3.0.0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@push.rocks/smartstream",
-  "version": "2.0.5",
+  "version": "3.0.0",
   "private": false,
   "description": "simplifies access to node streams",
   "main": "dist_ts/index.js",

test/test.streamfunction.ts

@@ -33,9 +33,7 @@ tap.test('should handle a read stream', async (tools) => {
 
 tap.test('should create a valid Intake', async (tools) => {
   testIntake = new smartstream.StreamIntake<string>();
-  testIntake
-    .getReadable()
-    .pipe(
+  testIntake.pipe(
       smartstream.createDuplexStream<string, string>(
         async (chunkString) => {
           await tools.delayFor(100);

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartstream',
-  version: '2.0.5',
+  version: '3.0.0',
   description: 'simplifies access to node streams'
 }

ts/index.ts

@@ -1,3 +1,4 @@
+export * from './smartstream.classes.passthrough.js';
 export * from './smartstream.classes.smartstream.js';
 export * from './smartstream.classes.streamwrapper.js';
 export * from './smartstream.classes.streamintake.js';

ts/smartstream.classes.passthrough.ts

@@ -0,0 +1,19 @@
+import * as plugins from './smartstream.plugins.js';
+
+export class PassThrough extends plugins.stream.Duplex {
+  constructor(options?: plugins.stream.DuplexOptions) {
+    super(options);
+  }
+
+  _read(size: number): void {
+    // No-op: Data written will be automatically available for reading.
+  }
+
+  _write(chunk: any, encoding: BufferEncoding, callback: (error?: Error | null) => void): void {
+    if (this.push(chunk, encoding)) {
+      callback();
+    } else {
+      this.once('drain', callback);
+    }
+  }
+}

ts/smartstream.classes.smartstream.ts

@@ -1,20 +1,35 @@
 import * as plugins from './smartstream.plugins.js';
 import { Duplex, type DuplexOptions } from 'stream';
+export interface SmartStreamOptions<TInput, TOutput> extends DuplexOptions {
+  // You can add more custom options relevant to TInput and TOutput if necessary
+}
 
-export class SmartStream extends Duplex {
+export class SmartStream<TInput = any, TOutput = any> extends Duplex {
   private observableSubscription?: plugins.smartrx.rxjs.Subscription;
+  private asyncChunkModifier?: (chunk: TInput) => Promise<TOutput>;
 
-  constructor(options?: DuplexOptions) {
+  constructor(options?: SmartStreamOptions<TInput, TOutput>, asyncChunkModifierArg?: (chunk: TInput) => Promise<TOutput>) {
     super(options);
+    this.asyncChunkModifier = asyncChunkModifierArg;
   }
 
-  _read(size: number) {
-    // Implement if you need custom behavior, otherwise leave it empty
-  }
-
-  _write(chunk: any, encoding: string, callback: (error?: Error | null) => void) {
-    // Implement if you need custom behavior
-    callback();
+  // Ensure the _write method types the chunk as TInput and encodes TOutput
+  public async _write(chunk: TInput, encoding: string, callback: (error?: Error | null) => void) {
+    try {
+      if (this.asyncChunkModifier) {
+        const modifiedChunk = await this.asyncChunkModifier(chunk);
+        if (!this.push(modifiedChunk)) {
+          // Handle backpressure here if necessary
+        }
+      } else {
+        if (!this.push(chunk as unknown as TOutput)) {
+          // Handle backpressure here if necessary
+        }
+      }
+      callback();
+    } catch (err) {
+      callback(err);
+    }
   }
 
   static fromBuffer(buffer: Buffer, options?: DuplexOptions): SmartStream {
@@ -52,4 +67,46 @@ export class SmartStream extends Duplex {
 
