feat: add file validation utilities

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

test/file.test.js

@@ -0,0 +1,88 @@
+import { describe, it, expect } from "bun:test";
+import { getFileType, checkFileSize, extractFileName, extractMimeType } from "../src/utils/file.js";
+
+describe("File Utilities", () => {
+  describe("getFileType", () => {
+    it("should classify video mime types as video", () => {
+      expect(getFileType("video/mp4", "")).toBe("video");
+      expect(getFileType("video/quicktime", "")).toBe("video");
+    });
+
+    it("should classify audio mime types as audio", () => {
+      expect(getFileType("audio/mpeg", "")).toBe("audio");
+      expect(getFileType("audio/ogg", "")).toBe("audio");
+    });
+
+    it("should classify image mime types based on caption", () => {
+      expect(getFileType("image/jpeg", "my photo")).toBe("photo");
+      expect(getFileType("image/png", "cool image.png")).toBe("photo");
+      expect(getFileType("image/gif", "funny.gif")).toBe("animation");
+      expect(getFileType("image/png", "funny gif")).toBe("animation");
+    });
+
+    it("should classify voice and animation based on caption", () => {
+      expect(getFileType("application/octet-stream", "this is a voice note")).toBe("voice");
+      expect(getFileType("application/octet-stream", "cool animation")).toBe("animation");
+    });
+
+    it("should default to mime first segment or document", () => {
+      expect(getFileType("application/pdf", "")).toBe("application");
+      expect(getFileType(null, "")).toBe("document");
+    });
+  });
+
+  describe("checkFileSize", () => {
+    it("should allow files under the size limit", () => {
+      expect(checkFileSize(5 * 1024 * 1024, "photo")).toBe(true); // Photo limit is 10MB
+      expect(checkFileSize(1 * 1024 * 1024 * 1024, "video")).toBe(true); // Video limit is 2GB
+    });
+
+    it("should block files exceeding the size limit", () => {
+      expect(checkFileSize(15 * 1024 * 1024, "photo")).toBe(false); // Photo limit is 10MB
+      expect(checkFileSize(3 * 1024 * 1024 * 1024, "video")).toBe(false); // Video limit is 2GB
+    });
+
+    it("should fall back to document limit if fileType is unknown", () => {
+      expect(checkFileSize(1 * 1024 * 1024 * 1024, "unknown")).toBe(true); // Document limit is 2GB
+      expect(checkFileSize(3 * 1024 * 1024 * 1024, "unknown")).toBe(false);
+    });
+  });
+
+  describe("extractFileName", () => {
+    it("should extract file name from headers if present", () => {
+      const req = { headers: { "x-file-name": "custom.txt" } };
+      expect(extractFileName({}, req)).toBe("custom.txt");
+    });
+
+    it("should extract file name from various message attachment types", () => {
+      expect(extractFileName({ document: { fileName: "doc.pdf" } }, null)).toBe("doc.pdf");
+      expect(extractFileName({ photo: [{ fileName: "low.jpg" }, { fileName: "high.jpg" }] }, null)).toBe("high.jpg");
+      expect(extractFileName({ audio: { fileName: "song.mp3" } }, null)).toBe("song.mp3");
+      expect(extractFileName({ voice: { fileName: "voice.ogg" } }, null)).toBe("voice.ogg");
+      expect(extractFileName({ animation: { fileName: "anim.gif" } }, null)).toBe("anim.gif");
+    });
+
+    it("should return default filename if not found", () => {
+      expect(extractFileName({}, null)).toBe("file");
+    });
+  });
+
+  describe("extractMimeType", () => {
+    it("should extract mime type from headers if present", () => {
+      const req = { headers: { "x-mime-type": "text/plain" } };
+      expect(extractMimeType({}, req)).toBe("text/plain");
+    });
+
+    it("should extract mime type from various message attachment types", () => {
+      expect(extractMimeType({ document: { mimeType: "application/pdf" } }, null)).toBe("application/pdf");
+      expect(extractMimeType({ photo: [{ mimeType: "image/jpeg" }, { mimeType: "image/png" }] }, null)).toBe("image/png");
+      expect(extractMimeType({ audio: { mimeType: "audio/mpeg" } }, null)).toBe("audio/mpeg");
+      expect(extractMimeType({ voice: { mimeType: "audio/ogg" } }, null)).toBe("audio/ogg");
+      expect(extractMimeType({ animation: { mimeType: "video/mp4" } }, null)).toBe("video/mp4");
+    });
+
+    it("should return default mime type if not found", () => {
+      expect(extractMimeType({}, null)).toBe("application/octet-stream");
+    });
+  });
+});