@convex-dev/agent/src/mapping.test.ts

A agent component for Convex.

import { describe, test, expect } from "vitest";
import {
  guessMimeType,
  serializeDataOrUrl,
  deserializeUrl,
  serializeMessage,
  deserializeMessage,
  serializeContent,
} from "./mapping.js";
import { api } from "./component/_generated/api.js";
import type { AgentComponent, ActionCtx } from "./client/types.js";
import { vMessage } from "./validators.js";
import fs from "fs";
import path from "path";
import type { SerializedContent } from "./mapping.js";
import { validate } from "convex-helpers/validators";

const testAssetsDir = path.join(__dirname, "../test-assets");
const testFiles = [
  "book.svg",
  "bump.jpeg",
  "stack.png",
  "favicon.ico",
  "convex-logo.svg",
  "stack-light@3x.webp",
];

function fileToArrayBuffer(filePath: string): ArrayBuffer {
  const buf = fs.readFileSync(filePath);
  return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
}

describe("mapping", () => {
  test("infers correct mimeType for all test-assets", () => {
    const expected: { [key: string]: string } = {
      "book.svg": "image/svg+xml", // <svg
      "bump.jpeg": "image/jpeg",
      "stack.png": "image/png",
      "favicon.ico": "application/octet-stream", // fallback for ico
      "convex-logo.svg": "image/svg+xml", // <?xm
      "stack-light@3x.webp": "image/webp",
      "cat.gif": "image/gif",
    };
    for (const file of testFiles) {
      const ab = fileToArrayBuffer(path.join(testAssetsDir, file));
      const mime = guessMimeType(ab);
      expect(mime).toBe(expected[file]);
    }
  });

  test("turns Uint8Array into ArrayBuffer and round-trips", () => {
    const arr = new Uint8Array([1, 2, 3, 4, 5]);
    // serializeDataOrUrl should return the same ArrayBuffer
    const ser = serializeDataOrUrl(arr);
    expect(ser).toBeInstanceOf(ArrayBuffer);
    expect(new Uint8Array(ser as ArrayBuffer)).toEqual(arr);
    // deserializeUrl should return the same ArrayBuffer
    const deser = deserializeUrl(ser);
    expect(deser).toBeInstanceOf(ArrayBuffer);
    expect(new Uint8Array(deser as ArrayBuffer)).toEqual(arr);
  });

  test("round-trip serialize/deserialize message", async () => {
    const message = {
      role: "user" as const,
      content: "hello world",
      providerOptions: {},
    };
    // Fake ctx and component
    const ctx = {
      runAction: async () => undefined,
      runMutation: async () => undefined,
      storage: {
        store: async () => "storageId",
        getUrl: async () => "https://example.com/file",
        delete: async () => undefined,
      },
    } as unknown as ActionCtx;
    const component = api as unknown as AgentComponent;
    const { message: ser } = await serializeMessage(ctx, component, message);
    // Use is for type validation
    expect(validate(vMessage, ser)).toBeTruthy();
    const round = deserializeMessage(ser);
    expect(round).toEqual(message);
  });

  test("saving files returns fileIds when too big", async () => {
    // Make a big file
    const bigArr = new Uint8Array(1024 * 65).fill(1);
    const ab = bigArr.buffer.slice(
      bigArr.byteOffset,
      bigArr.byteOffset + bigArr.byteLength,
    );
    let called = false;
    const ctx = {
      runAction: async () => undefined,
      runMutation: async (_fn: unknown, _args: unknown) => {
        called = true;
        return { fileId: "file-123", storageId: "storage-123" };
      },
      storage: {
        store: async () => "storageId",
        getUrl: async () => "https://example.com/file",
        delete: async () => undefined,
      },
    } as unknown as ActionCtx;
    const component = api as unknown as AgentComponent;
    const content = [
      {
        type: "file" as const,
        data: ab,
        filename: "bigfile.bin",
        mimeType: "application/octet-stream",
        providerOptions: {},
      },
    ];
    const { content: ser, fileIds } = await serializeContent(
      ctx,
      component,
      content,
    );
    expect(called).toBe(true);
    expect(fileIds).toEqual(["file-123"]);
    // Should have replaced data with a URL
    const serArr = ser as SerializedContent;
    expect(typeof (serArr as { data: unknown }[])[0].data).toBe("string");
    expect((serArr as { data: unknown }[])[0].data as string).toMatch(
      /^https?:\/\//,
    );
  });

  test("sanity: fileIds are not returned for small files", async () => {
    const arr = new Uint8Array([1, 2, 3, 4, 5]);
    const ab = arr.buffer.slice(
      arr.byteOffset,
      arr.byteOffset + arr.byteLength,
    );
    const ctx = {
      runAction: async () => undefined,
      runMutation: async () => ({
        fileId: "file-123",
        storageId: "storage-123",
      }),
      storage: {
        store: async () => "storageId",
        getUrl: async () => "https://example.com/file",
        delete: async () => undefined,
      },
    } as unknown as ActionCtx;
    const component = api as unknown as AgentComponent;
    const content = [
      {
        type: "file" as const,
        data: ab,
        filename: "smallfile.bin",
        mimeType: "application/octet-stream",
        providerOptions: {},
      },
    ];
    const { fileIds } = await serializeContent(ctx, component, content);
    expect(fileIds).toBeUndefined();
  });
});