     return smartStream;
   }
+
+  static fromReplaySubject(replaySubject: plugins.smartrx.rxjs.ReplaySubject<any>, options?: DuplexOptions): SmartStream {
+    const smartStream = new SmartStream(options);
+    let isBackpressured = false;
+
+    // Subscribe to the ReplaySubject
+    const subscription = replaySubject.subscribe({
+      next: (data) => {
+        const canPush = smartStream.push(data);
+        if (!canPush) {
+          // If push returns false, pause the subscription because of backpressure
+          isBackpressured = true;
+          subscription.unsubscribe();
+        }
+      },
+      error: (err) => {
+        smartStream.emit('error', err);
+      },
+      complete: () => {
+        smartStream.push(null); // End the stream when the ReplaySubject completes
+      }
+    });
+
+    // Listen for 'drain' event to resume the subscription if it was paused
+    smartStream.on('drain', () => {
+      if (isBackpressured) {
+        isBackpressured = false;
+        // Resubscribe to the ReplaySubject since we previously paused
+        smartStream.observableSubscription = replaySubject.subscribe({
+          next: (data) => {
+            if (!smartStream.push(data)) {
+              smartStream.observableSubscription?.unsubscribe();
+              isBackpressured = true;
+            }
+          },
+          // No need to repeat error and complete handling here because it's already set up above
+        });
+      }
+    });
+
+    return smartStream;
+  }
 }

ts/smartstream.classes.streamintake.ts

@@ -1,56 +1,42 @@
 import * as plugins from './smartstream.plugins.js';
 
-export class StreamIntake<T> {
+export class StreamIntake<T> extends plugins.stream.Readable {
   private signalEndBoolean = false;
   private chunkStore: T[] = [];
-
   public pushNextObservable = new plugins.smartrx.ObservableIntake<any>();
-
   private pushedNextDeferred = plugins.smartpromise.defer();
 
-  private readableStream = plugins.from2.obj(async (size, next) => {
+  constructor(options?: plugins.stream.ReadableOptions) {
+    super({ ...options, objectMode: true }); // Ensure that we are in object mode.
+    this.pushNextObservable.push('please push next');
+  }
+
+  _read(size: number): void {
     // console.log('get next');
-    // execute without backpressure
-    while (this.chunkStore.length > 0) {
-      next(null, this.chunkStore.shift());
-    }
-    if (this.signalEndBoolean) {
-      next(null, null);
-    }
+    const pushChunk = (): void => {
+      if (this.chunkStore.length > 0) {
+        // If push returns false, then we should stop reading
+        if (!this.push(this.chunkStore.shift())) {
+          return;
+        }
+      }
 
-    // lets trigger backpressure handling
-    this.pushNextObservable.push('please push next');
-    await this.pushedNextDeferred.promise;
-    this.pushedNextDeferred = plugins.smartpromise.defer();
+      if (this.chunkStore.length === 0) {
+        if (this.signalEndBoolean) {
+          // If we're done, push null to signal the end of the stream
+          this.push(null);
+        } else {
+          // Ask for more data and wait
+          this.pushNextObservable.push('please push next');
+          this.pushedNextDeferred.promise.then(() => {
+            this.pushedNextDeferred = plugins.smartpromise.defer(); // Reset the deferred
+            pushChunk(); // Try pushing the next chunk
+          });
+        }
+      }
+    };
 
-    // execute with backpressure
-    while (this.chunkStore.length > 0) {
-      next(null, this.chunkStore.shift());
-    }
-    if (this.signalEndBoolean) {
-      next(null, null);
-    }
-  });
-
-  constructor() {
-    this.pushNextObservable.push('please push next');
-  }
-
-  /**
-   * returns a new style readble stream
-   */
-  public getReadable() {
-    const readable = new plugins.stream.Readable({
-      objectMode: true,
-    });
-    return readable.wrap(this.readableStream);
-  }
-
-  /**
-   * returns an oldstyle readble stream
-   */
-  public getReadableStream() {
-    return this.readableStream;
+    pushChunk();
   }
 
   public pushData(chunkData: T) {