Import //fetch from Web Platform Tests.

third_party/WebKit/LayoutTests/external/wpt/fetch/api/request/request-cache.js

+/**
+ * Each test is run twice: once using etag/If-None-Match and once with
+ * date/If-Modified-Since.  Each test run gets its own URL and randomized
+ * content and operates independently.
+ *
+ * The test steps are run with request_cache.length fetch requests issued
+ * and their immediate results sanity-checked.  The cache.py server script
+ * stashes an entry containing any If-None-Match, If-Modified-Since, Pragma,
+ * and Cache-Control observed headers for each request it receives.  When
+ * the test fetches have run, this state is retrieved from cache.py and the
+ * expected_* lists are checked, including their length.
+ *
+ * This means that if a request_* fetch is expected to hit the cache and not
+ * touch the network, then there will be no entry for it in the expect_*
+ * lists.  AKA (request_cache.length - expected_validation_headers.length)
+ * should equal the number of cache hits that didn't touch the network.
+ *
+ * Test dictionary keys:
+ * - state: required string that determines whether the Expires response for
+ *   the fetched document should be set in the future ("fresh") or past
+ *   ("stale").
+ * - vary: optional string to be passed to the server for it to quote back
+ *   in a Vary header on the response to us.
+ * - cache_control: optional string to be passed to the server for it to
+ *   quote back in a Cache-Control header on the response to us.
+ * - redirect: optional string "same-origin" or "cross-origin".  If
+ *   provided, the server will issue an absolute redirect to the script on
+ *   the same or a different origin, as appropriate.  The redirected
+ *   location is the script with the redirect parameter removed, so the
+ *   content/state/etc. will be as if you hadn't specified a redirect.
+ * - request_cache: required array of cache modes to use (via `cache`).
+ * - request_headers: optional array of explicit fetch `headers` arguments.
+ *   If provided, the server will log an empty dictionary for each request
+ *   instead of the request headers it would normally log.
+ * - response: optional array of specialized response handling.  Right now,
+ *   "error" array entries indicate a network error response is expected
+ *   which will reject with a TypeError.
+ * - expected_validation_headers: required boolean array indicating whether
+ *   the server should have seen an If-None-Match/If-Modified-Since header
+ *   in the request.
+ * - expected_no_cache_headers: required boolean array indicating whether
+ *   the server should have seen Pragma/Cache-control:no-cache headers in
+ *   the request.
+ * - expected_max_age_headers: optional boolean array indicating whether
+ *   the server should have seen a Cache-Control:max-age=0 header in the
+ *   request.
+ */
+
+var now = new Date();
+
+function base_path() {
+  return location.pathname.replace(/\/[^\/]*$/, '/');
+}
+function make_url(uuid, id, value, content, info) {
+  var dates = {
+    fresh: new Date(now.getFullYear() + 1, now.getMonth(), now.getDay()).toGMTString(),
+    stale: new Date(now.getFullYear() - 1, now.getMonth(), now.getDay()).toGMTString(),
+  };
+  var vary = "";
+  if ("vary" in info) {
+    vary = "&vary=" + info.vary;
+  }
+  var cache_control = "";
+  if ("cache_control" in info) {
+    cache_control = "&cache_control=" + info.cache_control;
+  }
+  var redirect = "";
+
+  var ignore_request_headers = "";
+  if ("request_headers" in info) {
+    // Ignore the request headers that we send since they may be synthesized by the test.
+    ignore_request_headers = "&ignore";
+  }
+  var url_sans_redirect = "resources/cache.py?token=" + uuid +
+    "&content=" + content +
+    "&" + id + "=" + value +
+    "&expires=" + dates[info.state] +
+    vary + cache_control + ignore_request_headers;
+  // If there's a redirect, the target is the script without any redirect at
+  // either the same domain or a different domain.
+  if ("redirect" in info) {
+    var host_info = get_host_info();
+    var origin;
+    switch (info.redirect) {
+      case "same-origin":
+        origin = host_info['HTTP_ORIGIN'];
+        break;
+      case "cross-origin":
+        origin = host_info['HTTP_REMOTE_ORIGIN'];
+        break;
+    }
+    var redirected_url = origin + base_path() + url_sans_redirect;
+    return url_sans_redirect + "&redirect=" + encodeURIComponent(redirected_url);
+  } else {
+    return url_sans_redirect;
+  }
+}
+function expected_status(type, identifier, init) {
+  if (type == "date" &&
+      init.headers &&
+      init.headers["If-Modified-Since"] == identifier) {
+    // The server will respond with a 304 in this case.
