Fix compress after previous refactor and add a unit test.

tests/compress.spec.js

@@ -0,0 +1,59 @@
+import * as fs from 'node:fs';
+import 'mocha';
+import { expect } from 'chai';
+import { Unarchiver, getUnarchiver } from '../archive/decompress.js';
+import { CompressStatus, Zipper, ZipCompressionMethod } from '../archive/compress.js';
+
+/**
+ * @typedef {import('./archive/compress.js').FileInfo} FileInfo
+ */
+
+const PATH = `tests/archive-testfiles/`;
+
+const INPUT_FILENAMES = [
+  'sample-1.txt',
+  'sample-2.csv',
+  'sample-3.json',
+];
+
+describe('bitjs.archive.compress', () => {
+  /** @type {Map<string, FileInfo>} */
+  let inputFileInfos = new Map();
+  let decompressedFileSize = 0;
+
+  before(() => {
+    for (const fileName of INPUT_FILENAMES) {
+      const fullFilename = `${PATH}${fileName}`;
+      const fd = fs.openSync(fullFilename, 'r');
+      const lastModTime = fs.fstatSync(fd).mtimeMs;
+      const nodeBuf = fs.readFileSync(fullFilename);
+      const fileData = new Uint8Array(
+          nodeBuf.buffer.slice(nodeBuf.byteOffset, nodeBuf.byteOffset + nodeBuf.length));
+      inputFileInfos.set(fileName, {fileName, lastModTime, fileData});
+      decompressedFileSize += fileData.byteLength;
+      fs.closeSync(fd);
+    }
+  });
+
+  it('zipper works', (done) => {
+    const files = new Map(inputFileInfos);
+    const zipper = new Zipper({zipCompressionMethod: ZipCompressionMethod.STORE});
+    zipper.start(Array.from(files.values()), true).then(byteArray => {
+      expect(zipper.compressState).equals(CompressStatus.COMPLETE);
+      expect(byteArray.byteLength > decompressedFileSize).equals(true);
+
+      const unarchiver = getUnarchiver(byteArray.buffer);
+      unarchiver.addEventListener('extract', evt => {
+        const {filename, fileData} = evt.unarchivedFile;
+        expect(files.has(filename)).equals(true);
+        const inputFile = files.get(filename).fileData;
+        expect(inputFile.byteLength).equals(fileData.byteLength);
+        for (let b = 0; b < inputFile.byteLength; ++b) {
+          expect(inputFile[b]).equals(fileData[b]);
+        }
+      });
+      unarchiver.addEventListener('finish', evt => done());
+      unarchiver.start();
+    });
+  });
+});