feat: added proper tests

Author: aryanjassal

package-lock.json

@@ -41,6 +41,7 @@
     "uuid": "^11.0.5"
   },
   "devDependencies": {
+    "@fast-check/jest": "^1.1.0",
     "@swc/core": "^1.3.62",
     "@swc/jest": "^0.2.26",
     "@types/jest": "^28.1.3",
@@ -51,6 +52,7 @@
     "eslint-config-prettier": "^8.5.0",
     "eslint-plugin-import": "^2.26.0",
     "eslint-plugin-prettier": "^4.0.0",
+    "fast-check": "^3.0.1",
     "jest": "^28.1.1",
     "jest-extended": "^3.0.1",
     "jest-junit": "^14.0.0",

package.json

@@ -6,18 +6,13 @@ import * as constants from './constants';
 
 // Computes the checksum by summing up all the bytes in the header
 function computeChecksum(header: Uint8Array): number {
-  if (!header.slice(148, 156).every((byte) => byte === 32)) {
-    throw new errors.ErrorVirtualTarInvalidHeader(
-      'Checksum field is not properly initialized with spaces',
-    );
-  }
   return header.reduce((sum, byte) => sum + byte, 0);
 }
 
-function createHeader(
+function generateHeader(
   filePath: string,
-  stat: FileStat,
   type: EntryType,
+  stat: FileStat,
 ): Uint8Array {
   // TODO: implement long-file-name headers
   if (filePath.length < 1 || filePath.length > 255) {
@@ -26,14 +21,6 @@ function createHeader(
     );
   }
 
-  // The file path must not contain any directories, and must only contain a
-  // file name. This guard checks that.
-  if (filePath.includes('/')) {
-    throw new errors.ErrorVirtualTarInvalidFileName(
-      'File name must not contain /',
-    );
-  }
-
   // As the size does not matter for directories, it can be undefined. However,
   // if the header is being generated for a file, then it needs to have a valid
   // size. This guard checks that.
@@ -202,14 +189,11 @@ function createHeader(
   return header;
 }
 
-// Creates blocks marking the ned of the header. Returns one buffer of 1024
-// bytes filled with nulls. This aligns with the tar end-of-archive marker
-// being two null-filled blocks.
-function generateEndMarker() {
-  return [
-    new Uint8Array(constants.BLOCK_SIZE),
-    new Uint8Array(constants.BLOCK_SIZE),
-  ];
+// Creates a single null block. A null block is a block filled with all zeros.
+// This is needed to end the archive, as two of these blocks mark the end of
+// archive.
+function generateNullChunk() {
+  return new Uint8Array(constants.BLOCK_SIZE);
 }
 
-export { createHeader, generateEndMarker };
+export { generateHeader, generateNullChunk };