Fetch: the Set-Cookie header, and Header's getSetCookie()

For whatwg/fetch#1346.

Co-authored-by: Andreu Botella <abotella@igalia.com>
Co-authored-by: Andreu Botella <andreu@andreubotella.com>
Co-authored-by: Anne van Kesteren <annevk@annevk.nl>

fetch/api/headers/header-setcookie.any.js

@@ -0,0 +1,224 @@
+// META: title=Headers set-cookie special cases
+// META: global=window,worker
+
+const headerList = [
+  ["set-cookie", "foo=bar"],
+  ["Set-Cookie", "fizz=buzz; domain=example.com"],
+];
+
+const setCookie2HeaderList = [
+  ["set-cookie2", "foo2=bar2"],
+  ["Set-Cookie2", "fizz2=buzz2; domain=example2.com"],
+];
+
+function assert_nested_array_equals(actual, expected) {
+  assert_equals(actual.length, expected.length, "Array length is not equal");
+  for (let i = 0; i < expected.length; i++) {
+    assert_array_equals(actual[i], expected[i]);
+  }
+}
+
+test(function () {
+  const headers = new Headers(headerList);
+  assert_equals(
+    headers.get("set-cookie"),
+    "foo=bar, fizz=buzz; domain=example.com",
+  );
+}, "Headers.prototype.get combines set-cookie headers in order");
+
+test(function () {
+  const headers = new Headers(headerList);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo=bar"],
+    ["set-cookie", "fizz=buzz; domain=example.com"],
+  ]);
+}, "Headers iterator does not combine set-cookie headers");
+
+test(function () {
+  const headers = new Headers(setCookie2HeaderList);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie2", "foo2=bar2, fizz2=buzz2; domain=example2.com"],
+  ]);
+}, "Headers iterator does not special case set-cookie2 headers");
+
+test(function () {
+  const headers = new Headers([...headerList, ...setCookie2HeaderList]);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo=bar"],
+    ["set-cookie", "fizz=buzz; domain=example.com"],
+    ["set-cookie2", "foo2=bar2, fizz2=buzz2; domain=example2.com"],
+  ]);
+}, "Headers iterator does not combine set-cookie & set-cookie2 headers");
+
+test(function () {
+  // Values are in non alphabetic order, and the iterator should yield in the
+  // headers in the exact order of the input.
+  const headers = new Headers([
+    ["set-cookie", "z=z"],
+    ["set-cookie", "a=a"],
+    ["set-cookie", "n=n"],
+  ]);
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "z=z"],
+    ["set-cookie", "a=a"],
+    ["set-cookie", "n=n"],
+  ]);
+}, "Headers iterator preserves set-cookie ordering");
+
+test(
+  function () {
+    const headers = new Headers([
+      ["xylophone-header", "1"],
+      ["best-header", "2"],
+      ["set-cookie", "3"],
+      ["a-cool-header", "4"],
+      ["set-cookie", "5"],
+      ["a-cool-header", "6"],
+      ["best-header", "7"],
+    ]);
+    const list = [...headers];
+    assert_nested_array_equals(list, [
+      ["a-cool-header", "4, 6"],
+      ["best-header", "2, 7"],
+      ["set-cookie", "3"],
+      ["set-cookie", "5"],
+      ["xylophone-header", "1"],
+    ]);
+  },
+  "Headers iterator preserves per header ordering, but sorts keys alphabetically",
+);
+
+test(
+  function () {
+    const headers = new Headers([
+      ["xylophone-header", "7"],
+      ["best-header", "6"],
+      ["set-cookie", "5"],
+      ["a-cool-header", "4"],
+      ["set-cookie", "3"],
+      ["a-cool-header", "2"],
+      ["best-header", "1"],
+    ]);
+    const list = [...headers];
+    assert_nested_array_equals(list, [
+      ["a-cool-header", "4, 2"],
+      ["best-header", "6, 1"],
+      ["set-cookie", "5"],
+      ["set-cookie", "3"],
+      ["xylophone-header", "7"],
+    ]);
+  },
+  "Headers iterator preserves per header ordering, but sorts keys alphabetically (and ignores value ordering)",
+);
+
+test(function () {
+  const headers = new Headers([["fizz", "buzz"], ["X-Header", "test"]]);
+  const iterator = headers[Symbol.iterator]();
