test(canvas/chat): add AttachmentTextPreview coverage (12 cases)

Adds Vitest coverage for AttachmentTextPreview — inline text/code
preview with streaming fetch and expand/truncate.

Covers:
  - Loading skeleton (320x80) with aria-label
  - Ready state with correct text content
  - Filename shown in header
  - Expand button appears when lines > 10
  - Expand button hidden when all lines shown
  - Expand button updates display to full content
  - Download button calls onDownload
  - tone=user -> blue/accent border
  - tone=agent -> neutral border
  - Truncated notice when file exceeds 256 KB
  - Error -> AttachmentChip fallback
  - Cleanup on unmount

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This commit is contained in:
Molecule AI · core-uiux 2026-05-12 00:55:14 +00:00
parent 45e9c8d30f
commit 5489a0b276

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@ -0,0 +1,419 @@
// @vitest-environment jsdom
/**
* AttachmentTextPreview inline text/code preview with expand + truncate.
*
* Uses a streaming fetch (ReadableStream) to read up to 256 KB of text.
* State machine: idle loading ready/error. Ready state shows a
* monospace preview of the first 10 lines, with an expand button when
* there are more. Shows a "truncated" note when the file exceeds 256 KB.
* Error falls back to AttachmentChip.
*
* NOTE: No @testing-library/jest-dom import use DOM APIs for assertions.
*
* Covers:
* - Renders loading skeleton (320×80) with aria-label
* - Renders text preview with correct content in ready state
* - Shows filename in header
* - Expand button appears when lines > 10
* - Expand button hidden when all lines shown
* - Expand button calls setExpanded(true) and button text updates
* - Download button calls onDownload
* - tone=user applies blue/accent border
* - tone=agent applies neutral border
* - Error state renders AttachmentChip fallback
* - Cleans up on unmount
*/
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import { cleanup, fireEvent, render, waitFor } from "@testing-library/react";
import React from "react";
import { AttachmentTextPreview } from "../AttachmentTextPreview";
import type { ChatAttachment } from "../types";
// ─── Mocks ────────────────────────────────────────────────────────────────────
const mockResolveAttachmentHref = vi.fn<(id: string, uri: string) => string>(
(id, uri) => `https://api.moleculesai.app/attachments/${uri}`,
);
const mockIsPlatformAttachment = vi.fn<(uri: string) => boolean>(() => true);
vi.mock("../uploads", () => ({
isPlatformAttachment: (uri: string) => mockIsPlatformAttachment(uri),
resolveAttachmentHref: (id: string, uri: string) =>
mockResolveAttachmentHref(id, uri),
}));
vi.mock("@/lib/api", () => ({
platformAuthHeaders: () => ({ Authorization: "Bearer test-token" }),
}));
// ─── Helpers ──────────────────────────────────────────────────────────────────
function makeAttachment(name: string, size?: number): ChatAttachment {
return { name, uri: `workspace:/tmp/${name}`, size };
}
beforeEach(() => {
mockIsPlatformAttachment.mockReturnValue(true);
mockResolveAttachmentHref.mockReturnValue(
(id: string, uri: string) => `https://api.moleculesai.app/attachments/${uri}`,
);
});
afterEach(() => {
cleanup();
});
// ─── Fetch mock helpers ───────────────────────────────────────────────────────
/**
* Mock a streaming fetch that returns text content.
* Mimics ReadableStream.read() yielding text chunks.
*/
function mockFetchText(completeText: string) {
const encoder = new TextEncoder();
const chunks: Uint8Array[] = [];
// Yield in 50-byte chunks
let offset = 0;
while (offset < completeText.length) {
chunks.push(encoder.encode(completeText.slice(offset, offset + 50)));
offset += 50;
}
let chunkIndex = 0;
const mockReader = {
read: vi.fn<() => Promise<{ done: boolean; value?: Uint8Array }>>(
async () => {
if (chunkIndex < chunks.length) {
return { done: false, value: chunks[chunkIndex++] };
}
return { done: true };
},
),
cancel: vi.fn(),
};
const mockBody = {
getReader: vi.fn(() => mockReader),
};
global.fetch = vi.fn(() =>
Promise.resolve({
ok: true,
status: 200,
body: mockBody,
headers: new Map([["content-type", "text/plain"]]),
}) as unknown as Response,
);
return mockReader;
}
function mockFetchError() {
global.fetch = vi.fn(() =>
Promise.resolve({ ok: false, status: 500 }) as unknown as Response,
);
}
/**
* Mock a fetch where body.getReader() returns null (no streaming body).
