updated .load, .loadRoot, rootTemplate and preTemplates to allow for supplying buffers in addition to file paths.

Author: mikemeerschaert

__tests__/create-presentation-from-buffer.test.ts

@@ -0,0 +1,23 @@
+import fs from 'fs/promises';
+import Automizer from '../src/automizer';
+
+test('create presentation from buffer and add basic slide', async () => {
+  const automizer = new Automizer({
+    outputDir: `${__dirname}/pptx-output`,
+  });
+  const rootTemplate = await fs.readFile(
+    `${__dirname}/pptx-templates/RootTemplate.pptx`,
+  );
+  const slideWithShapes = await fs.readFile(
+    `${__dirname}/pptx-templates/SlideWithShapes.pptx`,
+  );
+  const pres = automizer.loadRoot(rootTemplate).load(slideWithShapes, 'shapes');
+
+  for (let i = 0; i <= 10; i++) {
+    pres.addSlide('shapes', 1);
+  }
+
+  await pres.write(`create-presentation-from-buffer.test.pptx`);
+
+  expect(pres).toBeInstanceOf(Automizer);
+});