
 ```

docs/js-client-sdk.iclientconfig.md

@@ -17,6 +17,6 @@ export interface IClientConfig
 |  Property | Type | Description |
 |  --- | --- | --- |
 |  [apiKey](./js-client-sdk.iclientconfig.apikey.md) | string | Eppo API key |
-|  [assignmentLogger?](./js-client-sdk.iclientconfig.assignmentlogger.md) | [IAssignmentLogger](./js-client-sdk.iassignmentlogger.md) | <i>(Optional)</i> Pass a logging implementation to send variation assignments to your data warehouse. |
+|  [assignmentLogger](./js-client-sdk.iclientconfig.assignmentlogger.md) | [IAssignmentLogger](./js-client-sdk.iassignmentlogger.md) | Pass a logging implementation to send variation assignments to your data warehouse. |
 |  [baseUrl?](./js-client-sdk.iclientconfig.baseurl.md) | string | <i>(Optional)</i> Base URL of the Eppo API. Clients should use the default setting in most cases. |
 

docs/js-client-sdk.init.md

@@ -4,7 +4,7 @@
 
 ## init() function
 
-Initializes the Eppo client with configuration parameters. This method should be called once on application startup. After invocation of this method, the SDK will poll Eppo's API at regular intervals to retrieve assignment configurations.
+Initializes the Eppo client with configuration parameters. This method should be called once on application startup.
 
 <b>Signature:</b>
 

docs/js-client-sdk.md

@@ -9,7 +9,7 @@
 |  Function | Description |
 |  --- | --- |
 |  [getInstance()](./js-client-sdk.getinstance.md) | Used to access a singleton SDK client instance. Use the method after calling init() to initialize the client. |
-|  [init(config)](./js-client-sdk.init.md) | Initializes the Eppo client with configuration parameters. This method should be called once on application startup. After invocation of this method, the SDK will poll Eppo's API at regular intervals to retrieve assignment configurations. |
+|  [init(config)](./js-client-sdk.init.md) | Initializes the Eppo client with configuration parameters. This method should be called once on application startup. |
 
 ## Interfaces
 

js-client-sdk.api.md

@@ -25,7 +25,7 @@ export interface IAssignmentLogger {
 // @public
 export interface IClientConfig {
     apiKey: string;
-    assignmentLogger?: IAssignmentLogger;
+    assignmentLogger: IAssignmentLogger;
     baseUrl?: string;
 }
 

src/constants.ts

@@ -1,2 +1,6 @@
 export const REQUEST_TIMEOUT_MILLIS = 5000;
 export const BASE_URL = 'https://eppo.cloud/api';
+export const SESSION_ASSIGNMENT_CONFIG_LOADED = 'eppo-session-assignment-config-loaded';
+export const NULL_SENTINEL = 'EPPO_NULL';
+// number of logging events that may be queued while waiting for initialization
+export const MAX_EVENT_QUEUE_SIZE = 100;