test title

// Copyright 2020-2022 Signal Messenger, LLC // SPDX-License-Identifier: AGPL-3.0-only import { assert } from 'chai'; import { Response } from 'node-fetch'; import * as sinon from 'sinon'; import * as fs from 'fs'; import * as path from 'path'; import AbortController from 'abort-controller'; import { IMAGE_JPEG, stringToMIMEType } from '../../types/MIME'; import type { LoggerType } from '../../types/Logging'; import { fetchLinkPreviewImage, fetchLinkPreviewMetadata, } from '../../linkPreviews/linkPreviewFetch'; describe('link preview fetching', () => { // We'll use this to create a fake `fetch`. We'll want to call `.resolves` or // `.rejects` on it (meaning that it needs to be a Sinon Stub type), but we'll also // want it to be a fake `fetch`. `any` seems like the best "supertype" there. // eslint-disable-next-line @typescript-eslint/no-explicit-any function stub(): any { return sinon.stub(); } let warn: sinon.SinonStub; let logger: Pick; beforeEach(() => { warn = sinon.stub(); logger = { warn }; }); describe('fetchLinkPreviewMetadata', () => { const makeHtml = (stuffInHead: ReadonlyArray = []) => ` ${stuffInHead.join('\n')} should be ignored `; const makeResponse = ({ status = 200, headers = {}, body = makeHtml(['test title']), url = 'https://example.com', }: { status?: number; headers?: { [key: string]: null | string }; body?: null | string | Uint8Array | AsyncIterable; url?: string; } = {}) => { let bodyLength: null | number; let bodyStream: null | AsyncIterable; if (!body) { bodyLength = 0; bodyStream = null; } else if (typeof body === 'string') { const asBytes = new TextEncoder().encode(body); bodyLength = asBytes.length; bodyStream = (async function* stream() { yield asBytes; })(); } else if (body instanceof Uint8Array) { bodyLength = body.length; bodyStream = (async function* stream() { yield body; })(); } else { bodyLength = null; bodyStream = body; } const headersObj = new Headers(); Object.entries({ 'Content-Type': 'text/html; charset=utf-8', 'Content-Length': bodyLength === null ? null : String(bodyLength), ...headers, }).forEach(([headerName, headerValue]) => { if (headerValue) { headersObj.set(headerName, headerValue); } }); return { headers: headersObj, body: bodyStream, ok: status >= 200 && status <= 299, status, url, }; }; it('handles the "kitchen sink" of results', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ '', '', '', '', ]), }) ); assert.deepEqual( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), { title: 'test title', description: 'test description', date: 1587386096009, imageHref: 'https://example.com/image.jpg', } ); }); it('handles image href sources in the correct order', async () => { const orderedImageHrefSources = [ { tag: '', expectedHref: 'https://example.com/og-image.jpg', }, { tag: '', expectedHref: 'https://example.com/og-image-url.jpg', }, { tag: '', expectedHref: 'https://example.com/apple-touch-icon.jpg', }, { tag: '', expectedHref: 'https://example.com/apple-touch-icon-precomposed.jpg', }, { tag: '', expectedHref: 'https://example.com/shortcut-icon.jpg', }, { tag: '', expectedHref: 'https://example.com/icon.jpg', }, ]; for (let i = orderedImageHrefSources.length - 1; i >= 0; i -= 1) { const imageTags = orderedImageHrefSources .slice(i) .map(({ tag }) => tag) // Reverse the array to make sure that we're prioritizing properly, // instead of just using whichever comes first. .reverse(); const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ '', ...imageTags, ]), }) ); // eslint-disable-next-line no-await-in-loop const val = await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ); assert.propertyVal( val, 'imageHref', orderedImageHrefSources[i].expectedHref ); } }); it('logs no warnings if everything goes smoothly', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ '', '', '', '', ]), }) ); await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ); sinon.assert.notCalled(warn); }); it('sends WhatsApp as the User-Agent for compatibility', async () => { const fakeFetch = stub().resolves(makeResponse()); await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ); sinon.assert.calledWith( fakeFetch, 'https://example.com', sinon.match({ headers: { 'User-Agent': 'WhatsApp/2', }, }) ); }); it('returns null if the request fails', async () => { const fakeFetch = stub().rejects(new Error('Test request failure')); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, 