feat(smartduplex): improve backpressure handling and web/node stream interoperability

test/test.streamintake.ts

@@ -0,0 +1,128 @@
+import { expect, tap } from '@push.rocks/tapbundle';
+import * as fs from 'fs';
+import { StreamIntake, SmartDuplex } from '../ts/index.js';
+import * as stream from 'stream';
+
+// =============================================
+// Basic StreamIntake
+// =============================================
+
+tap.test('StreamIntake: should push data and signal end', async (tools) => {
+  const intake = new StreamIntake<string>();
+  const results: string[] = [];
+
+  intake.pipe(
+    new SmartDuplex<string, string>({
+      objectMode: true,
+      writeFunction: async (chunk) => {
+        results.push(chunk);
+        return chunk;
+      },
+    })
+  );
+
+  const done = tools.defer();
+  let counter = 0;
+  intake.pushNextObservable.subscribe(() => {
+    if (counter < 5) {
+      counter++;
+      intake.pushData(`item-${counter}`);
+    } else {
+      intake.signalEnd();
+      done.resolve();
+    }
+  });
+
+  await done.promise;
+  // Give streams time to flush
+  await new Promise((resolve) => setTimeout(resolve, 100));
+  expect(results.length).toBeGreaterThan(0);
+});
+
+tap.test('StreamIntake: should pipe to a writable', async (tools) => {
+  const intake = new StreamIntake<string>();
+
+  intake
+    .pipe(
+      new SmartDuplex({
+        objectMode: true,
+        writeFunction: async (chunk: string) => {
+          return chunk;
+        },
+      })
+    )
+    .pipe(fs.createWriteStream('./test/assets/writabletext.txt'));
+
+  const done = tools.defer();
+  let counter = 0;
+  intake.pushNextObservable.subscribe(() => {
+    if (counter < 10) {
+      counter++;
+      intake.pushData('data\n');
+    } else {
+      intake.signalEnd();
+      done.resolve();
+    }
+  });
+
+  await done.promise;
+});
+
+// =============================================
+// StreamIntake.fromStream (Node Readable)
+// =============================================
+
+tap.test('StreamIntake: fromStream should wrap a Node readable', async (tools) => {
+  const nodeReadable = fs.createReadStream('./test/assets/readabletext.txt');
+  const intake = await StreamIntake.fromStream<Buffer>(nodeReadable);
+
+  const chunks: Buffer[] = [];
+  const done = tools.defer();
+
+  intake.on('data', (chunk: Buffer) => {
+    chunks.push(chunk);
+  });
+
+  intake.on('end', () => {
+    expect(chunks.length).toBeGreaterThan(0);
+    const content = Buffer.concat(chunks).toString();
+    expect(content.length).toBeGreaterThan(0);
+    done.resolve();
+  });
+
+  await done.promise;
+});
+
+// =============================================
+// StreamIntake.fromStream (Web ReadableStream)
+// =============================================
+
+tap.test('StreamIntake: fromStream should wrap a Web ReadableStream', async (tools) => {
+  const data = ['chunk1', 'chunk2', 'chunk3'];
+  const webReadable = new ReadableStream<string>({
+    start(controller) {
+      for (const item of data) {
+        controller.enqueue(item);
+      }
+      controller.close();
+    },
+  });
+
+  const intake = await StreamIntake.fromStream<string>(webReadable);
+
+  const results: string[] = [];
+  const done = tools.defer();
+
+  intake.on('data', (chunk: string) => {
+    results.push(chunk);
+  });
+
+  intake.on('end', () => {
+    expect(results).toEqual(data);
+    done.resolve();
+  });
+
+  await done.promise;
+});
+
+export default tap.start();