+  assert_array_equals(iterator.next().value, ["fizz", "buzz"]);
+  headers.append("Set-Cookie", "a=b");
+  assert_array_equals(iterator.next().value, ["set-cookie", "a=b"]);
+  headers.append("Accept", "text/html");
+  assert_array_equals(iterator.next().value, ["set-cookie", "a=b"]);
+  assert_array_equals(iterator.next().value, ["x-header", "test"]);
+  headers.append("set-cookie", "c=d");
+  assert_array_equals(iterator.next().value, ["x-header", "test"]);
+  assert_true(iterator.next().done);
+}, "Headers iterator is correctly updated with set-cookie changes");
+
+test(function () {
+  const headers = new Headers(headerList);
+  assert_true(headers.has("sEt-cOoKiE"));
+}, "Headers.prototype.has works for set-cookie");
+
+test(function () {
+  const headers = new Headers(setCookie2HeaderList);
+  headers.append("set-Cookie", "foo=bar");
+  headers.append("sEt-cOoKiE", "fizz=buzz");
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo=bar"],
+    ["set-cookie", "fizz=buzz"],
+    ["set-cookie2", "foo2=bar2, fizz2=buzz2; domain=example2.com"],
+  ]);
+}, "Headers.prototype.append works for set-cookie");
+
+test(function () {
+  const headers = new Headers(headerList);
+  headers.set("set-cookie", "foo2=bar2");
+  const list = [...headers];
+  assert_nested_array_equals(list, [
+    ["set-cookie", "foo2=bar2"],
+  ]);
+}, "Headers.prototype.set works for set-cookie");
+
+test(function () {
+  const headers = new Headers(headerList);
+  headers.delete("set-Cookie");
+  const list = [...headers];
+  assert_nested_array_equals(list, []);
+}, "Headers.prototype.delete works for set-cookie");
+
+test(function () {
+  const headers = new Headers();
+  assert_array_equals(headers.getSetCookie(), []);
+}, "Headers.prototype.getSetCookie with no headers present");
+
+test(function () {
+  const headers = new Headers([headerList[0]]);
+  assert_array_equals(headers.getSetCookie(), ["foo=bar"]);
+}, "Headers.prototype.getSetCookie with one header");
+
+test(function () {
+  const headers = new Headers({ "Set-Cookie": "foo=bar" });
+  assert_array_equals(headers.getSetCookie(), ["foo=bar"]);
+}, "Headers.prototype.getSetCookie with one header created from an object");
+
+test(function () {
+  const headers = new Headers(headerList);
+  assert_array_equals(headers.getSetCookie(), [
+    "foo=bar",
+    "fizz=buzz; domain=example.com",
+  ]);
+}, "Headers.prototype.getSetCookie with multiple headers");
+
+test(function () {
+  const headers = new Headers([["set-cookie", ""]]);
+  assert_array_equals(headers.getSetCookie(), [""]);
+}, "Headers.prototype.getSetCookie with an empty header");
+
+test(function () {
+  const headers = new Headers([["set-cookie", "x"], ["set-cookie", "x"]]);
+  assert_array_equals(headers.getSetCookie(), ["x", "x"]);
+}, "Headers.prototype.getSetCookie with two equal headers");
+
+test(function () {
+  const headers = new Headers([
+    ["set-cookie2", "x"],
+    ["set-cookie", "y"],
+    ["set-cookie2", "z"],
+  ]);
+  assert_array_equals(headers.getSetCookie(), ["y"]);
+}, "Headers.prototype.getSetCookie ignores set-cookie2 headers");
+
+test(function () {
+  // Values are in non alphabetic order, and the iterator should yield in the
+  // headers in the exact order of the input.
+  const headers = new Headers([
+    ["set-cookie", "z=z"],
+    ["set-cookie", "a=a"],
+    ["set-cookie", "n=n"],
+  ]);
+  assert_array_equals(headers.getSetCookie(), ["z=z", "a=a", "n=n"]);
+}, "Headers.prototype.getSetCookie preserves header ordering");
+
+test(function () {
+  const response = new Response();
+  response.headers.append("Set-Cookie", "foo=bar");
+  assert_array_equals(response.headers.getSetCookie(), []);
+  response.headers.append("sEt-cOokIe", "bar=baz");
+  assert_array_equals(response.headers.getSetCookie(), []);
+}, "Set-Cookie is a forbidden response header");