'fetchLinkPreviewMetadata: failed to fetch link preview HTML; bailing' ); }); it("returns null if the response status code isn't 2xx", async () => { await Promise.all( [100, 304, 400, 404, 500, 0, -200].map(async status => { const fakeFetch = stub().resolves(makeResponse({ status })); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ) ); sinon.assert.calledWith( warn, `fetchLinkPreviewMetadata: got a ${status} status code; bailing` ); }) ); }); it("doesn't use fetch's automatic redirection behavior", async () => { const fakeFetch = stub().resolves(makeResponse()); await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ); sinon.assert.calledWith( fakeFetch, 'https://example.com', sinon.match({ redirect: 'manual' }) ); }); [301, 302, 303, 307, 308].forEach(status => { it(`handles ${status} redirects`, async () => { const fakeFetch = stub(); fakeFetch.onFirstCall().resolves( makeResponse({ status, headers: { Location: 'https://example.com/2' }, body: null, }) ); fakeFetch.onSecondCall().resolves(makeResponse()); assert.deepEqual( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), { title: 'test title', description: null, date: null, imageHref: null, } ); sinon.assert.calledTwice(fakeFetch); sinon.assert.calledWith(fakeFetch.getCall(0), 'https://example.com'); sinon.assert.calledWith(fakeFetch.getCall(1), 'https://example.com/2'); }); it(`returns null when seeing a ${status} status with no Location header`, async () => { const fakeFetch = stub().resolves(makeResponse({ status })); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ) ); }); }); it('handles relative redirects', async () => { const fakeFetch = stub(); fakeFetch.onFirstCall().resolves( makeResponse({ status: 301, headers: { Location: '/2/' }, body: null, }) ); fakeFetch.onSecondCall().resolves( makeResponse({ status: 301, headers: { Location: '3' }, body: null, }) ); fakeFetch.onThirdCall().resolves(makeResponse()); assert.deepEqual( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), { title: 'test title', description: null, date: null, imageHref: null, } ); sinon.assert.calledThrice(fakeFetch); sinon.assert.calledWith(fakeFetch.getCall(0), 'https://example.com'); sinon.assert.calledWith(fakeFetch.getCall(1), 'https://example.com/2/'); sinon.assert.calledWith(fakeFetch.getCall(2), 'https://example.com/2/3'); }); it('returns null if redirecting to an insecure HTTP URL', async () => { const fakeFetch = stub().resolves( makeResponse({ status: 301, headers: { Location: 'http://example.com' }, body: null, }) ); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ) ); sinon.assert.calledOnce(fakeFetch); }); it("returns null if there's a redirection loop", async () => { const fakeFetch = stub(); fakeFetch.onFirstCall().resolves( makeResponse({ status: 301, headers: { Location: '/2/' }, body: null, }) ); fakeFetch.onSecondCall().resolves( makeResponse({ status: 301, headers: { Location: '/start' }, body: null, }) ); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com/start', new AbortController().signal ) ); sinon.assert.calledTwice(fakeFetch); }); it('returns null if redirecting more than 20 times', async () => { const fakeFetch = stub().callsFake(async () => makeResponse({ status: 301, headers: { Location: `/${Math.random()}` }, body: null, }) ); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com/start', new AbortController().signal ) ); sinon.assert.callCount(fakeFetch, 20); }); it('returns null if the response has no body', async () => { const fakeFetch = stub().resolves(makeResponse({ body: null })); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ) ); sinon.assert.calledWith( warn, 'fetchLinkPreviewMetadata: no response body; bailing' ); }); it('returns null if the result body is too short', async () => { const fakeFetch = stub().resolves(makeResponse({ body: '' })); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, 'fetchLinkPreviewMetadata: Content-Length is too short; bailing' ); }); it('returns null if the result is meant to be downloaded', async () => { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Disposition': 'attachment' }, }) ); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, 'fetchLinkPreviewMetadata: Content-Disposition header is not inline; bailing' ); }); it('allows an explicitly inline Content-Disposition header', async () => { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Disposition': 