fix: return HTML for browser Accept headers on root route (#532)

.changeset/red-dancers-ask.md

@@ -0,0 +1,2 @@
+---
+---

src/handlers/request-handlers/root-request-handler.ts

@@ -1,4 +1,3 @@
-import accepts from 'accepts'
 import { NextFunction, Request, Response } from 'express'
 import { path, pathEq } from 'ramda'
 import { createSettings } from '../../factories/settings-factory'
@@ -8,10 +7,40 @@ import { fromBech32 } from '../../utils/transform'
 import { getTemplate } from '../../utils/template-cache'
 import packageJson from '../../../package.json'
 
+export const hasExplicitNostrJsonAcceptHeader = (request: Request): boolean => {
+  const acceptHeader = request.headers.accept
+
+  if (!acceptHeader) {
+    return false
+  }
+
+  const acceptHeaderValue = Array.isArray(acceptHeader) ? acceptHeader.join(',') : acceptHeader
+
+  return acceptHeaderValue.split(',').some((token) => {
+    const [mediaType, ...params] = token
+      .split(';')
+      .map((value) => value.trim().toLowerCase())
+
+    if (mediaType !== 'application/nostr+json') {
+      return false
+    }
+
+    const quality = params.find((param) => param.startsWith('q='))
+
+    if (!quality) {
+      return true
+    }
+
+    const qValue = Number.parseFloat(quality.slice(2))
+
+    return !Number.isNaN(qValue) && qValue > 0
+  })
+}
+
 export const rootRequestHandler = (request: Request, response: Response, next: NextFunction) => {
   const settings = createSettings()
 
-  if (accepts(request).type(['application/nostr+json'])) {
+  if (hasExplicitNostrJsonAcceptHeader(request)) {
     const {
       info: { name, description, pubkey: rawPubkey, contact, relay_url },
     } = settings

src/routes/index.ts

@@ -1,4 +1,3 @@
-import accepts from 'accepts'
 import express from 'express'
 
 import { nodeinfo21Handler, nodeinfoHandler } from '../handlers/request-handlers/nodeinfo-handler'
@@ -9,12 +8,12 @@ import { getPrivacyRequestHandler } from '../handlers/request-handlers/get-priva
 import { getTermsRequestHandler } from '../handlers/request-handlers/get-terms-request-handler'
 import invoiceRouter from './invoices'
 import { rateLimiterMiddleware } from '../handlers/request-handlers/rate-limiter-middleware'
-import { rootRequestHandler } from '../handlers/request-handlers/root-request-handler'
+import { hasExplicitNostrJsonAcceptHeader, rootRequestHandler } from '../handlers/request-handlers/root-request-handler'
 
 const router = express.Router()
 
 router.use((req, res, next) => {
-  if (req.method === 'GET' && accepts(req).type(['application/nostr+json'])) {
+  if (req.method === 'GET' && req.path === '/' && hasExplicitNostrJsonAcceptHeader(req)) {
     return rootRequestHandler(req, res, next)
   }
   next()

test/integration/features/nip-11/nip-11.feature

@@ -14,6 +14,11 @@ Feature: NIP-11
     Then the response Content-Type does not include "application/nostr+json"
     And the response body is not a relay information document
 
+  Scenario: Relay serves HTML for typical browser Accept header
+    When a browser requests the root path
+    Then the response Content-Type includes "text/html"
+    And the response body is not a relay information document
+
   Scenario: Relay information document reports max_filters from settings
     When a client requests the relay information document
     Then the limitation object contains a max_filters field

test/integration/features/nip-11/nip-11.feature.ts

@@ -29,6 +29,16 @@ When('a client requests the root path with Accept header {string}', async functi
   this.parameters.httpResponse = response
 })
 
+When('a browser requests the root path', async function(this: World<Record<string, any>>) {
+  const response: AxiosResponse = await axios.get(BASE_URL, {
+    headers: {
+      Accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8',
+    },
+    validateStatus: () => true,
+  })
+  this.parameters.httpResponse = response
+})
+
 Then('the response status is {int}', function(this: World<Record<string, any>>, status: number) {
   expect(this.parameters.httpResponse.status).to.equal(status)
 })

test/unit/handlers/request-handlers/root-request-handler.spec.ts

@@ -7,7 +7,10 @@ const { expect } = chai
 
 import * as settingsFactory from '../../../../src/factories/settings-factory'
 import * as templateCache from '../../../../src/utils/template-cache'
-import { rootRequestHandler } from '../../../../src/handlers/request-handlers/root-request-handler'
+import {
+  hasExplicitNostrJsonAcceptHeader,
+  rootRequestHandler,
+} from '../../../../src/handlers/request-handlers/root-request-handler'
 
 const baseSettings = {
   info: {
@@ -40,6 +43,23 @@ const settingsWithFee = {
   },
 }
 
+describe('hasExplicitNostrJsonAcceptHeader', () => {
+  it('returns true for explicit application/nostr+json', () => {
+    expect(hasExplicitNostrJsonAcceptHeader({ headers: { accept: 'application/nostr+json' } } as any)).to.equal(true)
+  })
+
+  it('returns false for typical browser Accept header', () => {
+    const browserAcceptHeader =
+      'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8'
+
+    expect(hasExplicitNostrJsonAcceptHeader({ headers: { accept: browserAcceptHeader } } as any)).to.equal(false)
+  })
+
+  it('returns false when q=0 for application/nostr+json', () => {
+    expect(hasExplicitNostrJsonAcceptHeader({ headers: { accept: 'application/nostr+json;q=0' } } as any)).to.equal(false)
+  })
+})
+
 describe('rootRequestHandler', () => {
   let createSettingsStub: sinon.SinonStub
   let getTemplateStub: sinon.SinonStub