Bug 1564707 [wpt PR 17439] - Add manual test for print(), a=testonly

Automatic update from web-platform-tests Add manual test for print() For https://github.com/whatwg/html/pull/4690. -- wpt-commits: 8e53d2a89fe610b2ce480877c60bca88c949cf60 wpt-pr: 17439
2019-07-19 19:40:16 +00:00 · 2019-07-19 19:40:16 +00:00 · 99978cbdd5
--- a/testing/web-platform/tests/html/webappapis/user-prompts/print-manual.html
+++ b/testing/web-platform/tests/html/webappapis/user-prompts/print-manual.html
@ -0,0 +1,93 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Printing</title>
+<link rel=help href="https://html.spec.whatwg.org/#printing">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+setup({explicit_timeout: true})
+</script>
+
+<p>Click on the button below.</p>
+<p>If the browser offers to print the current page, dismiss the prompt to
+return to this page. The following should then appear in the box marked as
+"Output":</p>
+<pre>
+before calling print()
+beforeprint
+afterprint
+after calling print()
+</pre>
+<p>If no user dialog appears, either the above or the following should be
+printed in the box marked as "Output":</p>
+<pre>
+before calling print()
+after calling print()
+</pre>
+<p>The test passes if the above criteria are satisfied and "PASS" appears in a
+table below this paragraph. The test fails otherwise.</p>
+
+<button onclick="testBtn(this)">Click here!</button>
+<h3>Output</h3>
+<pre id=output></pre>
+
+<script>
+"use strict";
+// This test is actually synchronous, but we use async_test()'s nice
+// infrastructure around t.step() to capture errors in event listeners. This is
+// necessary since it seems like in Chrome, exceptions in beforeprint/afterprint
+// event listeners are not propagated to error events. See
+// https://crbug.com/977828.
+const t = async_test();
+const log = [];
+function out(str) {
+  log.push(str);
+  output.appendChild(document.createTextNode(str + "\n"));
+}
+function testBtn(btn) {
+  btn.remove();
+  window.addEventListener("beforeprint", function (ev) {
+    // t.step_func() does not preserve `this`, which we test below.
+    t.step(() => {
+      out("beforeprint");
+      assert_equals(ev.__proto__, Event.prototype);
+      assert_equals(this, window);
+      assert_equals(ev.target, window);
+      assert_equals(ev.type, "beforeprint");
+    });
+  });
+  window.addEventListener("afterprint", function (ev) {
+    // t.step_func() does not preserve `this`, which we test below.
+    t.step(() => {
+      out("afterprint");
+      assert_equals(ev.__proto__, Event.prototype);
+      assert_equals(this, window);
+      assert_equals(ev.target, window);
+      assert_equals(ev.type, "afterprint");
+    });
+  });
+  out("before calling print()");
+  print();
+  out("after calling print()");
+  t.step(() => {
+    try {
+      assert_array_equals(log, [
+        "before calling print()",
+        "beforeprint",
+        "afterprint",
+        "after calling print()",
+      ]);
+    } catch (err) {
+      try {
+        assert_array_equals(log, [
+          "before calling print()",
+          "after calling print()",
+        ]);
+      } catch (err) {
+        assert_unreached("Output does not match either possibility");
+      }
+    }
+  });
+  t.done();
+}
+</script>