1 files changed, 23 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/type-argument-plaintext.window.js b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/type-argument-plaintext.window.js
new file mode 100644
index 0000000000..ab1d9706a4
--- /dev/null
+++ b/testing/web-platform/tests/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/type-argument-plaintext.window.js
@@ -0,0 +1,23 @@
+["replace",
+ "NOBODY",
+ "@ FD ;",
+ "it does not matter, you see \f",
+ "text/plain",
+ "text/xml",
+ "application/octet-stream",
+ "\0"].forEach(type => {
+  async_test(t => {
+    const frame = document.createElement("iframe");
+    frame.src = "type-argument-plaintext-subframe.txt";
+    document.body.appendChild(frame);
+    t.add_cleanup(() => frame.remove());
+    frame.onload = t.step_func_done(() => {
+      assert_equals(frame.contentDocument.open(type), frame.contentDocument);
+      frame.contentDocument.write("<B>heya</b>");
+      frame.contentDocument.close();
+      assert_equals(frame.contentDocument.body.firstChild.localName, "b");
+      assert_equals(frame.contentDocument.body.textContent, "heya");
+      assert_equals(frame.contentDocument.contentType, "text/plain");
+    });
+  }, "document.open() on plaintext document with type set to: " + type + " (type argument is supposed to be ignored)");
+});