Fix pipeing a Web Stream to an ArrayStream

lib/streams.js

@@ -110,7 +110,7 @@ async function pipe(input, target, {
   preventAbort = false,
   preventCancel = false
 } = {}) {
-  if (isStream(input) && !isArrayStream(input)) {
+  if (isStream(input) && !isArrayStream(input) && !isArrayStream(target)) {
     input = toStream(input);
     try {
       if (input[externalBuffer]) {
@@ -129,7 +129,9 @@ async function pipe(input, target, {
     } catch(e) {}
     return;
   }
-  input = toArrayStream(input);
+  if (!isStream(input)) {
+    input = toArrayStream(input);
+  }
   const reader = getReader(input);
   const writer = getWriter(target);
   try {
@@ -566,6 +568,7 @@ function getWriter(input) {
 export {
   ArrayStream,
   toStream,
+  toArrayStream,
   concatStream,
   concat,
   getReader,

test/common.test.ts

@@ -1,5 +1,6 @@
 import { expect } from 'chai';
-import { toStream, readToEnd, slice } from  '@openpgp/web-stream-tools';
+// @ts-ignore Missing type definitions
+import { toStream, toArrayStream, readToEnd, slice, pipe, ArrayStream } from '@openpgp/web-stream-tools';
 
 describe('Common integration tests', () => {
   it('toStream/readToEnd', async () => {
@@ -13,5 +14,37 @@ describe('Common integration tests', () => {
     const streamedData = toStream(input);
     const slicedStream = slice(streamedData, 8);
     expect(await readToEnd(slicedStream)).to.equal('chunk');
-  })
-})
+  });
+
+  it('pipe from stream to stream', async () => {
+    const input = 'chunk';
+    const inputStream = toStream(input);
+    const outputStream = new TransformStream();
+    pipe(inputStream, outputStream.writable);
+    expect(await readToEnd(outputStream.readable)).to.equal('chunk');
+  });
+
+  it('pipe from stream to arraystream', async () => {
+    const input = 'chunk';
+    const inputStream = toStream(input);
+    const outputStream = new ArrayStream();
+    pipe(inputStream, outputStream);
+    expect(await readToEnd(outputStream)).to.equal('chunk');
+  });
+
+  it('pipe from arraystream to stream', async () => {
+    const input = 'chunk';
+    const inputStream = toArrayStream(input);
+    const outputStream = new TransformStream();
+    pipe(inputStream, outputStream.writable);
+    expect(await readToEnd(outputStream.readable)).to.equal('chunk');
+  });
+
+  it('pipe from arraystream to arraystream', async () => {
+    const input = 'chunk';
+    const inputStream = toArrayStream(input);
+    const outputStream = new ArrayStream();
+    pipe(inputStream, outputStream);
+    expect(await readToEnd(outputStream)).to.equal('chunk');
+  });
+});