# `@dataverse/toggle-provider`

This package provides a common interface for feature toggle provider functionality as well as default feature toggle provider implementation leveraging Unleash server client.

## Config

| Name            | Description                                                       |
| --------------- | ----------------------------------------------------------------- |
| url             | URL to Unleash server (not proxy but the actual instance)         |
| appName         | app name for browser and metric reasons                           |
| instanceId      | identity the instance                                             |
| apiToken        | token to authorize API requests (taken from Unleash)              |
| logger          | A config for the logger                                           |
| refreshInterval | How often does unleash client refreshes the toggles status        |
| disableMetrics  | Should the client register with the server and send usage metrics |
| environment     | Which environment in Unleash to connect to                        |

For logger configuration properties see the
[logger documentation](https://gitlab.byteprophecy.accenture.com/dataverse/common-nodejs-components/blob/develop/packages/logger/README.md)

## Usage

```typescript
import { UnleashToggleProvider } from '@dataverse/toggle-provider';

const config = {
  url: 'https://URL to your unleash instance/api',
  appName: 'my application',
  instanceId: 'my application instance id',
  apiToken: '*.development.tokenfromunleash',
  logger: { ...loggerConfig },
  refreshInterval: 15000,
  disableMetrics: false,
  environment: 'development',
};

const provider = new UnleashToggleProvider(config);

// Init the instance (optional bootstrap can be provided to load feature config before first api call is done)
await provider.init();

const isEnabled = provider.isEnabled('feature-name-from-unleash');
// console.log(isEnabled) -> false

// Optionally make sure your openapi definition is feature toggled.
// Take a look into ./src/__tests__/fixtures for possible usage.
// Currently object and array object segments can be feature toggled
const openapiSpec = {
  info: {},
  paths: {
    '/users': {
      post: {
        'x-toggle-feature': 'feature-name-from-unleash',
      },
    },
  },
};

const featureToggleUpdatedSpec = this.provider.syncOpenApiSpec(openapiSpec);
// console.log(featureToggleUpdatedSpec) ->
// {
//   info: {},
//   paths: {
//     '/users': {
//       // The whole post object parrent to 'x-toggle-feature' is removed when the feature toggle is disabled
//     },
//   },
// }
```