💡 Improve comments and code quality

src/ssn/extractFile.ts

@@ -7,29 +7,33 @@ import ByteReader from './extractFileByteReader';
  * Will throw an error when end of final DataView is reached.
  */
 export default async function extractFile(file: ISsnFileEntry, dvArray: DataView[]): Promise<ArrayBuffer> {
-  //use ByteReader for reading a uint8 and seeking forward across DataView boundaries
+  //Use ByteReader for reading a uint8 and seeking forward across DataView boundaries
   const byteReader = new ByteReader(dvArray, file.diskNumberStart, file.offset);
 
+  //Local file header signature must be 0x04034B50
   if (byteReader.readByte() !== 0x50 || byteReader.readByte() !== 0x4B || byteReader.readByte() !== 0x03 || byteReader.readByte() !== 0x04) {
-        throw new Error('Local file header had wrong magic');
+    throw new Error('Local file header had wrong magic');
   }
+  //All fields in the local file header are copies of the central file header, so we can skip them.
+  //FIXME: Maybe we should actually read these fields to verify that they are identical?
   byteReader.seek(22);
   const localFilenameSize = byteReader.readByte() + (byteReader.readByte() << 8);
   const localExtraSize = byteReader.readByte() + (byteReader.readByte() << 8);
   byteReader.seek(localFilenameSize + localExtraSize);
 
+  //Extract actual file contents
   let dvFinal = byteReader.extractDv(file.comprSize);
 
-  //decrypt file if necessary
+  //Decrypt file if necessary
   if (file.decryptionKeys !== undefined) {
     dvFinal = decryptFile(dvFinal, file.comprSize, file.decryptionKeys);
   }
 
-  //uncompress file
+  //Uncompress file
   const uncompressedBuffer: Buffer = await new Promise((resolve, reject) => {
     zlib.inflateRaw(dvFinal, (error, result) => {
       if (error !== null) {
-        reject(error);
+        return reject(error);
       }
       resolve(result);
     });

src/ssn/getPatch.ts

@@ -7,13 +7,14 @@ import readSsnFile from './readSsnFile';
 
 export default async function getPatch(product: Product, from: number, to: number) {
   const solidPkg = await getSolidpkg(product, from, to);
-  console.log(solidPkg.files);
+  console.debug(solidPkg.files);
 
   const bufferArray = await Promise.all(solidPkg.files.map((file) => getUrlContents({ host: 'cdn-patch.swtor.com', path: `/patch/${product}/${product}_${from}to${to}/${file.name}` })));
   const zipFile = bufferArray[bufferArray.length - 1];
   const dvArray = bufferArray.map((buffer) => new DataView(buffer));
 
   const fileEntries = readSsnFile(zipFile);
+  console.debug(fileEntries);
 
   //Verify file entries
   if (from === -1) {
@@ -22,19 +23,18 @@ export default async function getPatch(product: Product, from: number, to: numbe
     });
   }
   //TODO: last file must always be `${product}.version` with diff type. Other files depend on diffType.
-  console.log(fileEntries);
 
   //Extract newly added files
   fileEntries.filter((file) => file.diffType === SsnDiffType.NewFile).forEach(async (file) => {
     const fileContents = await extractFile(file, dvArray);
-    console.log(fileContents);
+    console.debug(fileContents);
     //TODO
   });
 
   //Extract changed files
   fileEntries.filter((file) => file.diffType === SsnDiffType.Changed).forEach(async (file) => {
     const fileContents = await extractFile(file, dvArray);
-    console.log(fileContents);
+    console.debug(fileContents);
     //TODO
   });