Support for archive + file comments

README.md

@@ -63,6 +63,7 @@ File paths must not end with `"/"`.
   mode: stats.mode,
   compress: true,
   forceZip64Format: false,
+  fileComment: ""
 }
 ```
 
@@ -97,6 +98,7 @@ See `addFile()` for info about the `metadataPath` parameter.
   mode: 0o100664,
   compress: true,
   forceZip64Format: false,
+  fileComment: "",
   size: 12345, // example value
 }
 ```
@@ -121,6 +123,7 @@ See `addFile()` for info about the `metadataPath` parameter.
   mode: 0o100664,
   compress: true,
   forceZip64Format: false,
+  fileComment: ""
 }
 ```
 
@@ -182,6 +185,7 @@ and causes the eventual close of `outputStream`.
 
 ```js
 {
+  comment: "",
   forceZip64Format: false,
 }
 ```

index.js

@@ -118,6 +118,7 @@ ZipFile.prototype.end = function(options, finalSizeCallback) {
   this.ended = true;
   this.finalSizeCallback = finalSizeCallback;
   this.forceZip64Eocd = !!options.forceZip64Format;
+  this.comment = Buffer.from(options.comment || "", "utf-8");
   pumpEntries(this);
 };
 
@@ -226,7 +227,7 @@ function calculateFinalSize(self) {
       }
     }
 
-    centralDirectorySize += CENTRAL_DIRECTORY_RECORD_FIXED_SIZE + entry.utf8FileName.length;
+    centralDirectorySize += CENTRAL_DIRECTORY_RECORD_FIXED_SIZE + entry.utf8FileName.length + entry.fileComment.length;
     if (useZip64Format) {
       centralDirectorySize += ZIP64_EXTENDED_INFORMATION_EXTRA_FIELD_SIZE;
     }
@@ -240,7 +241,7 @@ function calculateFinalSize(self) {
     // use zip64 end of central directory stuff
     endOfCentralDirectorySize += ZIP64_END_OF_CENTRAL_DIRECTORY_RECORD_SIZE + ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR_SIZE;
   }
-  endOfCentralDirectorySize += END_OF_CENTRAL_DIRECTORY_RECORD_SIZE;
+  endOfCentralDirectorySize += END_OF_CENTRAL_DIRECTORY_RECORD_SIZE + self.comment.length;
   return pretendOutputCursor + centralDirectorySize + endOfCentralDirectorySize;
 }
 
@@ -277,7 +278,7 @@ function getEndOfCentralDirectoryRecord(self, actuallyJustTellMeHowLongItWouldBe
     }
   }
 
-  var eocdrBuffer = Buffer.allocUnsafe(END_OF_CENTRAL_DIRECTORY_RECORD_SIZE);
+  var eocdrBuffer = Buffer.allocUnsafe(END_OF_CENTRAL_DIRECTORY_RECORD_SIZE + self.comment.length);
   // end of central dir signature                       4 bytes  (0x06054b50)
   eocdrBuffer.writeUInt32LE(0x06054b50, 0);
   // number of this disk                                2 bytes
@@ -293,9 +294,9 @@ function getEndOfCentralDirectoryRecord(self, actuallyJustTellMeHowLongItWouldBe
   // offset of start of central directory with respect to the starting disk number  4 bytes
   eocdrBuffer.writeUInt32LE(normalOffsetOfStartOfCentralDirectory, 16);
   // .ZIP file comment length                           2 bytes
-  eocdrBuffer.writeUInt16LE(0, 20);
+  eocdrBuffer.writeUInt16LE(self.comment.length, 20);
   // .ZIP file comment                                  (variable size)
-  // no comment
+  self.comment.copy(eocdrBuffer, 22);
 
   if (!needZip64Format) return eocdrBuffer;
 
@@ -392,6 +393,7 @@ function Entry(metadataPath, isDirectory, options) {
     if (options.compress != null) this.compress = !!options.compress;
   }
   this.forceZip64Format = !!options.forceZip64Format;
+  this.fileComment = Buffer.from(options.fileComment || "", "utf-8");
 }
 Entry.WAITING_FOR_METADATA = 0;
 Entry.READY_TO_PUMP_FILE_DATA = 1;
@@ -565,7 +567,7 @@ Entry.prototype.getCentralDirectoryRecord = function() {
   // extra field length              2 bytes
   fixedSizeStuff.writeUInt16LE(zeiefBuffer.length, 30);
   // file comment length             2 bytes
-  fixedSizeStuff.writeUInt16LE(0, 32);
+  fixedSizeStuff.writeUInt16LE(this.fileComment.length, 32);
   // disk number start               2 bytes
   fixedSizeStuff.writeUInt16LE(0, 34);
   // internal file attributes        2 bytes
@@ -582,7 +584,7 @@ Entry.prototype.getCentralDirectoryRecord = function() {
     // extra field (variable size)
     zeiefBuffer,
     // file comment (variable size)
-    // empty comment
+    this.fileComment
   ]);
 };
 Entry.prototype.getCompressionMethod = function() {
@@ -606,7 +608,7 @@ function dateToDosDateTime(jsDate) {
 }
 
 function writeUInt64LE(buffer, n, offset) {
-  // can't use bitshift here, because JavaScript only allows bitshiting on 32-bit integers.
+  // can't use bitshift here, because JavaScript only allows bitshifting on 32-bit integers.
   var high = Math.floor(n / 0x100000000);
   var low = n % 0x100000000;
   buffer.writeUInt32LE(low, offset);

test/test.js

@@ -126,3 +126,51 @@ var BufferList = require("bl");
     }));
   });
 })();
+
+(function() {
+  var zipfile = new yazl.ZipFile();
+  var comment = "Hello World";
+  zipfile.end({
+    comment: comment
+  }, function(finalSize) {
+    if (finalSize === -1) throw new Error("finalSize should be known");
+    zipfile.outputStream.pipe(new BufferList(function(err, data) {
+      if (err) throw err;
+      if (data.length !== finalSize) throw new Error("finalSize prediction is wrong. " + finalSize + " !== " + data.length);
+      yauzl.fromBuffer(data, function(err, zipfile) {
+        if (err) throw err;
+        if (zipfile.comment !== comment) {
+          throw new Error("fileComment didn't match: " + zipfile.fileComment + ", expected: " + fileComment);
+        }
+        console.log("comment: pass");
+      });
+    }));
+  });
+})();
+
+(function() {
+  var fileComment = "Hello World";
+  var zipfile = new yazl.ZipFile();
+  // all options parameters are optional
+  zipfile.addBuffer(Buffer.from("hello"), "hello.txt", {compress: false, fileComment: fileComment});
+  zipfile.end(function(finalSize) {
+    if (finalSize === -1) throw new Error("finalSize should be known");
+    zipfile.outputStream.pipe(new BufferList(function(err, data) {
+      if (err) throw err;
+      if (data.length !== finalSize) throw new Error("finalSize prediction is wrong. " + finalSize + " !== " + data.length);
+      yauzl.fromBuffer(data, function(err, zipfile) {
+        if (err) throw err;
+        var entryNames = ["hello.txt"];
+        zipfile.on("entry", function(entry) {
+          var expectedName = entryNames.shift();
+          if (entry.fileComment !== fileComment) {
+            throw new Error("unexpected entry fileComment: " + entry.fileComment + ", expected: " + fileComment);
+          }
+        });
+        zipfile.on("end", function() {
+          if (entryNames.length === 0) console.log("fileComment: pass");
+        });
+      });
+    }));
+  });
+})();