feat: pass the request method to beforeRedirect

README.md

@@ -63,12 +63,14 @@ const { http, https } = require('follow-redirects');
 
 const options = url.parse('http://bit.ly/900913');
 options.maxRedirects = 10;
-options.beforeRedirect = (options, { headers, statusCode, requestUrl }) => {
+options.beforeRedirect = (options, { headers, statusCode, requestMethod, requestUrl }) => {
   // Use this to adjust the request options upon redirecting,
   // to inspect the latest response headers,
   // or to cancel the request by throwing an error
+
   // headers = the redirect response headers
   // statusCode = the redirect response code (eg. 301, 307, etc.)
+  // requestMethod = the request method that resulted in a redirect
   // requestUrl = the requested URL that resulted in a redirect
   if (options.hostname === "example.com") {
     options.auth = "user:password";

index.js

@@ -366,6 +366,7 @@ RedirectableRequest.prototype._processResponse = function (response) {
   // care for methods not known to be safe, […]
   // RFC7231§6.4.2–3: For historical reasons, a user agent MAY change
   // the request method from POST to GET for the subsequent request.
+  var originalRequestMethod = this._options.method;
   if ((statusCode === 301 || statusCode === 302) && this._options.method === "POST" ||
       // RFC7231§6.4.4: The 303 (See Other) status code indicates that
       // the server is redirecting the user agent to a different resource […]
@@ -417,6 +418,7 @@ RedirectableRequest.prototype._processResponse = function (response) {
     var responseDetails = {
       headers: response.headers,
       statusCode: statusCode,
+      requestMethod: originalRequestMethod,
       requestUrl: currentUrl,
     };
     try {

test/test.js

@@ -1613,6 +1613,34 @@ describe("follow-redirects", function () {
         });
     });
 
+    it("passes the request method to beforeRedirect", function () {
+      app.post("/a", redirectsTo("/b", 308));
+      app.post("/b", redirectsTo("/c", 301));
+      app.get("/c", redirectsTo("/d", 301));
+      app.get("/d", sendsJson({ a: "b" }));
+
+      const requestMethods = [];
+
+      return server.start(app)
+        .then(asPromise(function (resolve, reject) {
+          var options = {
+            host: "localhost",
+            port: 3600,
+            path: "/a",
+            method: "POST",
+            beforeRedirect: function (_, response) {
+              requestMethods.push(response.requestMethod);
+            },
+          };
+          http.get(options, concatJson(resolve, reject)).on("error", reject);
+        }))
+        .then(function (res) {
+          assert.deepEqual(res.responseUrl, "http://localhost:3600/d");
+          assert.deepEqual(res.parsedJson, { a: "b" });
+          assert.deepEqual(requestMethods, ["POST", "POST", "GET"]);
+        });
+    });
+
     it("passes the original request URL to beforeRedirect", function () {
       app.get("/a", redirectsTo("/b"));
       app.get("/b", redirectsTo("/c"));