+    return [304, "Not Modified"];
+  }
+  return [200, "OK"];
+}
+function expected_response_text(type, identifier, init, content) {
+  if (type == "date" &&
+      init.headers &&
+      init.headers["If-Modified-Since"] == identifier) {
+    // The server will respond with a 304 in this case.
+    return "";
+  }
+  return content;
+}
+function server_state(uuid) {
+  return fetch("resources/cache.py?querystate&token=" + uuid)
+    .then(function(response) {
+      return response.text();
+    }).then(function(text) {
+      // null will be returned if the server never received any requests
+      // for the given uuid.  Normalize that to an empty list consistent
+      // with our representation.
+      return JSON.parse(text) || [];
+    });
+}
+function make_test(type, info) {
+  return function(test) {
+    var uuid = token();
+    var identifier = (type == "tag" ? Math.random() : now.toGMTString());
+    var content = Math.random().toString();
+    var url = make_url(uuid, type, identifier, content, info);
+    var fetch_functions = [];
+    for (var i = 0; i < info.request_cache.length; ++i) {
+      fetch_functions.push(function(idx) {
+        var init = {cache: info.request_cache[idx]};
+        if ("request_headers" in info) {
+          init.headers = info.request_headers[idx];
+        }
+        if (init.cache === "only-if-cached") {
+          // only-if-cached requires we use same-origin mode.
+          init.mode = "same-origin";
+        }
+        return fetch(url, init)
+          .then(function(response) {
+            if ("response" in info && info.response[idx] === "error") {
+              assert_true(false, "fetch should have been an error");
+              return;
+            }
+            assert_array_equals([response.status, response.statusText],
+                                expected_status(type, identifier, init));
+            return response.text();
+          }).then(function(text) {
+            assert_equals(text, expected_response_text(type, identifier, init, content));
+          }, function(reason) {
+            if ("response" in info && info.response[idx] === "error") {
+              assert_throws(new TypeError(), function() { throw reason; });
+            } else {
+              throw reason;
+            }
+          });
+      });
+    }
+    var i = 0;
+    function run_next_step() {
+      if (fetch_functions.length) {
+        return fetch_functions.shift()(i++)
+          .then(run_next_step);
+      } else {
+        return Promise.resolve();
+      }
+    }
+    return run_next_step()
+      .then(function() {
+        // Now, query the server state
+        return server_state(uuid);
+      }).then(function(state) {
+        var expectedState = [];
+        info.expected_validation_headers.forEach(function (validate) {
+          if (validate) {
+            if (type == "tag") {
+              expectedState.push({"If-None-Match": '"' + identifier + '"'});
+            } else {
+              expectedState.push({"If-Modified-Since": identifier});
+            }
+          } else {
+            expectedState.push({});
+          }
+        });
+        for (var i = 0; i < info.expected_no_cache_headers.length; ++i) {
+          if (info.expected_no_cache_headers[i]) {
+            expectedState[i]["Pragma"] = "no-cache";
+            expectedState[i]["Cache-Control"] = "no-cache";
+          }
+        }
+        if ("expected_max_age_headers" in info) {
+          for (var i = 0; i < info.expected_max_age_headers.length; ++i) {
+            if (info.expected_max_age_headers[i]) {
+              expectedState[i]["Cache-Control"] = "max-age=0";
+            }
+          }
+        }
+        assert_equals(state.length, expectedState.length);
+        for (var i = 0; i < state.length; ++i) {
+          for (var header in state[i]) {
+            assert_equals(state[i][header], expectedState[i][header]);
+            delete expectedState[i][header];
+          }
+          for (var header in expectedState[i]) {
+            assert_false(header in state[i]);
+          }
+        }
+      });
+  };
+}
+
+function run_tests(tests)
+{
+  tests.forEach(function(info) {
+    promise_test(make_test("tag", info), info.name + " with Etag and " + info.state + " response");
+    promise_test(make_test("date", info), info.name + " with Last-Modified and " + info.state + " response");
+  });
+}