Test that History is associated with Document, not Window

common/object-association.js

@@ -1,26 +1,24 @@
 "use strict";
 
-// For now this only has per-Window tests, but we could expand it to also test per-Document
+// This is for testing whether an object (e.g., a global property) is associated with Window, or
+// with Document. Recall that Window and Document are 1:1 except when doing a same-origin navigation
+// away from the initial about:blank. In that case the Window object gets reused for the new
+// Document.
+//
+// So:
+// - If something is per-Window, then it should maintain its identity across an about:blank
+// navigation.
+// - If something is per-Document, then it should be recreated across an about:blank navigation.
 
-/**
- * Run tests for window[propertyName] after discarding the browsing context, navigating, etc.
- * @param {string} propertyName
- */
 window.testIsPerWindow = propertyName => {
- test(t => {
- const iframe = document.createElement("iframe");
- document.body.appendChild(iframe);
- const frame = iframe.contentWindow;
-
- const before = frame[propertyName];
- assert_true(before !== undefined && before !== null, `window.${propertyName} must be implemented`);
-
- iframe.remove();
+ runTests(propertyName, assert_equals, "must not");
+};
 
- const after = frame[propertyName];
-  assert_equals(after, before, `window.${propertyName} should not change after iframe.remove()`);
- }, `Discarding the browsing context must not change window.${propertyName}`);
+window.testIsPerDocument = propertyName => {
+ runTests(propertyName, assert_not_equals, "must");
+};
 
+function runTests(propertyName, equalityOrInequalityAsserter, mustOrMustNotReplace) {
  async_test(t => {
  const iframe = document.createElement("iframe");
  document.body.appendChild(iframe);
@@ -38,14 +36,30 @@ window.testIsPerWindow = propertyName => {
  }
 
  const after = frame[propertyName];
- assert_equals(after, before);
+ equalityOrInequalityAsserter(after, before);
  t.done();
  });
 
  iframe.src = "/common/blank.html";
- }, `Navigating from the initial about:blank must not replace window.${propertyName}`);
+ }, `Navigating from the initial about:blank ${mustOrMustNotReplace} replace window.${propertyName}`);
 
- // Per spec, document.open() should not change any of the Window state.
+ // Per spec, discarding a browsing context should not change any of the global objects.
+ test(() => {
+ const iframe = document.createElement("iframe");
+ document.body.appendChild(iframe);
+ const frame = iframe.contentWindow;
+
+ const before = frame[propertyName];
+ assert_true(before !== undefined && before !== null, `window.${propertyName} must be implemented`);
+
+ iframe.remove();
+
+ const after = frame[propertyName];
+ assert_equals(after, before, `window.${propertyName} should not change after iframe.remove()`);
+ }, `Discarding the browsing context must not change window.${propertyName}`);
+
+ // Per spec, document.open() should not change any of the global objects. In historical versions
+ // of the spec, it did, so we test here.
  async_test(t => {
  const iframe = document.createElement("iframe");
 
@@ -64,5 +78,5 @@ window.testIsPerWindow = propertyName => {
 
  iframe.src = "/common/blank.html";
  document.body.appendChild(iframe);
- }, `document.open() must replace window.${propertyName}`);
-};
+ }, `document.open() must not replace window.${propertyName}`);
+}

html/browsers/history/the-history-interface/history-associated-with-document.window.js

@@ -0,0 +1,6 @@
+// META: title=the History object must be associated with the Document object, not the Window object
+// META: script=/common/object-association.js
+
+// See https:/whatwg/html/issues/2566.
+
+testIsPerDocument("history");