Improve stream detection to allow Stream-like interfaces (#179)

* expand stream test

* add is-stream@^2.0.0

* use isStream

* rework test

lib/archivers/archive-output-stream.js

@@ -6,6 +6,7 @@
  * https://github.com/archiverjs/node-compress-commons/blob/master/LICENSE-MIT
  */
 var inherits = require('util').inherits;
+var isStream = require('is-stream');
 var Transform = require('readable-stream').Transform;
 
 var ArchiveEntry = require('./archive-entry');
@@ -84,7 +85,7 @@ ArchiveOutputStream.prototype.entry = function(ae, source, callback) {
 
   if (Buffer.isBuffer(source)) {
     this._appendBuffer(ae, source, callback);
-  } else if (util.isStream(source)) {
+  } else if (isStream(source)) {
     this._appendStream(ae, source, callback);
   } else {
     this._archive.processing = false;

lib/util/index.js

@@ -7,19 +7,16 @@
  */
 var Stream = require('stream').Stream;
 var PassThrough = require('readable-stream').PassThrough;
+var isStream = require('is-stream');
 
 var util = module.exports = {};
 
-util.isStream = function(source) {
-  return source instanceof Stream;
-};
-
 util.normalizeInputSource = function(source) {
   if (source === null) {
     return Buffer.alloc(0);
   } else if (typeof source === 'string') {
     return Buffer.from(source);
-  } else if (util.isStream(source) && !source._readableState) {
+  } else if (isStream(source) && !source._readableState) {
     var normalized = new PassThrough();
     source.pipe(normalized);
 

package.json

@@ -28,6 +28,7 @@
   "dependencies": {
     "crc-32": "^1.2.0",
     "crc32-stream": "^6.0.0",
+    "is-stream": "^2.0.1",
     "normalize-path": "^3.0.0",
     "readable-stream": "^4.0.0"
   },

test/zip-archive-output-stream.js

@@ -3,6 +3,7 @@ var fs = require('fs');
 var stream = require('stream');
 var assert = require('chai').assert;
 var mkdir = require('mkdirp');
+var Readable = require('readable-stream').Readable;
 
 var helpers = require('./helpers');
 var WriteHashStream = helpers.WriteHashStream;
@@ -48,6 +49,20 @@ describe('ZipArchiveOutputStream', function() {
       archive.entry(entry, fs.createReadStream('test/fixtures/test.txt')).finish();
     });
 
+    it('should append Stream-like sources', function(done) {
+      var archive = new ZipArchiveOutputStream();
+      var testStream = new WriteHashStream('tmp/zip-stream-like.zip');
+      var entry = new ZipArchiveEntry('stream-like.txt');
+
+      testStream.on('close', function() {
+        done();
+      });
+
+      archive.pipe(testStream);
+
+      archive.entry(entry, Readable.from(['test'])).finish();
+    });
+
     it('should stop streaming on Stream error', function(done) {
       var archive = new ZipArchiveOutputStream();
       var testStream = new WriteHashStream('tmp/zip-stream.zip');
@@ -129,4 +144,4 @@ describe('ZipArchiveOutputStream', function() {
     });
   });
 
-});
+});