add support for getSetCookie() method on fetch response headers objects.

Fixes #56
Relates to whatwg/fetch#1346

README.md

@@ -6,15 +6,15 @@
 
 Parses set-cookie headers into objects
 
-Accepts a single `set-cookie` header value, an array of `set-cookie` header values, or a Node.js response object that may have 0 or more `set-cookie` headers.
+Accepts a single `set-cookie` header value, an array of `set-cookie` header values, a Node.js response object, or a `fetch()` `Response` object that may have 0 or more `set-cookie` headers.
 
 Also accepts an optional options object. Defaults:
 
 ```js
 {
-    decodeValues: true,  // Calls dcodeURIComponent on each value - default: true
+    decodeValues: true,  // Calls decodeURIComponent on each value - default: true
     map: false,          // Return an object instead of an array - default: false
-    silent: false,       // Suppress the warning that is loged when called on a request instead of a response - default: false
+    silent: false,       // Suppress the warning that is logged when called on a request instead of a response - default: false
 }
 ```
 
@@ -26,7 +26,7 @@ Returns either an array of cookie objects or a map of name => cookie object with
 * `domain` - domain for the cookie (string or undefined, may begin with "." to indicate the named domain or any subdomain of it)
 * `expires` - absolute expiration date for the cookie (Date object or undefined)
 * `maxAge` - relative max age of the cookie in seconds from when the client receives it (integer or undefined)
-  * Note: when using with [express's res.cookie() method](http://expressjs.com/en/4x/api.html#res.cookie), multiply `maxAge` by 1000 to convert to miliseconds.
+  * Note: when using with [express's res.cookie() method](http://expressjs.com/en/4x/api.html#res.cookie), multiply `maxAge` by 1000 to convert to milliseconds.
 * `secure` - indicates that this cookie should only be sent over HTTPs (true or undefined)
 * `httpOnly` - indicates that this cookie should *not* be accessible to client-side JavaScript (true or undefined)
 * `sameSite` - indicates a cookie ought not to be sent along with cross-site requests (string or undefined)
@@ -140,9 +140,9 @@ function modifySetCookie(res){
 
 See a real-world example of this in [unblocker](https://github.com/nfriedly/node-unblocker/blob/08a89ec27274b46dcd80d0a324a59406f2bdad3d/lib/cookies.js#L67-L85)
 
-## Usage in React Native
+## Usage in React Native (and with some other fetch implementations)
 
-React Native follows the Fetch spec more closely and combines all of the Set-Cookie header values into a single string. 
+React Native follows the Fetch spec more closely and combines all of the Set-Cookie header values into a single string.
 The `splitCookiesString` method reverses this.
 
 ```js
@@ -160,6 +160,8 @@ console.log(cookies); // should be an array of cookies
 
 This behavior may become a default part of parse in the next major release, but requires the extra step for now.
 
+Note that the `fetch()` spec now includes a `getSetCookie()` method that provides un-combined `Set-Cookie` headers. This library will automatically use that method if it is present.
+
 ## API
 
 ### parse(input, [options])

lib/set-cookie.js

@@ -89,24 +89,30 @@ function parse(input, options) {
     }
   }
 
-  if (input.headers && input.headers["set-cookie"]) {
-    // fast-path for node.js (which automatically normalizes header names to lower-case
-    input = input.headers["set-cookie"];
-  } else if (input.headers) {
-    // slow-path for other environments - see #25
-    var sch =
-      input.headers[
-        Object.keys(input.headers).find(function (key) {
-          return key.toLowerCase() === "set-cookie";
-        })
-      ];
-    // warn if called on a request-like object with a cookie header rather than a set-cookie header - see #34, 36
-    if (!sch && input.headers.cookie && !options.silent) {
-      console.warn(
-        "Warning: set-cookie-parser appears to have been called on a request object. It is designed to parse Set-Cookie headers from responses, not Cookie headers from requests. Set the option {silent: true} to suppress this warning."
-      );
+  if (input.headers) {
+    if (typeof input.headers.getSetCookie === "function") {
+      // for fetch responses - they combine headers of the same type in the headers array,
+      // but getSetCookie returns an uncombined array
+      input = input.headers.getSetCookie();
+    } else if (input.headers["set-cookie"]) {
+      // fast-path for node.js (which automatically normalizes header names to lower-case
+      input = input.headers["set-cookie"];
+    } else {
+      // slow-path for other environments - see #25
+      var sch =
+        input.headers[
+          Object.keys(input.headers).find(function (key) {
+            return key.toLowerCase() === "set-cookie";
+          })
+        ];
+      // warn if called on a request-like object with a cookie header rather than a set-cookie header - see #34, 36
+      if (!sch && input.headers.cookie && !options.silent) {
+        console.warn(
+          "Warning: set-cookie-parser appears to have been called on a request object. It is designed to parse Set-Cookie headers from responses, not Cookie headers from requests. Set the option {silent: true} to suppress this warning."
+        );
+      }
+      input = sch;
     }
-    input = sch;
   }
   if (!Array.isArray(input)) {
     input = [input];

test/fetch.js

@@ -0,0 +1,28 @@
+"use strict";
+var assert = require("assert");
+var setCookie = require("../lib/set-cookie.js");
+
+describe("fetch", () => {
+  before(() => {
+    // conditionall skip these tests if the environment doesn't support the necessary features
+    if (
+      typeof fetch !== "undefined" &&
+      typeof Response !== "undefined" &&
+      typeof new Response().headers.getSetCookie !== "function"
+    ) {
+      this.skip();
+    }
+  });
+
+  it("should use getSetCookie method on a Response object", () => {
+    const fakeResponse = {
+      headers: {
+        getSetCookie: () => ["foo=bar"],
+      },
+    };
+
+    var actual = setCookie.parse(fakeResponse);
+    var expected = [{ name: "foo", value: "bar" }];
+    assert.deepEqual(actual, expected);
+  });
+});