refactor: Restructure source code folder

This way the location of certain classes should make more sense

test/unit/http/output/metadata/ModifiedMetadataWriter.test.ts

@@ -0,0 +1,29 @@
+import { createResponse } from 'node-mocks-http';
+import { ModifiedMetadataWriter } from '../../../../../src/http/output/metadata/ModifiedMetadataWriter';
+import { RepresentationMetadata } from '../../../../../src/http/representation/RepresentationMetadata';
+import type { HttpResponse } from '../../../../../src/server/HttpResponse';
+import { updateModifiedDate } from '../../../../../src/util/ResourceUtil';
+import { DC } from '../../../../../src/util/Vocabularies';
+
+describe('A ModifiedMetadataWriter', (): void => {
+  const writer = new ModifiedMetadataWriter();
+
+  it('adds the Last-Modified and ETag header if there is dc:modified metadata.', async(): Promise<void> => {
+    const response = createResponse() as HttpResponse;
+    const metadata = new RepresentationMetadata();
+    updateModifiedDate(metadata);
+    const dateTime = metadata.get(DC.terms.modified)!.value;
+    await expect(writer.handle({ response, metadata })).resolves.toBeUndefined();
+    expect(response.getHeaders()).toEqual({
+      'last-modified': new Date(dateTime).toUTCString(),
+      etag: `"${new Date(dateTime).getTime()}"`,
+    });
+  });
+
+  it('does nothing if there is no matching metadata.', async(): Promise<void> => {
+    const response = createResponse() as HttpResponse;
+    const metadata = new RepresentationMetadata();
+    await expect(writer.handle({ response, metadata })).resolves.toBeUndefined();
+    expect(response.getHeaders()).toEqual({});
+  });
+});