1 files changed, 136 insertions, 0 deletions
diff --git a/packages/core/tests/models/attachments.test.ts b/packages/core/tests/models/attachments.test.ts
new file mode 100644
index 0000000..11a9f82
--- /dev/null
+++ b/packages/core/tests/models/attachments.test.ts
@@ -0,0 +1,136 @@
+import { describe, expect, it } from "vitest";
+import {
+	base64ByteLength,
+	isAcceptedAttachmentMediaType,
+	isImageMediaType,
+	isPdfMediaType,
+	MAX_ATTACHMENTS,
+	MAX_IMAGE_BYTES,
+	MAX_PDF_BYTES,
+	MAX_TOTAL_ATTACHMENT_BYTES,
+	validateUserContent,
+} from "../../src/models/attachments.js";
+import type { UserContentPart } from "../../src/types/index.js";
+
+/** A base64 string that decodes to exactly `bytes` bytes (no padding chars). */
+function base64OfBytes(bytes: number): string {
+	// 4 base64 chars → 3 bytes. Use a multiple of 3 for clean (unpadded) output.
+	const groups = Math.ceil(bytes / 3);
+	return "A".repeat(groups * 4);
+}
+
+function imagePart(data: string, mediaType = "image/png"): UserContentPart {
+	return { type: "attachment", mediaType, data };
+}
+
+describe("media-type predicates", () => {
+	it("classifies image types", () => {
+		expect(isImageMediaType("image/png")).toBe(true);
+		expect(isImageMediaType("image/jpeg")).toBe(true);
+		expect(isImageMediaType("image/webp")).toBe(true);
+		expect(isImageMediaType("image/gif")).toBe(true);
+		expect(isImageMediaType("application/pdf")).toBe(false);
+		expect(isImageMediaType("image/svg+xml")).toBe(false);
+	});
+
+	it("classifies pdf + accepted types", () => {
+		expect(isPdfMediaType("application/pdf")).toBe(true);
+		expect(isPdfMediaType("image/png")).toBe(false);
+		expect(isAcceptedAttachmentMediaType("image/gif")).toBe(true);
+		expect(isAcceptedAttachmentMediaType("application/pdf")).toBe(true);
+		expect(isAcceptedAttachmentMediaType("text/plain")).toBe(false);
+	});
+});
+
+describe("base64ByteLength", () => {
+	it("computes decoded length without padding", () => {
+		// "AAAA" → 3 bytes.
+		expect(base64ByteLength("AAAA")).toBe(3);
+	});
+
+	it("accounts for padding", () => {
+		// "QQ==" → 1 byte ("A").
+		expect(base64ByteLength("QQ==")).toBe(1);
+		// "QUI=" → 2 bytes ("AB").
+		expect(base64ByteLength("QUI=")).toBe(2);
+	});
+
+	it("tolerates a data: URI prefix and whitespace", () => {
+		expect(base64ByteLength("data:image/png;base64,AAAA")).toBe(3);
+		expect(base64ByteLength("AA\nAA")).toBe(3);
+	});
+
+	it("returns 0 for empty input", () => {
+		expect(base64ByteLength("")).toBe(0);
+		expect(base64ByteLength("   ")).toBe(0);
+	});
+});
+
+describe("validateUserContent", () => {
+	it("accepts a small image and ignores text parts", () => {
+		const content: UserContentPart[] = [
+			{ type: "text", text: "hi" },
+			imagePart(base64OfBytes(1024)),
+		];
+		expect(validateUserContent(content)).toEqual({ ok: true, errors: [] });
+	});
+
+	it("accepts an empty / text-only content list", () => {
+		expect(validateUserContent([]).ok).toBe(true);
+		expect(validateUserContent([{ type: "text", text: "no files" }]).ok).toBe(true);
+	});
+
+	it("rejects an unsupported media type", () => {
+		const res = validateUserContent([imagePart(base64OfBytes(10), "image/svg+xml")]);
+		expect(res.ok).toBe(false);
+		expect(res.errors[0]).toMatchObject({ code: "unsupported-type", mediaType: "image/svg+xml" });
+	});
+
+	it("rejects an oversized image but allows a PDF of the same size", () => {
+		const big = base64OfBytes(MAX_IMAGE_BYTES + 3);
+		const imgRes = validateUserContent([imagePart(big, "image/png")]);
+		expect(imgRes.ok).toBe(false);
+		expect(imgRes.errors.some((e) => e.code === "image-too-large")).toBe(true);
+
+		// Same byte size as a PDF is fine (PDF limit is much higher).
+		const pdfRes = validateUserContent([imagePart(big, "application/pdf")]);
+		expect(pdfRes.ok).toBe(true);
+	});
+
+	it("rejects an oversized PDF", () => {
+		const res = validateUserContent([
+			imagePart(base64OfBytes(MAX_PDF_BYTES + 3), "application/pdf"),
+		]);
+		expect(res.ok).toBe(false);
+		expect(res.errors.some((e) => e.code === "pdf-too-large")).toBe(true);
+	});
+
+	it("rejects an empty attachment payload", () => {
+		const res = validateUserContent([imagePart("", "image/png")]);
+		expect(res.ok).toBe(false);
+		expect(res.errors.some((e) => e.code === "empty")).toBe(true);
+	});
+
+	it("rejects too many attachments", () => {
+		const content: UserContentPart[] = Array.from({ length: MAX_ATTACHMENTS + 1 }, () =>
+			imagePart(base64OfBytes(8)),
+		);
+		const res = validateUserContent(content);
+		expect(res.ok).toBe(false);
+		expect(res.errors.some((e) => e.code === "too-many")).toBe(true);
+	});
+
+	it("rejects when the total payload exceeds the request ceiling", () => {
+		// Several individually-legal PDFs that together exceed the total cap.
+		const each = Math.floor(MAX_TOTAL_ATTACHMENT_BYTES / 3);
+		const content: UserContentPart[] = [
+			imagePart(base64OfBytes(each), "application/pdf"),
+			imagePart(base64OfBytes(each), "application/pdf"),
+			imagePart(base64OfBytes(each), "application/pdf"),
+			imagePart(base64OfBytes(each), "application/pdf"),
+		];
+		const res = validateUserContent(content);
+		expect(res.ok).toBe(false);
+		expect(res.errors.some((e) => e.code === "total-too-large")).toBe(true);
+	});
+});