💡 Add comments

src/config.ts

@@ -17,7 +17,7 @@ export const set = (key: string, value: any) => {
       if (typeof value !== 'number') { throw new Error(`release must be a number but it's a "${typeof value}".`); }
       if ((value | 0) !== value) { throw new Error(`release must be an integer but it's ${value}.`); }
       if (value < 0) { throw new Error(`release must be a non-negative integer but it's ${value}.`); }
-      if (settings.from !== undefined && value <= settings.from ) { throw new Error(`release must be bigger than from but ${value} is not bigger than ${settings.from}.`); }
+      if (settings.from !== undefined && value <= settings.from ) { throw new Error(`release must be greater than from but ${value} is not greater than ${settings.from}.`); }
       settings.release = value;
       break;
     case 'from':
@@ -25,7 +25,7 @@ export const set = (key: string, value: any) => {
       if (typeof value !== 'number') { throw new Error(`from must be a number but it's a "${typeof value}".`); }
       if ((value | 0) !== value) { throw new Error(`from must be an integer but it's ${value}.`); }
       if (value < -1) { throw new Error(`from must be a non-negative integer or -1, but it's ${value}.`); }
-      if (settings.release !== undefined && value >= settings.release ) { throw new Error(`from must be smaller than release but ${value} is not smaller than ${settings.release}.`); }
+      if (settings.release !== undefined && value >= settings.release ) { throw new Error(`from must be less than release but ${value} is not less than ${settings.release}.`); }
       settings.from = value;
       break;
     case 'outputType':

src/ssn/getSolidpkg.ts

@@ -9,13 +9,13 @@ export default function getSolidpkg(product: Product, from: number, to: number):
   }
 
   if (typeof from !== 'number' || (from | 0) !== from || from < -1) {
-    throw new Error(`from must be an integer at least -1 but it is "${from}"`);
+    throw new Error(`from must be an integer greater than or equal to -1 but it is "${from}"`);
   }
   if (typeof to !== 'number' || (to | 0) !== to || to < 0) {
-    throw new Error(`to must be an integer at least 0 but it is "${to}"`);
+    throw new Error(`to must be an integer greater than or equal to 0 but it is "${to}"`);
   }
   if (from >= to) {
-    throw new Error(`from must be smaller than to but "${from}" is not smaller than "${to}".`);
+    throw new Error(`from must be less than to but "${from}" is not less than "${to}".`);
   }
 
   return getUrlContents({ host: 'cdn-patch.swtor.com', path: `/patch/${product}/${product}_${from}to${to}.solidpkg` });

src/ssn/readSolidpkg.ts

@@ -1,3 +1,8 @@
+/**
+ * The file format used by Solid State Networks is based on the .zip format.
+ * Check the .ZIP File Format Specification <https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT>.
+ */
+
 import { TextDecoder } from 'util';
 import modifyPassword from './modifyPassword';
 
@@ -50,7 +55,7 @@ export default function readSolidpkg(buffer: Buffer) {
     throw new Error(`Central dir points before file start (0x${(pos - centralDirSize).toString(16)})`);
   }
 
-  //--------------- READ CENTRAL DIR ---------------
+  //--------------- READ CENTRAL DIRECTORY ---------------
 
   //Go to start of central dir
   pos -= 20 + centralDirSize;
@@ -62,31 +67,41 @@ export default function readSolidpkg(buffer: Buffer) {
     }
   }
 
-  pos += 4; //skip version
+  pos += 4; //skip version made by and version needed to extract
 
-  /** The bitflag stores whether the file is encrypted or not. Most files are encrypted but there are
+  /** The general purpose bit flag stores whether the file is encrypted or not.
-   * some exceptions: assets_swtor_test_main_248to249.solidpkg, assets_swtor_test_en_us_270to271.solidpkg, and
+   * Most files are encrypted but there are some exceptions: assets_swtor_test_main_248to249.solidpkg,
-   * retailclient_publictest_246to247.solidpkg are not encrypted.
+   * assets_swtor_test_en_us_270to271.solidpkg, and retailclient_publictest_246to247.solidpkg are not encrypted.
    */
   const bitFlag = dv.getUint16(pos, true); pos += 2;
 
-  /** Type of compression, 8 = DEFLATE. Files are always compressed. */
+  /** Compression method, always set to 8 = DEFLATE. */
   const compression = dv.getUint16(pos, true); pos += 2;
   if (compression !== COMPRESSION_DEFLATE) {
     throw new Error(`File is not using DEFLATE compression but "${compression}"`);
   }
 
+  /** last mod file time */
   const lastMod1 = dv.getUint16(pos, true); pos += 2;
+  /** last mod file date */
   const lastMod2 = dv.getUint16(pos, true); pos += 2;
+  /** crc-32 */
   const fileCrc = dv.getUint32(pos, true); pos += 4;
+  /** compressed size */
   const comprSize = dv.getUint32(pos, true); pos += 4;
+  /** uncompressed size */
   const uncomprSize = dv.getUint32(pos, true); pos += 4;
+  /** file name length */
   const fileNameLength = dv.getUint16(pos, true); pos += 2;
+  /** extra field length */
   const extraFieldLength = dv.getUint16(pos, true); pos += 2;
+  /** file comment length */
   const fileCommentLength = dv.getUint16(pos, true); pos += 2;
-  pos += 8; //skip disk num start and file attributes
+  pos += 8; //skip disk number start, internal file attributes and external file attributes
+  /** relative offset of local header */
   const relOffset = dv.getUint32(pos, true); pos += 4;
-  const fileName = Decoder.decode(new DataView(arrayBuffer, pos, fileNameLength)); pos += fileNameLength; //skip file name
+  /** file name (variable size) */
+  const fileName = Decoder.decode(new DataView(arrayBuffer, pos, fileNameLength)); pos += fileNameLength;
   if (fileName !== 'metafile.solid') {
     throw new Error(`Expected file name to be "metafile.solid" but it was "${fileName}".`);
   }
@@ -100,7 +115,7 @@ export default function readSolidpkg(buffer: Buffer) {
     switch (fieldId) {
       case 0x8810: { //password
         if (fieldLength > 120) {
-          throw new Error(`Password is too long, it should be 120 characters at most but is ${fieldLength} characters long.`);
+          throw new Error(`Password is too long, it should be 120 characters at most but it is ${fieldLength} characters long.`);
         }
         const passwordLength = fieldLength;
         encodedPassword = new Uint8Array(arrayBuffer, pos, fieldLength);