update to 4.0

rule_sample/sample_modify_request_protocol.js

@@ -0,0 +1,20 @@
+/* 
+  sample: 
+    redirect all http requests of httpbin.org to https
+  test:
+    curl 'http://httpbin.org/get?show_env=1' --proxy http://127.0.0.1:8001
+  expected response:
+    { "X-Forwarded-Protocol": "https" }
+*/
+module.exports = {
+  *beforeSendRequest(requestDetail) {
+    if (requestDetail.url.indexOf('http://httpbin.org') === 0) {
+      const newOption = requestDetail.requestOptions;
+      newOption.port = 443;
+      return {
+        protocol: 'https',
+        requestOptions: newOption
+      };
+    }
+  }
+};