MAESTRO: add file drop e2e coverage

frontend/e2e/file-drop.spec.ts

@@ -0,0 +1,60 @@
+import { test, expect } from "@playwright/test";
+import fs from "fs/promises";
+import path from "path";
+
+import { AnalyzerPage } from "./pages/analyzer-page";
+
+const emlPath = path.resolve(__dirname, "fixtures/sample.eml");
+
+const extractHeaderBlock = (content: string): string => {
+  const normalized = content.replace(/\r\n/g, "\n").replace(/\r/g, "\n");
+  const lines = normalized.split("\n");
+  const headerLines: string[] = [];
+
+  for (const line of lines) {
+    if (line.trim() === "") {
+      break;
+    }
+    headerLines.push(line);
+  }
+
+  if (headerLines.length === 0) {
+    return normalized.trim();
+  }
+
+  return headerLines.join("\n").trimEnd();
+};
+
+test("drop eml file populates headers and renders report", async ({ page }) => {
+  const analyzer = new AnalyzerPage(page);
+  const emlContents = await fs.readFile(emlPath, "utf8");
+  const expectedHeaders = extractHeaderBlock(emlContents);
+
+  await analyzer.goto();
+  await analyzer.dropFile(emlPath);
+
+  const headerInput = page.getByRole("textbox", { name: "Header Input" });
+  await expect(headerInput).toHaveValue(expectedHeaders);
+
+  await analyzer.clickAnalyse();
+  await analyzer.waitForResults();
+
+  await expect(analyzer.getResultCards().first()).toBeVisible();
+});
+
+test("rejects unsupported file types", async ({ page }, testInfo) => {
+  const analyzer = new AnalyzerPage(page);
+  const invalidPath = testInfo.outputPath("unsupported.pdf");
+  await fs.writeFile(invalidPath, "%PDF-1.4 fake pdf content");
+
+  await analyzer.goto();
+  await analyzer.dropFile(invalidPath, "application/pdf");
+
+  const alert = page
+    .locator('p[role="alert"]')
+    .filter({ hasText: "Only .eml or .txt files are supported." });
+  await expect(alert).toBeVisible();
+
+  const headerInput = page.getByRole("textbox", { name: "Header Input" });
+  await expect(headerInput).toHaveValue("");
+});