'inline' }, }) ); assert.deepEqual( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), { title: 'test title', description: null, date: null, imageHref: null, } ); }); it('returns null if the Content-Type is not HTML', async () => { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/plain' }, }) ); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, 'fetchLinkPreviewMetadata: Content-Type is not HTML; bailing' ); }); it('accepts non-lowercase Content-Type headers', async () => { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'TEXT/HTML; chArsEt=utf-8' }, }) ); assert.deepEqual( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), { title: 'test title', description: null, date: null, imageHref: null, } ); }); it('parses the response as UTF-8 if the body contains a byte order mark', async () => { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html', }, body: (async function* body() { yield new Uint8Array([0xef, 0xbb, 0xbf]); yield new TextEncoder().encode( '<!doctype html><title>\u{1F389}' ); })(), }) ); assert.deepEqual( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), { title: '🎉', description: null, date: null, imageHref: null, } ); }); it('respects the UTF-8 byte order mark above the Content-Type header', async () => { const bom = new Uint8Array([0xef, 0xbb, 0xbf]); const titleHtml = new TextEncoder().encode('\u{1F389}'); const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html; charset=latin1', }, body: (async function* body() { yield bom; yield titleHtml; })(), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', '🎉' ); }); it('respects the UTF-8 byte order mark above a in the document', async () => { const bom = new Uint8Array([0xef, 0xbb, 0xbf]); const titleHtml = new TextEncoder().encode('\u{1F389}'); const endHeadHtml = new TextEncoder().encode(''); const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html', }, body: (async function* body() { yield bom; yield new TextEncoder().encode( '' ); yield titleHtml; yield endHeadHtml; })(), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', '🎉' ); }); it('respects the UTF-8 byte order mark above a in the document', async () => { const bom = new Uint8Array([0xef, 0xbb, 0xbf]); const titleHtml = new TextEncoder().encode('\u{1F389}'); const endHeadHtml = new TextEncoder().encode(''); const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html', }, body: (async function* body() { yield bom; yield new TextEncoder().encode( '' ); yield titleHtml; yield endHeadHtml; })(), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', '🎉' ); }); it('respects the Content-Type header above anything in the HTML', async () => { const titleHtml = new TextEncoder().encode('\u{1F389}'); const endHeadHtml = new TextEncoder().encode(''); { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html; charset=utf-8', }, body: (async function* body() { yield new TextEncoder().encode( '' ); yield titleHtml; yield endHeadHtml; })(), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', '🎉' ); } { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html; charset=utf-8', }, body: (async function* body() { yield new TextEncoder().encode( '' ); yield titleHtml; yield endHeadHtml; })(), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', '🎉' ); } }); it('prefers the Content-Type http-equiv in the HTML above ', async () => { const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html', }, body: makeHtml([ '', '', '\u{1F389}', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', '🎉' ); }); it('parses non-UTF8 encodings', async () => { const titleBytes = new Uint8Array([0x61, 0x71, 0x75, 0xed]); assert.notDeepEqual( new TextDecoder('utf8').decode(titleBytes), new TextDecoder('latin1').decode(titleBytes), 'Test data was not set up correctly' ); const fakeFetch = stub().resolves( makeResponse({ headers: { 'Content-Type': 'text/html; charset=latin1', }, body: (async function* body() { yield new TextEncoder().encode(''); yield titleBytes; yield new TextEncoder().encode(''); })(), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', 'aquí' ); }); it('handles incomplete bodies', async () => { const fakeFetch = stub().resolves( makeResponse({ body: (async function* body() { yield new TextEncoder().encode( 'foo bar { const shouldNeverBeCalled = sinon.stub(); const abortController = new AbortController(); const fakeFetch = stub().resolves( makeResponse({ body: (async function* body() { yield