[Backport 7.x] Support mapbox content type (#1508)

Co-authored-by: Tomas Della Vedova <delvedor@users.noreply.github.com>

docs/transport.asciidoc

@@ -32,3 +32,10 @@ class MyTransport extends Transport {
 }
 ----
 
+==== Supported content types
+
+- `application/json`, in this case the transport will return a plain JavaScript object
+- `text/plain`, in this case the transport will return a plain string
+- `application/vnd.mapbox-vector-tile`, in this case the transport will return a Buffer
+- `application/vnd.elasticsearch+json`, in this case the transport will return a plain JavaScript object
+

lib/Transport.d.ts

@@ -155,8 +155,8 @@ export default class Transport {
   _nextSniff: number;
   _isSniffing: boolean;
   constructor(opts: TransportOptions);
-  request(params: TransportRequestParams, options?: TransportRequestOptions): TransportRequestPromise<ApiResponse>;
-  request(params: TransportRequestParams, options?: TransportRequestOptions, callback?: (err: ApiError, result: ApiResponse) => void): TransportRequestCallback;
+  request<TResponse = Record<string, any>, TContext = Context>(params: TransportRequestParams, options?: TransportRequestOptions): TransportRequestPromise<ApiResponse<TResponse, TContext>>;
+  request<TResponse = Record<string, any>, TContext = Context>(params: TransportRequestParams, options?: TransportRequestOptions, callback?: (err: ApiError, result: ApiResponse<TResponse, TContext>) => void): TransportRequestCallback;
   getConnection(opts: TransportGetConnectionOptions): Connection | null;
   sniff(opts?: TransportSniffOptions, callback?: (...args: any[]) => void): void;
 }

lib/Transport.js

@@ -237,6 +237,7 @@ class Transport {
 
       const contentEncoding = (result.headers['content-encoding'] || '').toLowerCase()
       const isCompressed = contentEncoding.indexOf('gzip') > -1 || contentEncoding.indexOf('deflate') > -1
+      const isVectorTile = (result.headers['content-type'] || '').indexOf('application/vnd.mapbox-vector-tile') > -1
 
       /* istanbul ignore else */
       if (result.headers['content-length'] !== undefined) {
@@ -255,8 +256,9 @@ class Transport {
       }
       // if the response is compressed, we must handle it
       // as buffer for allowing decompression later
-      let payload = isCompressed ? [] : ''
-      const onData = isCompressed
+      // while if it's a vector tile, we should return it as buffer
+      let payload = isCompressed || isVectorTile ? [] : ''
+      const onData = isCompressed || isVectorTile
         ? chunk => { payload.push(chunk) }
         : chunk => { payload += chunk }
       const onEnd = err => {
@@ -272,7 +274,7 @@ class Transport {
         if (isCompressed) {
           unzip(Buffer.concat(payload), onBody)
         } else {
-          onBody(null, payload)
+          onBody(null, isVectorTile ? Buffer.concat(payload) : payload)
         }
       }
 
@@ -281,7 +283,7 @@ class Transport {
         onEnd(new Error('Response aborted while reading the body'))
       }
 
-      if (!isCompressed) {
+      if (!isCompressed && !isVectorTile) {
         response.setEncoding('utf8')
       }
 
@@ -297,7 +299,9 @@ class Transport {
         this.emit('response', err, result)
         return callback(err, result)
       }
-      if (Buffer.isBuffer(payload)) {
+
+      const isVectorTile = (result.headers['content-type'] || '').indexOf('application/vnd.mapbox-vector-tile') > -1
+      if (Buffer.isBuffer(payload) && !isVectorTile) {
         payload = payload.toString()
       }
       const isHead = params.method === 'HEAD'

