Set encoding according to content-type charset

lib/client.js

@@ -9,6 +9,7 @@ const debug = require('debug')('api-gateway');
 
 const ua = require('./ua');
 const Base = require('./base');
+const { fetchPropertyFromHeader } = require('./util');
 
 const form = 'application/x-www-form-urlencoded';
 const hasOwnProperty = function (obj, key) {
@@ -191,8 +192,9 @@ class Client extends Base {
       throw err;
     }
 
-    var result = await httpx.read(response, 'utf8');
     var contentType = response.headers['content-type'] || '';
+    const charset = fetchPropertyFromHeader(contentType, 'charset') || 'utf8';
+    var result = await httpx.read(response, charset);
     if (contentType.startsWith('application/json')) {
       result = JSON.parse(result);
     }

lib/util.js

@@ -0,0 +1,19 @@
+'use strict';
+
+function fetchPropertyFromHeader(headerStr, key) {
+  const values = headerStr.split(';') || [];
+  let result;
+  values.some((pair) => {
+    const kv = pair.trim().split('=');
+    if(kv.length === 2 && kv[0] === key) {
+      result = kv[1];
+      return true;
+    }
+    return false;
+  });
+  return result;
+}
+
+module.exports = {
+  fetchPropertyFromHeader
+};

test/util.test.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const expect = require('expect.js');
+const { fetchPropertyFromHeader } = require('../lib/util');
+
+describe('util', function () {
+  it('should be target charset', async function () {
+    expect('binary').to.be.eql(fetchPropertyFromHeader('application/json; charset=binary', 'charset'));
+    expect(undefined).to.be.eql(fetchPropertyFromHeader('application/json;', 'charset'));
+    expect('utf-8').to.be.eql(fetchPropertyFromHeader('application/json;charset=utf-8;', 'charset'));
+  });
+});