new TextEncoder().encode(''); abortController.abort(); yield new TextEncoder().encode('should be dropped'); shouldNeverBeCalled(); })(), }) ); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', abortController.signal ) ); sinon.assert.notCalled(shouldNeverBeCalled); }); it('stops reading bodies after 1000 kilobytes', async function test() { const shouldNeverBeCalled = sinon.stub(); const fakeFetch = stub().resolves( makeResponse({ body: (async function* body() { yield new TextEncoder().encode( 'foo bar' ); const spaces = new Uint8Array(250 * 1024).fill(32); yield spaces; yield spaces; yield spaces; yield spaces; yield spaces; shouldNeverBeCalled(); yield new TextEncoder().encode( '' ); })(), }) ); assert.deepEqual( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), { title: 'foo bar', description: null, date: null, imageHref: null, } ); sinon.assert.notCalled(shouldNeverBeCalled); }); it("returns null if the HTML doesn't contain a title, even if it contains other values", async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ '', '', ``, ]), }) ); assert.isNull( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, "parseMetadata: HTML document doesn't have a title; bailing" ); }); it('prefers og:title to document.title', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'ignored', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'title', 'foo bar' ); }); it('prefers og:description to ', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'description', 'bar' ); }); it('parses ', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'description', 'bar' ); }); it('ignores empty descriptions', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'description', null ); }); it('parses absolute image URLs', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'imageHref', 'https://example.com/image.jpg' ); }); it('parses relative image URLs', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'imageHref', 'https://example.com/assets/image.jpg' ); }); it('relative image URL resolution is relative to the final URL after redirects, not the original URL', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', ]), url: 'https://bar.example/assets/', }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://foo.example', new AbortController().signal ), 'imageHref', 'https://bar.example/assets/image.jpg' ); }); it('ignores empty image URLs', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'imageHref', null ); }); it('ignores blank image URLs', async () => { const fakeFetch = stub().resolves( makeResponse({ body: makeHtml([ 'foo', '', ]), }) ); assert.propertyVal( await fetchLinkPreviewMetadata( fakeFetch, 'https://example.com', new AbortController().signal ), 'imageHref', null ); }); }); describe('fetchLinkPreviewImage', () => { const readFixture = async (filename: string): Promise => { const result = await fs.promises.readFile( path.join(__dirname, '..', '..', '..', 'fixtures', filename) ); assert(result.length > 10, `Test failed to read fixture ${filename}`); return result; }; [ { title: 'JPEG', contentType: 'image/jpeg', fixtureFilename: 'kitten-1-64-64.jpg', }, { title: 'PNG', contentType: 'image/png', fixtureFilename: 'freepngs-2cd43b_bed7d1327e88454487397574d87b64dc_mv2.png', }, { title: 'GIF', contentType: 'image/gif', fixtureFilename: 'giphy-GVNvOUpeYmI7e.gif', }, { title: 'WEBP', contentType: 'image/webp', fixtureFilename: '512x515-thumbs-up-lincoln.webp', }, { title: 'ICO', contentType: 'image/x-icon', fixtureFilename: 'kitten-1-64-64.ico', }, ].forEach(({ title, contentType, fixtureFilename }) => { it(`handles ${title} images`, async () => { const fixture = await readFixture(fixtureFilename); const fakeFetch = stub().resolves( new Response(fixture, { headers: { 'Content-Type': contentType, 'Content-Length': fixture.length.toString(), }, }) ); assert.deepEqual( ( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal ) )?.contentType, stringToMIMEType(contentType) ); }); }); it('returns null if the request fails', async () => { const fakeFetch = stub().rejects(new Error('Test request failure')); assert.isNull( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, 'fetchLinkPreviewImage: failed to fetch image; bailing' ); }); it("returns null if the response status code isn't 2xx", async () => { const fixture = await readFixture('kitten-1-64-64.jpg'); await Promise.all( [400, 404, 500, 598].map(async status => { const fakeFetch = stub().resolves( new Response(fixture, { status, headers: { 'Content-Type': 'image/jpeg', 'Content-Length': fixture.length.toString(), }, }) ); assert.isNull( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal, logger ) ); sinon.assert.calledWith( warn, `fetchLinkPreviewImage: got a ${status} status code; bailing` ); }) ); }); // Most of the redirect behavior is tested above. it('handles 301 redirects', async () => { const fixture = await readFixture('kitten-1-64-64.jpg'); const fakeFetch = stub(); fakeFetch.onFirstCall().resolves( new Response(Buffer.from(''), { status: 301, headers: { Location: '/result.jpg', }, }) ); fakeFetch.onSecondCall().resolves( new Response(fixture, { headers: { 'Content-Type': IMAGE_JPEG, 'Content-Length': fixture.length.toString(), }, }) ); assert.deepEqual( ( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal ) )?.contentType, IMAGE_JPEG ); sinon.assert.calledTwice(fakeFetch); sinon.assert.calledWith(fakeFetch.getCall(0), 'https://example.com/img'); sinon.assert.calledWith( fakeFetch.getCall(1), 'https://example.com/result.jpg' ); }); it('returns null if the response is too small', async () => { const fakeFetch = stub().resolves( new Response(await readFixture('kitten-1-64-64.jpg'), { headers: { 'Content-Type': 'image/jpeg', 'Content-Length': '2', }, }) ); assert.isNull( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, 'fetchLinkPreviewImage: Content-Length is too short; bailing' ); }); it('returns null if the response is too large', async () => { const fakeFetch = stub().resolves( new Response(await readFixture('kitten-1-64-64.jpg'), { headers: { 'Content-Type': 'image/jpeg', 'Content-Length': '123456789', }, }) ); assert.isNull( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal, logger ) ); sinon.assert.calledOnce(warn); sinon.assert.calledWith( warn, 'fetchLinkPreviewImage: Content-Length is too large or is unset; bailing' ); }); it('returns null if the Content-Type is not a valid image', async () => { const fixture = await readFixture('kitten-1-64-64.jpg'); await Promise.all( ['', 'image/tiff', 'video/mp4', 'text/plain', 'application/html'].map( async contentType => { const fakeFetch = stub().resolves( new Response(fixture, { headers: { 'Content-Type': contentType, 'Content-Length': fixture.length.toString(), }, }) ); assert.isNull( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal, logger ) ); sinon.assert.calledWith( warn, 'fetchLinkPreviewImage: Content-Type is not an image; bailing' ); } ) ); }); it('sends WhatsApp as the User-Agent for compatibility', async () => { const fakeFetch = stub().resolves(new Response(Buffer.from(''))); await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', new AbortController().signal ); sinon.assert.calledWith( fakeFetch, 'https://example.com/img', sinon.match({ headers: { 'User-Agent': 'WhatsApp/2', }, }) ); }); it("doesn't read the image if the request was aborted before reading started", async () => { const abortController = new AbortController(); const fixture = await readFixture('kitten-1-64-64.jpg'); const fakeFetch = stub().callsFake(() => { const response = new Response(fixture, { headers: { 'Content-Type': 'image/jpeg', 'Content-Length': fixture.length.toString(), }, }); sinon .stub(response, 'buffer') .rejects(new Error('Should not be called')); sinon.stub(response, 'blob').rejects(new Error('Should not be called')); sinon.stub(response, 'text').rejects(new Error('Should not be called')); sinon.stub(response, 'body').get(() => { throw new Error('Should not be accessed'); }); abortController.abort(); return response; }); assert.isNull( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', abortController.signal ) ); }); it('returns null if the request was aborted after the image was read', async () => { const abortController = new AbortController(); const fixture = await readFixture('kitten-1-64-64.jpg'); const fakeFetch = stub().callsFake(() => { const response = new Response(fixture, { headers: { 'Content-Type': 'image/jpeg', 'Content-Length': fixture.length.toString(), }, }); const oldBufferMethod = response.buffer.bind(response); sinon.stub(response, 'buffer').callsFake(async () => { const data = await oldBufferMethod(); abortController.abort(); return data; }); return response; }); assert.isNull( await fetchLinkPreviewImage( fakeFetch, 'https://example.com/img', abortController.signal ) ); }); }); });