Add a helper method to compress file hierarchies based on glob pattern

lib/zip.js

@@ -177,5 +177,52 @@ async function assertValidZip (filePath) {
   }
 }
 
-export { extractAllTo, readEntries, toInMemoryZip, _extractEntryTo, assertValidZip };
-export default { extractAllTo, readEntries, toInMemoryZip, assertValidZip };
+/**
+ * @typedef {Object} ZipCompressionOptions
+ * @property {number} level [9] - Compression level in range 0..9
+ * (greater numbers mean better compression, but longer processing time)
+ */
+
+/**
+ * @typedef {Object} ZipSourceOptions
+ * @property {!string} pattern ['**\/*'] - GLOB pattern for compression
+ * @property {!string} cwd - The source root folder (the parent folder of
+ * the destination file by default)
+ * @property {?Array<string>} ignore - The list of ignored patterns
+ */
+
+/**
+ * Creates an archive based on the given glob pattern
+ *
+ * @param {string} dstPath - The resulting archive path
+ * @param {ZipSourceOptions} src - Source options
+ * @param {ZipCompressionOptions} opts - Compression options
+ * @throws {Error} If there was an error while creating the archive
+ */
+async function toArchive (dstPath, src = {}, opts = {}) {
+  const {
+    level = 9,
+  } = opts;
+  const {
+    pattern = '**/*',
+    cwd = path.dirname(dstPath),
+    ignore = [],
+  } = src;
+  const archive = archiver('zip', { zlib: { level }});
+  const stream = fs.createWriteStream(dstPath);
+  return await new B((resolve, reject) => {
+    archive
+      .glob(pattern, {
+        cwd,
+        ignore,
+      })
+      .on('error', reject)
+      .pipe(stream);
+    stream.on('close', resolve);
+    archive.finalize();
+  });
+}
+
+export { extractAllTo, readEntries, toInMemoryZip, _extractEntryTo,
+  assertValidZip, toArchive };
+export default { extractAllTo, readEntries, toInMemoryZip, assertValidZip, toArchive };

test/zip-e2e-specs.js

@@ -149,4 +149,23 @@ describe('#zip', function () {
     });
   });
 
+  describe('toArchive', function () {
+    it('should zip all files into an archive', async function () {
+      const testFolder = path.resolve(assetsPath, 'unzipped');
+      const dstPath = path.resolve(tmpRoot, 'test.zip');
+      await zip.toArchive(dstPath, {
+        cwd: testFolder,
+      });
+
+      // Unzip the file and test that it has the same contents as the directory that was zipped
+      await zip.extractAllTo(dstPath, path.resolve(tmpRoot, 'output'));
+      await fs.readFile(path.resolve(tmpRoot, 'output', 'test-dir', 'a.txt'), {
+        encoding: 'utf8'
+      }).should.eventually.equal('Hello World');
+      await fs.readFile(path.resolve(tmpRoot, 'output', 'test-dir', 'b.txt'), {
+        encoding: 'utf8'
+      }).should.eventually.equal('Foo Bar');
+    });
+  });
+
 });