refactor(gateway): return implicit index.html (#2217)

BREAKING CHANGE: Gateway now implicitly responds with the contents of `/index.html` when accessing a directory `/` instead of redirecting to `/index.html`.

This changes current logic (redirect to index.html) to match what
go-ipfs does (return index.html without changing URL)

We also ensure directory URLs always end with '/'

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

src/http/gateway/resources/gateway.js

@@ -56,10 +56,11 @@ module.exports = {
     // so we convert /ipns/ to /ipfs/ before passing it to the resolver ¯\_(ツ)_/¯
     // This could be removed if a solution proposed in
     //  https://github.com/ipfs/js-ipfs-http-response/issues/22 lands upstream
-    const ipfsPath = decodeURI(path.startsWith('/ipns/')
+    let ipfsPath = decodeURI(path.startsWith('/ipns/')
       ? await ipfs.name.resolve(path, { recursive: true })
       : path)
 
+    let directory = false
     let data
     try {
       data = await resolver.cid(ipfs, ipfsPath)
@@ -70,22 +71,23 @@ module.exports = {
       // switch case with true feels so wrong.
       switch (true) {
         case (errorToString === 'Error: This dag node is a directory'):
+          directory = true
           data = await resolver.directory(ipfs, ipfsPath, err.cid)
 
           if (typeof data === 'string') {
             // no index file found
             if (!path.endsWith('/')) {
-              // for a directory, if URL doesn't end with a /
-              // append / and redirect permanent to that URL
+              // add trailing slash for directory listings
               return h.redirect(`${path}/`).permanent(true)
             }
             // send directory listing
             return h.response(data)
           }
 
-          // found index file
-          // redirect to URL/<found-index-file>
-          return h.redirect(PathUtils.joinURLParts(path, data[0].Name))
+          // found index file: return <ipfsPath>/<found-index-file>
+          ipfsPath = PathUtils.joinURLParts(ipfsPath, data[0].Name)
+          data = await resolver.cid(ipfs, ipfsPath)
+          break
         case (errorToString.startsWith('Error: no link named')):
           throw Boom.boomify(err, { statusCode: 404 })
         case (errorToString.startsWith('Error: multihash length inconsistent')):
@@ -97,10 +99,14 @@ module.exports = {
       }
     }
 
-    if (path.endsWith('/')) {
+    if (!directory && path.endsWith('/')) {
       // remove trailing slash for files
       return h.redirect(PathUtils.removeTrailingSlash(path)).permanent(true)
     }
+    if (directory && !path.endsWith('/')) {
+      // add trailing slash for directories with implicit index.html
+      return h.redirect(`${path}/`).permanent(true)
+    }
 
     // Support If-None-Match & Etag (Conditional Requests from RFC7232)
     // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag
@@ -153,7 +159,7 @@ module.exports = {
           log.error(err)
           return reject(err)
         }
-        resolve({ peekedStream, contentType: detectContentType(path, streamHead) })
+        resolve({ peekedStream, contentType: detectContentType(ipfsPath, streamHead) })
       })
     })
 
@@ -170,7 +176,8 @@ module.exports = {
       res.header('Cache-Control', 'public, max-age=29030400, immutable')
     }
 
-    log('path ', path)
+    log('HTTP path ', path)
+    log('IPFS path ', ipfsPath)
     log('content-type ', contentType)
 
     if (contentType) {

test/gateway/index.js

@@ -519,20 +519,40 @@ describe('HTTP Gateway', function () {
     expect(res.headers['x-ipfs-path']).to.equal(undefined)
   })
 
-  // TODO: check if interop for this exists and if not, match behavior of go-ipfs
-  it('redirect to webpage index.html', async () => {
-    const dir = 'QmbQD7EMEL1zeebwBsWEfA3ndgSS6F7S6iTuwuqasPgVRi/'
+  it('redirect to a directory with index.html', async () => {
+    const dir = 'QmbQD7EMEL1zeebwBsWEfA3ndgSS6F7S6iTuwuqasPgVRi' // note lack of '/' at the end
 
     const res = await gateway.inject({
       method: 'GET',
       url: '/ipfs/' + dir
     })
 
-    expect(res.statusCode).to.equal(302)
-    expect(res.headers.location).to.equal('/ipfs/QmbQD7EMEL1zeebwBsWEfA3ndgSS6F7S6iTuwuqasPgVRi/index.html')
+    // we expect redirect to the same path but with '/' at the end
+    expect(res.statusCode).to.equal(301)
+    expect(res.headers.location).to.equal(`/ipfs/${dir}/`)
     expect(res.headers['x-ipfs-path']).to.equal(undefined)
   })
 
+  it('load a directory with index.html', async () => {
+    const dir = 'QmbQD7EMEL1zeebwBsWEfA3ndgSS6F7S6iTuwuqasPgVRi/' // note '/' at the end
+
+    const res = await gateway.inject({
+      method: 'GET',
+      url: '/ipfs/' + dir
+    })
+
+    // confirm payload is index.html
+    expect(res.statusCode).to.equal(200)
+    expect(res.headers['content-type']).to.equal('text/html; charset=utf-8')
+    expect(res.headers['x-ipfs-path']).to.equal('/ipfs/' + dir)
+    expect(res.headers['cache-control']).to.equal('public, max-age=29030400, immutable')
+    expect(res.headers['last-modified']).to.equal('Thu, 01 Jan 1970 00:00:01 GMT')
+    expect(res.headers['content-length']).to.equal(res.rawPayload.length)
+    expect(res.headers.etag).to.equal('"Qma6665X5k3zti8nKy7gmXK2BndNDSkgmANpV6k3FUjUeg"')
+    expect(res.headers.suborigin).to.equal('ipfs000bafybeigccfheqv7upr4k64bkg5b5wiwelunyn2l2rbirmm43m34lcpuqqe')
+    expect(res.rawPayload).to.deep.equal(directoryContent['index.html'])
+  })
+
   it('test(gateway): load from URI-encoded path', async () => {
     // non-ascii characters will be URI-encoded by the browser
     const utf8path = '/ipfs/QmaRdtkDark8TgXPdDczwBneadyF44JvFGbrKLTkmTUhHk/cat-with-óąśśł-and-أعظم._.jpg'