added e2e test

ghost/core/test/e2e-frontend/static-files.test.js

@@ -0,0 +1,25 @@
+const assert = require('assert/strict');
+const {agentProvider} = require('../utils/e2e-framework');
+
+describe('Static files', function () {
+    let frontendAgent;
+    let ghostServer;
+
+    before(async function () {
+        const agents = await agentProvider.getAgentsWithFrontend();
+        frontendAgent = agents.frontendAgent;
+        ghostServer = agents.ghostServer;
+    });
+
+    after(async function () {
+        await ghostServer.stop();
+    });
+
+    it('serves unstyled 404 for non-existing resized + original files', async function () {
+        const response = await frontendAgent
+            .get('/content/images/size/w2000/1995/12/daniel.jpg')
+            .expect(404);
+
+        assert.ok(response.text.includes('NotFoundError: Image not found'));
+    });
+});