fix(gzip): Improve gzip streaming decompression, archive analysis and unpacking; add gzip tests

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartarchive',
-  version: '4.2.0',
+  version: '4.2.1',
   description: 'A library for working with archive files, providing utilities for compressing and decompressing data.'
 }

ts/classes.gziptools.ts

@@ -26,8 +26,20 @@ export class CompressGunzipTransform extends plugins.stream.Transform {
 // DecompressGunzipTransform class that extends the Node.js Transform stream to
 // create a stream that decompresses GZip-compressed data using fflate's gunzip function
 export class DecompressGunzipTransform extends plugins.stream.Transform {
+  private gunzip: any; // fflate.Gunzip instance
+  
   constructor() {
     super();
+    
+    // Create a streaming Gunzip decompressor
+    this.gunzip = new plugins.fflate.Gunzip((chunk, final) => {
+      // Push decompressed chunks to the output stream
+      this.push(Buffer.from(chunk));
+      if (final) {
+        // Signal end of stream when decompression is complete
+        this.push(null);
+      }
+    });
   }
 
   _transform(
@@ -35,17 +47,23 @@ export class DecompressGunzipTransform extends plugins.stream.Transform {
     encoding: BufferEncoding,
     callback: plugins.stream.TransformCallback,
   ) {
-    // Use fflate's gunzip function to decompress the chunk
-    plugins.fflate.gunzip(chunk, (err, decompressed) => {
-      if (err) {
-        // If an error occurs during decompression, pass the error to the callback
-        callback(err);
-      } else {
-        // If decompression is successful, push the decompressed data into the stream
-        this.push(decompressed);
-        callback();
-      }
-    });
+    try {
+      // Feed chunks to the gunzip stream
+      this.gunzip.push(chunk, false);
+      callback();
+    } catch (err) {
+      callback(err as Error);
+    }
+  }
+  
+  _flush(callback: plugins.stream.TransformCallback) {
+    try {
+      // Signal end of input to gunzip
+      this.gunzip.push(new Uint8Array(0), true);
+      callback();
+    } catch (err) {
+      callback(err as Error);
+    }
   }
 }