*/
function mockFetchTextNoBody(text: string) {
const encoder = new TextEncoder();
global.fetch = vi.fn(() =>
Promise.resolve({
ok: true,
status: 200,
body: null,
text: () => Promise.resolve(text),
headers: new Map([["content-type", "text/plain"]]),
}) as unknown as Response,
);
}
// ─── Loading / idle state ─────────────────────────────────────────────────────
describe("AttachmentTextPreview — loading/idle", () => {
it("renders loading skeleton (320×80) with aria-label", () => {
mockFetchText("hello world");
const att = makeAttachment("log.txt", 1024);
const { container } = render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
const skeleton = container.querySelector('[aria-label]') as HTMLElement;
expect(skeleton?.getAttribute("aria-label")).toContain("log.txt");
expect(skeleton?.getAttribute("aria-label")).toContain("Loading");
expect(skeleton?.style.width).toBe("320px");
expect(skeleton?.style.height).toBe("80px");
});
});
// ─── Ready state ───────────────────────────────────────────────────────────────
describe("AttachmentTextPreview — ready", () => {
beforeEach(() => {
mockFetchText("hello world");
});
it("renders text preview with correct content", async () => {
mockFetchText("line1\nline2\nline3");
const att = makeAttachment("log.txt");
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
const code = document.querySelector("code");
expect(code).toBeTruthy();
});
const code = document.querySelector("code");
expect(code?.textContent).toContain("line1");
});
it("shows filename in header", async () => {
mockFetchText("hello");
const att = makeAttachment("config.yaml");
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
expect(document.querySelector("code")).toBeTruthy();
});
// Header should contain the filename
const header = document.querySelector("code")?.closest("div");
expect(header?.textContent).toContain("config.yaml");
});
it("shows expand button when lines > 10", async () => {
const longText = Array.from({ length: 15 }, (_, i) => `line ${i + 1}`).join("\n");
mockFetchText(longText);
const att = makeAttachment("long.txt");
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
const btn = document.querySelector("button");
expect(btn).toBeTruthy();
});
// Should have a button saying "Show all N lines"
const btns = Array.from(document.querySelectorAll("button"));
const expandBtn = btns.find((b) => b.textContent?.includes("Show all"));
expect(expandBtn).toBeTruthy();
expect(expandBtn?.textContent).toContain("15 lines");
});
it("hides expand button when all lines shown (<= 10)", async () => {
const shortText = Array.from({ length: 5 }, (_, i) => `line ${i + 1}`).join("\n");
mockFetchText(shortText);
const att = makeAttachment("short.txt");
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
expect(document.querySelector("code")).toBeTruthy();
});
const btns = Array.from(document.querySelectorAll("button"));
const expandBtn = btns.find((b) => b.textContent?.includes("Show all"));
expect(expandBtn).toBeUndefined();
});
it("expand button updates button text to all lines", async () => {
const longText = Array.from({ length: 15 }, (_, i) => `line ${i + 1}`).join("\n");
mockFetchText(longText);
const att = makeAttachment("long.txt");
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
const btns = Array.from(document.querySelectorAll("button"));
expect(btns.find((b) => b.textContent?.includes("Show all"))).toBeTruthy();
});
const btns = Array.from(document.querySelectorAll("button"));
const expandBtn = btns.find((b) => b.textContent?.includes("Show all")) as HTMLButtonElement;
expandBtn.click();
await vi.waitFor(() => {
const newBtns = Array.from(document.querySelectorAll("button"));
expect(newBtns.find((b) => b.textContent?.includes("Show all"))).toBeUndefined();
});
});
it("download button calls onDownload", async () => {
mockFetchText("hello");
const onDownload = vi.fn();
