avoid named export for compatibility below node 10

CHANGELOG.md

@@ -7,7 +7,7 @@ Changelog
 
 ## master
 
-- Fix: `import` on index.js, where `PassThrough` doesn't have a named export when using with node <10 and `--exerimental-modules` flag.
+- Fix: multiple `import` rules, where `PassThrough` etc. doesn't have a named export when using node <10 and `--exerimental-modules` flag.
 
 ## v2.2.0
 

src/body.js

@@ -5,7 +5,8 @@
  * Body interface provides common methods for Request and Response
  */
 
-import Stream, { PassThrough } from 'stream';
+import Stream from 'stream';
+
 import Blob, { BUFFER } from './blob.js';
 import FetchError from './fetch-error.js';
 
@@ -14,6 +15,9 @@ try { convert = require('encoding').convert; } catch(e) {}
 
 const INTERNALS = Symbol('Body internals');
 
+// fix an issue where "PassThrough" isn't a named export for node <10
+const PassThrough = Stream.PassThrough;
+
 /**
  * Body mixin
  *

src/index.js

@@ -7,7 +7,7 @@
  * All spec algorithm step numbers are based on https://fetch.spec.whatwg.org/commit-snapshots/ae716822cb3a61843226cd090eefc6589446c1d2/.
  */
 
-import { resolve as resolve_url } from 'url';
+import Url from 'url';
 import http from 'http';
 import https from 'https';
 import zlib from 'zlib';
@@ -19,8 +19,9 @@ import Headers, { createHeadersLenient } from './headers';
 import Request, { getNodeRequestOptions } from './request';
 import FetchError from './fetch-error';
 
-// fix an issue where PassThrough isn't a named export for node <10
+// fix an issue where "PassThrough", "resolve" aren't a named export for node <10
 const PassThrough = Stream.PassThrough;
+const resolve_url = Url.resolve;
 
 /**
  * Fetch function

src/request.js

@@ -7,12 +7,17 @@
  * All spec algorithm step numbers are based on https://fetch.spec.whatwg.org/commit-snapshots/ae716822cb3a61843226cd090eefc6589446c1d2/.
  */
 
-import { format as format_url, parse as parse_url } from 'url';
+import Url from 'url';
+
 import Headers, { exportNodeCompatibleHeaders } from './headers.js';
 import Body, { clone, extractContentType, getTotalBytes } from './body';
 
 const INTERNALS = Symbol('Request internals');
 
+// fix an issue where "format", "parse" aren't a named export for node <10
+const parse_url = Url.parse;
+const format_url = Url.format;
+
 /**
  * Check if a value is an instance of Request.
  *

src/response.js

@@ -5,12 +5,16 @@
  * Response class provides content decoding
  */
 
-import { STATUS_CODES } from 'http';
+import http from 'http';
+
 import Headers from './headers.js';
 import Body, { clone } from './body';
 
 const INTERNALS = Symbol('Response internals');
 
+// fix an issue where "STATUS_CODES" aren't a named export for node <10
+const STATUS_CODES = http.STATUS_CODES;
+
 /**
  * Response class
  *