regression test - write method does not wait to complete writing #2903

Author: liborm85

tests/unit/Node-interface.spec.js

@@ -1,5 +1,10 @@
 'use strict';
 
+var assert = require('assert');
+var fs = require('fs/promises');
+var path = require('path');
+var os = require('os');
+
 var pdfmake = require('../../js/index');
 
 pdfmake.addFonts({
@@ -32,4 +37,28 @@ describe('Node interface', function () {
 		});
 
 	});
+
+	describe('write', function () {
+		it('should write file', async function () {
+
+			var docDefinition = {
+				content: [
+					'First paragraph',
+					'Another paragraph, this time a little bit longer to make sure, this line will be divided into at least two lines'
+				]
+			};
+
+			const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'pdfmake-'));
+			const pdfFilename = path.join(tmpDir, 'document.pdf');
+
+			var pdf = pdfmake.createPdf(docDefinition);
+			await pdf.write(pdfFilename);
+
+			const stats = await fs.stat(pdfFilename);
+			assert.ok(stats.size > 0);
+
+			await fs.rm(tmpDir, { recursive: true, force: true });
+		});
+
+	});
 });