Add TransformStream and TransformStreamController (denoland#5042)

cli/js/globals.ts

@@ -23,6 +23,7 @@ import * as workers from "./web/workers.ts";
 import * as performanceUtil from "./web/performance.ts";
 import * as request from "./web/request.ts";
 import * as readableStream from "./web/streams/readable_stream.ts";
+import * as transformStream from "./web/streams/transform_stream.ts";
 import * as queuingStrategy from "./web/streams/queuing_strategy.ts";
 import * as writableStream from "./web/streams/writable_stream.ts";
 
@@ -234,6 +235,7 @@ export const windowOrWorkerGlobalScopeProperties = {
  TextEncoder: nonEnumerable(textEncoding.TextEncoder),
  TextDecoder: nonEnumerable(textEncoding.TextDecoder),
  ReadableStream: nonEnumerable(readableStream.ReadableStreamImpl),
+ TransformStream: nonEnumerable(transformStream.TransformStreamImpl),
  Request: nonEnumerable(request.Request),
  Response: nonEnumerable(fetchTypes.Response),
  performance: writable(new performanceUtil.Performance()),

cli/js/lib.deno.shared_globals.d.ts

@@ -423,6 +423,42 @@ interface WritableStreamDefaultWriter<W = any> {
  write(chunk: W): Promise<void>;
 }
 
+declare class TransformStream<I = any, O = any> {
+ constructor(
+ transformer?: Transformer<I, O>,
+ writableStrategy?: QueuingStrategy<I>,
+ readableStrategy?: QueuingStrategy<O>
+ );
+ readonly readable: ReadableStream<O>;
+ readonly writable: WritableStream<I>;
+}
+
+interface TransformStreamDefaultController<O = any> {
+ readonly desiredSize: number | null;
+ enqueue(chunk: O): void;
+ error(reason?: any): void;
+ terminate(): void;
+}
+
+interface Transformer<I = any, O = any> {
+ flush?: TransformStreamDefaultControllerCallback<O>;
+ readableType?: undefined;
+ start?: TransformStreamDefaultControllerCallback<O>;
+ transform?: TransformStreamDefaultControllerTransformCallback<I, O>;
+ writableType?: undefined;
+}
+
+interface TransformStreamDefaultControllerCallback<O> {
+ (controller: TransformStreamDefaultController<O>): void | PromiseLike<void>;
+}
+
+interface TransformStreamDefaultControllerTransformCallback<I, O> {
+ (
+ chunk: I,
+ controller: TransformStreamDefaultController<O>
+ ): void | PromiseLike<void>;
+}
+
 interface DOMStringList {
  /** Returns the number of strings in strings. */
  readonly length: number;