🤖 Merge PR DefinitelyTyped#70345 Add Streams API types for k6 by @joa…

…nlopez

types/k6/experimental/streams.d.ts

@@ -0,0 +1,198 @@
+/**
+ * This module provides an experimental implementation of the Streams API
+ * for k6.
+ *
+ * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/
+ */
+
+/**
+ * The ReadableStream object provides the API for creating and managing readable
+ * streams of raw data, bit by bit, as soon as it is available, without needing to generate a buffer, string, or blob.
+ */
+export class ReadableStream {
+    /**
+     * The ReadableStream constructor returns a newly created ReadableStream object.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestream/
+     *
+     * @param underlyingSource - defines the source of data for the stream.
+     * @param queuingStrategy - defines the queuing strategy to adopt for the stream.
+     */
+    constructor(underlyingSource?: UnderlyingSource, queuingStrategy?: QueuingStrategy);
+
+    /**
+     * Closes the stream and signals a reason for the closure.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestream/cancel/
+     *
+     * Used when you’ve completely finished with the stream and don’t need any more data from it,
+     * even if chunks are enqueued waiting to be read.
+     *
+     * That data is lost after cancel is called, and the stream is not readable anymore.
+     * To close the stream without getting rid of enqueued chunks, use `ReadableStreamDefaultController.close()`.
+     *
+     * It returns a promise that is resolved with `undefined` when the stream is canceled.
+     *
+     * @param reason - the reason for canceling the stream.
+     */
+    cancel(reason: any): Promise<void>;
+
+    /**
+     * Creates a reader and locks the stream to it.
+     * While the stream is locked, no other reader can be acquired until this one is released.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestream/getreader/
+     */
+    getReader(): ReadableStreamDefaultReader;
+}
+
+/**
+ * The object that defines the source of data for the stream.
+ */
+export interface UnderlyingSource {
+    /**
+     * Called when the stream is created.
+     * It can be used to perform any setup tasks.
+     * The content of this method is to be defined by the user.
+     */
+    start?: (controller: ReadableStreamDefaultController) => void | Promise<void>;
+
+    /**
+     * Called repeatedly to fetch and queue data into the stream,
+     * until it reaches its high watermark.
+     * If `pull()` returns a promise, it won’t be called again until the promise is resolved.
+     */
+    pull?: (controller: ReadableStreamDefaultController) => void | Promise<void>;
+
+    /**
+     * Called when the stream is canceled.
+     * It can be used to release access to the stream source and perform any cleanup tasks.
+     * The reason parameter passed to this method is an optional human-readable value
+     * that represents the reason for canceling the stream.
+     */
+    cancel?: (reason?: any) => void | Promise<void>;
+
+    /**
+     * Specifies the type of the underlying source.
+     * It can currently only receive the value 'default' which is its default value.
+     */
+    type?: "default";
+}
+
+/**
+ * The object that allows the user to control a ReadableStream’s state and internal queue.
+ * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestreamdefaultcontroller/
+ */
+export interface ReadableStreamDefaultController {
+    /**
+     * Closes the associated stream.
+     * Readers can still read any previously enqueued chunks from the stream.
+     * Once those chunks are read, the stream closes, and no more data is available.
+     */
+    close: () => void;
+
+    /**
+     * Enqueues a chunk of data into the associated stream.
+     */
+    enqueue: (chunk: any) => void;
+
+    /**
+     * Makes any future interactions with the associated stream to error.
+     */
+    error: (reason: any) => void;
+}
+
+/**
+ * The object that defines the queuing strategy to adopt for the stream.
+ *
+ * Although the user can define a custom queueing strategy, the default behavior and recommended way
+ * to use the `ReadableStream` is to use a `CountQueuingStrategy` object.
+ */
+export interface QueuingStrategy {
+    /**
+     * Represents the maximum number of chunks that the stream can hold in its internal queue.
+     * The default value is 1.
+     */
+    highWaterMark?: number;
+
+    /**
+     * Returns the size of the chunk passed as an argument.
+     * The default value is a function that returns 1.
+     */
+    size?(chunk: any): number;
+}
+
+/**
+ * The CountQueuingStrategy object is the default QueuingStrategy for ReadableStream.
+ * It counts the number of chunks in the queue.
+ */
+export class CountQueuingStrategy {
+    /**
+     * The CountQueuingStrategy constructor returns a newly created CountQueuingStrategy object.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestream/countqueuingstrategy/
+     *
+     * @param options - an object with optional property `highWaterMark` that determines
+     * the maximum number of chunks that the queue can contain.
+     */
+    constructor(options?: { highWaterMark?: number });
+
+    /**
+     * Represents the maximum number of chunks that the stream can hold in its internal queue.
+     * The default value is 1.
+     */
+    readonly highWaterMark: number;
+
+    /**
+     * Returns the size of the chunk passed as an argument.
+     * The default value is a function that returns 1.
+     */
+    size(chunk: any): number;
+}
+
+/**
+ * The object used to read stream data.
+ * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestreamdefaultreader/
+ */
+export class ReadableStreamDefaultReader {
+    /**
+     * The ReadableStreamDefaultReader constructor returns a newly created ReadableStreamDefaultReader object.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestreamdefaultreader/
+     *
+     * @param stream - defines the stream the reader will own.
+     */
+    constructor(stream: ReadableStream);
+
+    /**
+     * Closes the reader and signals a reason for the closure.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestreamdefaultreader/cancel/
+     *
+     * Used when you’ve completely finished with the stream and don’t need any more data from it,
+     * even if chunks are enqueued waiting to be read.
+     * That data is lost after cancel is called, and the stream is not readable anymore.
+     * To close the stream without getting rid of enqueued chunks, use `ReadableStreamDefaultController.close()`.
+     *
+     * It returns a promise that is resolved with `undefined` when the stream is canceled.
+     *
+     * @param reason - the reason for canceling the stream.
+     */
+    cancel(reason: any): Promise<void>;
+
+    /**
+     * Returns a promise providing access to the next chunk in the stream’s internal queue.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestreamdefaultreader/read/
+     *
+     * - If the stream is closed and no more data is available, the promise resolves with an object of the form:
+     *   `{ done: true, value: undefined }`.
+     * - If the stream is errored, the promise rejects with the error that caused the stream to error.
+     */
+    read(): Promise<{ done: false; value: any } | { done: true; value: undefined }>;
+
+    /**
+     * Releases the reader’s lock on the stream.
+     * https://grafana.com/docs/k6/latest/javascript-api/k6-experimental/streams/readablestreamdefaultreader/releaselock/
+     *
+     * If the associated stream is errored as the lock is released, the reader will be errored as well.
+     * This method is useful when done with the stream and want to release the lock on it.
+     *
+     * If the reader’s lock is released as pending read operations are still in progress,
+     * the reader’s `ReadableStreamDefaultReader.read()` calls are immediately rejected with a `TypeError`.
+     */
+    readonly releaseLock: () => void;
+}

