Merge pull request #180 from alubbe/easier-async-iteration

Add forceStream option

README.md

@@ -27,7 +27,7 @@ There are no added compiled dependencies - inflation is handled by node.js's bui
 
 Please note:  Methods that use the Central Directory instead of parsing entire file can be found under [`Open`](#open)
 
-Chrome extension files (.crx) are zipfiles with an [extra header](http://www.adambarth.com/experimental/crx/docs/crx.html) at the start of the file.  Unzipper will parse .crx file with the streaming methods (`Parse` and `ParseOne`).  The `Open` methods will check for `crx` headers and parse crx files, but only if you provide `crx: true` in options.  
+Chrome extension files (.crx) are zipfiles with an [extra header](http://www.adambarth.com/experimental/crx/docs/crx.html) at the start of the file.  Unzipper will parse .crx file with the streaming methods (`Parse` and `ParseOne`).  The `Open` methods will check for `crx` headers and parse crx files, but only if you provide `crx: true` in options.
 
 ## Installation
 
@@ -62,7 +62,6 @@ entry.autodrain().on('error' => handleError);
 
 Here is a quick example:
 
-
 ```js
 fs.createReadStream('path/to/archive.zip')
   .pipe(unzipper.Parse())
@@ -77,6 +76,23 @@ fs.createReadStream('path/to/archive.zip')
     }
   });
 ```
+
+and the same example using async iterators:
+
+```js
+const zip = fs.createReadStream('path/to/archive.zip').pipe(unzipper.Parse({forceStream: true}));
+for await (const entry of zip) {
+  const fileName = entry.path;
+  const type = entry.type; // 'Directory' or 'File'
+  const size = entry.vars.uncompressedSize; // There is also compressedSize;
+  if (fileName === "this IS the file I'm looking for") {
+    entry.pipe(fs.createWriteStream('output/path'));
+  } else {
+    entry.autodrain();
+  }
+}
+```
+
 ### Parse zip by piping entries downstream
 
 If you `pipe` from unzipper the downstream components will receive each `entry` for further processing.   This allows for clean pipelines transforming zipfiles into unzipped data.

lib/parse.js

@@ -74,7 +74,7 @@ Parse.prototype._readCrxHeader = function() {
       .word32lu('version')
       .word32lu('pubKeyLength')
       .word32lu('signatureLength')
-      .vars;  
+      .vars;
     return self.pull(self.crxHeader.pubKeyLength + self.crxHeader.signatureLength);
   }).then(function(data) {
     self.crxHeader.publicKey = data.slice(0,self.crxHeader.pubKeyLength);
@@ -108,7 +108,7 @@ Parse.prototype._readFile = function () {
       var fileName = fileNameBuffer.toString('utf8');
       var entry = Stream.PassThrough();
       var __autodraining = false;
-      
+
       entry.autodrain = function() {
         __autodraining = true;
         var draining = entry.pipe(NoopStream());
@@ -145,17 +145,21 @@ Parse.prototype._readFile = function () {
           }
         }
       }
-       
+
       return self.pull(vars.extraFieldLength).then(function(extraField) {
         var extra = parseExtraField(extraField, vars);
 
         entry.vars = vars;
         entry.extra = extra;
 
-        self.emit('entry', entry);
-
-        if (self._readableState.pipesCount || (self._readableState.pipes && self._readableState.pipes.length))
+        if (self._opts.forceStream) {
           self.push(entry);
+        } else {
+          self.emit('entry', entry);
+
+          if (self._readableState.pipesCount || (self._readableState.pipes && self._readableState.pipes.length))
+            self.push(entry);
+        }
 
         if (self._opts.verbose)
           console.log({
@@ -212,7 +216,7 @@ Parse.prototype._processDataDescriptor = function (entry) {
 Parse.prototype._readCentralDirectoryFileHeader = function () {
   var self = this;
   return self.pull(42).then(function(data) {
-    
+
     var vars = binary.parse(data)
       .word16lu('versionMadeBy')
       .word16lu('versionsNeededToExtract')
@@ -248,7 +252,7 @@ Parse.prototype._readCentralDirectoryFileHeader = function () {
 Parse.prototype._readEndOfCentralDirectoryRecord = function() {
   var self = this;
   return self.pull(18).then(function(data) {
-    
+
     var vars = binary.parse(data)
       .word16lu('diskNumber')
       .word16lu('diskStart')
@@ -264,7 +268,7 @@ Parse.prototype._readEndOfCentralDirectoryRecord = function() {
       self.end();
       self.push(null);
     });
-    
+
   });
 };
 

test/forceStream.js

@@ -0,0 +1,32 @@
+'use strict';
+
+var test = require('tap').test;
+var fs = require('fs');
+var path = require('path');
+var Stream = require('stream');
+var unzip = require('../');
+
+// Backwards compatibility for node versions < 8
+if (!Stream.Writable || !Stream.Writable.prototype.destroy)
+  Stream = require('readable-stream');
+
+test("verify that setting the forceStream option emits a data event instead of entry", function (t) {
+  var archive = path.join(__dirname, '../testData/compressed-standard/archive.zip');
+
+  var dataEventEmitted = false;
+  var entryEventEmitted = false;
+  fs.createReadStream(archive)
+    .pipe(unzip.Parse({ forceStream: true }))
+    .on('data', function(entry) {
+      t.equal(entry instanceof Stream.PassThrough, true);
+      dataEventEmitted = true;
+    })
+    .on('entry', function() {
+      entryEventEmitted = true;
+    })
+      .on('finish', function() {
+      t.equal(dataEventEmitted, true);
+      t.equal(entryEventEmitted, false);
+      t.end();
+    });
+});