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diff --git a/docs/api/RetryHandler.md b/docs/api/RetryHandler.md new file mode 100644 index 0000000..2323ce4 --- /dev/null +++ b/docs/api/RetryHandler.md @@ -0,0 +1,108 @@ +# Class: RetryHandler + +Extends: `undici.DispatcherHandlers` + +A handler class that implements the retry logic for a request. + +## `new RetryHandler(dispatchOptions, retryHandlers, [retryOptions])` + +Arguments: + +- **options** `Dispatch.DispatchOptions & RetryOptions` (required) - It is an intersection of `Dispatcher.DispatchOptions` and `RetryOptions`. +- **retryHandlers** `RetryHandlers` (required) - Object containing the `dispatch` to be used on every retry, and `handler` for handling the `dispatch` lifecycle. + +Returns: `retryHandler` + +### Parameter: `Dispatch.DispatchOptions & RetryOptions` + +Extends: [`Dispatch.DispatchOptions`](Dispatcher.md#parameter-dispatchoptions). + +#### `RetryOptions` + +- **retry** `(err: Error, context: RetryContext, callback: (err?: Error | null) => void) => void` (optional) - Function to be called after every retry. It should pass error if no more retries should be performed. +- **maxRetries** `number` (optional) - Maximum number of retries. Default: `5` +- **maxTimeout** `number` (optional) - Maximum number of milliseconds to wait before retrying. Default: `30000` (30 seconds) +- **minTimeout** `number` (optional) - Minimum number of milliseconds to wait before retrying. Default: `500` (half a second) +- **timeoutFactor** `number` (optional) - Factor to multiply the timeout by for each retry attempt. Default: `2` +- **retryAfter** `boolean` (optional) - It enables automatic retry after the `Retry-After` header is received. Default: `true` +- +- **methods** `string[]` (optional) - Array of HTTP methods to retry. Default: `['GET', 'PUT', 'HEAD', 'OPTIONS', 'DELETE']` +- **statusCodes** `number[]` (optional) - Array of HTTP status codes to retry. Default: `[429, 500, 502, 503, 504]` +- **errorCodes** `string[]` (optional) - Array of Error codes to retry. Default: `['ECONNRESET', 'ECONNREFUSED', 'ENOTFOUND', 'ENETDOWN','ENETUNREACH', 'EHOSTDOWN', + +**`RetryContext`** + +- `state`: `RetryState` - Current retry state. It can be mutated. +- `opts`: `Dispatch.DispatchOptions & RetryOptions` - Options passed to the retry handler. + +### Parameter `RetryHandlers` + +- **dispatch** `(options: Dispatch.DispatchOptions, handlers: Dispatch.DispatchHandlers) => Promise<Dispatch.DispatchResponse>` (required) - Dispatch function to be called after every retry. +- **handler** Extends [`Dispatch.DispatchHandlers`](Dispatcher.md#dispatcherdispatchoptions-handler) (required) - Handler function to be called after the request is successful or the retries are exhausted. + +Examples: + +```js +const client = new Client(`http://localhost:${server.address().port}`); +const chunks = []; +const handler = new RetryHandler( + { + ...dispatchOptions, + retryOptions: { + // custom retry function + retry: function (err, state, callback) { + counter++; + + if (err.code && err.code === "UND_ERR_DESTROYED") { + callback(err); + return; + } + + if (err.statusCode === 206) { + callback(err); + return; + } + + setTimeout(() => callback(null), 1000); + }, + }, + }, + { + dispatch: (...args) => { + return client.dispatch(...args); + }, + handler: { + onConnect() {}, + onBodySent() {}, + onHeaders(status, _rawHeaders, resume, _statusMessage) { + // do something with headers + }, + onData(chunk) { + chunks.push(chunk); + return true; + }, + onComplete() {}, + onError() { + // handle error properly + }, + }, + } +); +``` + +#### Example - Basic RetryHandler with defaults + +```js +const client = new Client(`http://localhost:${server.address().port}`); +const handler = new RetryHandler(dispatchOptions, { + dispatch: client.dispatch.bind(client), + handler: { + onConnect() {}, + onBodySent() {}, + onHeaders(status, _rawHeaders, resume, _statusMessage) {}, + onData(chunk) {}, + onComplete() {}, + onError(err) {}, + }, +}); +``` |