types/k6/experimental/websockets.d.ts

@@ -1,4 +1,5 @@
 import { CookieJar } from "../http";
+import { ReadableStream } from "./streams";
 
 /**
  * This module provides an experimental implementation of the WebSocket API
@@ -139,6 +140,7 @@ export class Blob {
     arrayBuffer(): Promise<ArrayBuffer>;
     bytes(): Promise<Uint8Array>;
     slice(start?: number, end?: number): Blob;
+    stream(): ReadableStream;
     text(): Promise<string>;
 }
 

types/k6/test/experimental/streams.ts

@@ -0,0 +1,117 @@
+import { CountQueuingStrategy, ReadableStream, ReadableStreamDefaultReader } from "k6/experimental/streams";
+
+//
+// ReadableStream constructor
+//
+new ReadableStream();
+new ReadableStream({}, {});
+new ReadableStream({}, new CountQueuingStrategy());
+new ReadableStream({
+    start: _ => {
+    },
+    pull: _ => {
+    },
+    cancel: _ => {
+    },
+    type: "default",
+}, {});
+new ReadableStream({
+    start: _ => {
+    },
+    pull: _ => {
+    },
+    cancel: _ => {
+    },
+    type: "default",
+}, {
+    highWaterMark: 5,
+    size: _ => {
+        return 1;
+    },
+});
+new ReadableStream({
+    // @ts-expect-error
+    type: "byob",
+}, {});
+new ReadableStream({}, {
+    // @ts-expect-error
+    size: _ => {
+    },
+});
+
+const rs = new ReadableStream();
+
+//
+// ReadableStream.cancel
+//
+// @ts-expect-error
+rs.cancel();
+rs.cancel("reason"); // $ExpectType Promise<void>;
+// @ts-expect-error
+rs.cancel = () => {};
+
+//
+// ReadableStream.getReader
+//
+rs.getReader(); // $ExpectType ReadableStreamDefaultReader;
+// @ts-expect-error
+rs.getReader = () => {};
+
+//
+// ReadableStreamDefaultReader constructor
+//
+// @ts-expect-error
+new ReadableStreamDefaultReader();
+const reader = new ReadableStreamDefaultReader(new ReadableStream());
+
+//
+// ReadableStreamDefaultReader.cancel
+//
+// @ts-expect-error
+reader.cancel();
+reader.cancel("reason"); // $ExpectType Promise<void>;
+// @ts-expect-error
+reader.cancel = () => {};
+
+//
+// ReadableStreamDefaultReader.read
+//
+reader.read(); // $ExpectType Promise<{ done: false; value: any; } | { done: true; value: undefined; }>;
+// @ts-expect-error
+reader.read = () => {};
+
+//
+// ReadableStreamDefaultReader.releaseLock
+//
+reader.releaseLock(); // $ExpectType void;
+// @ts-expect-error
+reader.releaseLock = () => {};
+
+//
+// CountQueuingStrategy constructor
+//
+const cqs = new CountQueuingStrategy();
+new CountQueuingStrategy({});
+new CountQueuingStrategy({ highWaterMark: 5 });
+new CountQueuingStrategy({
+    highWaterMark: 5,
+    // @ts-expect-error
+    size: _ => {
+        return 1;
+    },
+});
+
+//
+// CountQueuingStrategy.highWaterMark
+//
+cqs.highWaterMark; // $ExpectType number
+// @ts-expect-error
+cqs.highWaterMark = 5;
+
+//
+// CountQueuingStrategy.size
+// @ts-expect-error
+cqs.size();
+cqs.size("chunk"); // $ExpectType number;
+// @ts-expect-error
+cqs.size = () => {};

types/k6/test/websockets.ts

@@ -52,6 +52,7 @@ const blob = new Blob(["something"]);
     await blob.text(); // $ExpectType string
     await blob.arrayBuffer(); // $ExpectType ArrayBuffer
     await blob.bytes(); // $ExpectType Uint8Array
+    blob.stream(); // $ExpectType ReadableStream
     blob.slice(10, 2); // $ExpectType Blob
     // @ts-expect-error
     blob.slice(10, 2, "string");

types/k6/tsconfig.json

@@ -35,6 +35,7 @@
         "test/websockets.ts",
         "test/experimental/browser.ts",
         "test/experimental/fs.ts",
+        "test/experimental/streams.ts",
         "test/ws.ts"
     ]
 }