const att = makeAttachment("log.txt");
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={onDownload}
tone="user"
/>,
);
await vi.waitFor(() => {
expect(document.querySelector("code")).toBeTruthy();
});
// Find the download button (aria-label contains "Download")
const downloadBtn = document.querySelector('[aria-label^="Download"]') as HTMLButtonElement;
expect(downloadBtn).toBeTruthy();
downloadBtn.click();
expect(onDownload).toHaveBeenCalledWith(att);
});
it("tone=user applies blue/accent border classes", async () => {
mockFetchText("hello");
const att = makeAttachment("log.txt");
const { container } = render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
expect(document.querySelector("code")).toBeTruthy();
});
const rootDiv = container.firstChild as HTMLElement;
expect(rootDiv.className).toContain("border-blue-400");
expect(rootDiv.className).toContain("accent-strong");
});
it("tone=agent applies neutral border class (no blue)", async () => {
mockFetchText("hello");
const att = makeAttachment("log.txt");
const { container } = render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="agent"
/>,
);
await vi.waitFor(() => {
expect(document.querySelector("code")).toBeTruthy();
});
const rootDiv = container.firstChild as HTMLElement;
expect(rootDiv.className).not.toContain("border-blue-400");
});
});
// ─── Truncated state ───────────────────────────────────────────────────────────
describe("AttachmentTextPreview — truncated", () => {
it("shows truncated notice when file exceeds 256 KB", async () => {
// Simulate a response where the reader yields chunks until MAX_FETCH_BYTES (256KB)
const encoder = new TextEncoder();
const bytesNeeded = 256 * 1024;
const mockReader = {
read: vi.fn<() => Promise<{ done: boolean; value?: Uint8Array }>>(
async () => {
// Return one chunk that's >= 256KB total (we'll cap at MAX_FETCH_BYTES)
const chunk = encoder.encode("x".repeat(300 * 1024));
return { done: false, value: chunk };
},
),
cancel: vi.fn(),
};
const mockBody = { getReader: vi.fn(() => mockReader) };
global.fetch = vi.fn(() =>
Promise.resolve({
ok: true,
status: 200,
body: mockBody,
headers: new Map([["content-type", "text/plain"]]),
}) as unknown as Response,
);
const att = makeAttachment("huge.log");
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
const truncated = document.querySelector("code");
expect(truncated).toBeTruthy();
});
// Should show truncated notice
const truncatedNote = Array.from(document.querySelectorAll("button")).find(
(b) => b.textContent?.includes("download full file"),
);
expect(truncatedNote).toBeTruthy();
});
});
// ─── Error state ───────────────────────────────────────────────────────────────
describe("AttachmentTextPreview — error", () => {
it("renders AttachmentChip fallback when fetch fails", async () => {
mockFetchError();
const onDownload = vi.fn();
const att = makeAttachment("broken.txt", 256);
render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={onDownload}
tone="agent"
/>,
);
await vi.waitFor(() => {
const chip = document.querySelector("button");
expect(chip).toBeTruthy();
expect(chip?.textContent).toContain("broken.txt");
});
const chip = document.querySelector("button") as HTMLButtonElement;
chip.click();
expect(onDownload).toHaveBeenCalledWith(att);
});
});
// ─── Cleanup ──────────────────────────────────────────────────────────────────
describe("AttachmentTextPreview — cleanup", () => {
it("cleans up on unmount", async () => {
mockFetchText("hello");
const att = makeAttachment("log.txt");
const { unmount } = render(
<AttachmentTextPreview
workspaceId="ws1"
attachment={att}
onDownload={vi.fn()}
tone="user"
/>,
);
await vi.waitFor(() => {
expect(document.querySelector("code")).toBeTruthy();
});
expect(document.querySelector("code")).toBeTruthy();
unmount();
expect(document.querySelector("code")).toBeNull();
});
});