test/unit/transport.test.js

@@ -2689,3 +2689,76 @@ test('The callback with a sync error should be called in the next tick - ndjson'
   t.type(transportReturn.catch, 'function')
   t.type(transportReturn.abort, 'function')
 })
+
+test('Support mapbox vector tile', t => {
+  t.plan(2)
+  const mvtContent = 'GoMCCgRtZXRhEikSFAAAAQACAQMBBAAFAgYDBwAIBAkAGAMiDwkAgEAagEAAAP8//z8ADxoOX3NoYXJkcy5mYWlsZWQaD19zaGFyZHMuc2tpcHBlZBoSX3NoYXJkcy5zdWNjZXNzZnVsGg1fc2hhcmRzLnRvdGFsGhlhZ2dyZWdhdGlvbnMuX2NvdW50LmNvdW50GhdhZ2dyZWdhdGlvbnMuX2NvdW50LnN1bRoTaGl0cy50b3RhbC5yZWxhdGlvbhoQaGl0cy50b3RhbC52YWx1ZRoJdGltZWRfb3V0GgR0b29rIgIwACICMAIiCRkAAAAAAAAAACIECgJlcSICOAAogCB4Ag=='
+
+  function handler (req, res) {
+    res.setHeader('Content-Type', 'application/vnd.mapbox-vector-tile')
+    res.end(Buffer.from(mvtContent, 'base64'))
+  }
+
+  buildServer(handler, ({ port }, server) => {
+    const pool = new ConnectionPool({ Connection })
+    pool.addConnection(`http://localhost:${port}`)
+
+    const transport = new Transport({
+      emit: () => {},
+      connectionPool: pool,
+      serializer: new Serializer(),
+      maxRetries: 3,
+      requestTimeout: 30000,
+      sniffInterval: false,
+      sniffOnStart: false
+    })
+    skipProductCheck(transport)
+
+    transport.request({
+      method: 'GET',
+      path: '/hello'
+    }, (err, { body }) => {
+      t.error(err)
+      t.same(body.toString('base64'), Buffer.from(mvtContent, 'base64').toString('base64'))
+      server.stop()
+    })
+  })
+})
+
+test('Compressed mapbox vector tile', t => {
+  t.plan(2)
+  const mvtContent = 'GoMCCgRtZXRhEikSFAAAAQACAQMBBAAFAgYDBwAIBAkAGAMiDwkAgEAagEAAAP8//z8ADxoOX3NoYXJkcy5mYWlsZWQaD19zaGFyZHMuc2tpcHBlZBoSX3NoYXJkcy5zdWNjZXNzZnVsGg1fc2hhcmRzLnRvdGFsGhlhZ2dyZWdhdGlvbnMuX2NvdW50LmNvdW50GhdhZ2dyZWdhdGlvbnMuX2NvdW50LnN1bRoTaGl0cy50b3RhbC5yZWxhdGlvbhoQaGl0cy50b3RhbC52YWx1ZRoJdGltZWRfb3V0GgR0b29rIgIwACICMAIiCRkAAAAAAAAAACIECgJlcSICOAAogCB4Ag=='
+
+  function handler (req, res) {
+    const body = gzipSync(Buffer.from(mvtContent, 'base64'))
+    res.setHeader('Content-Type', 'application/vnd.mapbox-vector-tile')
+    res.setHeader('Content-Encoding', 'gzip')
+    res.setHeader('Content-Length', Buffer.byteLength(body))
+    res.end(body)
+  }
+
+  buildServer(handler, ({ port }, server) => {
+    const pool = new ConnectionPool({ Connection })
+    pool.addConnection(`http://localhost:${port}`)
+
+    const transport = new Transport({
+      emit: () => {},
+      connectionPool: pool,
+      serializer: new Serializer(),
+      maxRetries: 3,
+      requestTimeout: 30000,
+      sniffInterval: false,
+      sniffOnStart: false
+    })
+    skipProductCheck(transport)
+
+    transport.request({
+      method: 'GET',
+      path: '/hello'
+    }, (err, { body }) => {
+      t.error(err)
+      t.same(body.toString('base64'), Buffer.from(mvtContent, 'base64').toString('base64'))
+      server.stop()
+    })
+  })
+})