1 files changed, 130 insertions, 0 deletions
diff --git a/gfx/layers/apz/test/mochitest/helper_fission_utils.js b/gfx/layers/apz/test/mochitest/helper_fission_utils.js
new file mode 100644
index 0000000000..ddcab62253
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+++ b/gfx/layers/apz/test/mochitest/helper_fission_utils.js
@@ -0,0 +1,130 @@
+// loadOOPIFrame expects apz_test_utils.js to be loaded as well, for promiseOneEvent.
+/* import-globals-from apz_test_utils.js */
+
+function fission_subtest_init() {
+  // Silence SimpleTest warning about missing assertions by having it wait
+  // indefinitely. We don't need to give it an explicit finish because the
+  // entire window this test runs in will be closed after subtestDone is called.
+  SimpleTest.waitForExplicitFinish();
+
+  // This is the point at which we inject the ok, is, subtestDone, etc. functions
+  // into this window. In particular this function should run after SimpleTest.js
+  // is imported, otherwise SimpleTest.js will clobber the functions with its
+  // own versions. This is implicitly enforced because if we call this function
+  // before SimpleTest.js is imported, the above line will throw an exception.
+  window.dispatchEvent(new Event("FissionTestHelper:Init"));
+}
+
+/**
+ * Starts loading the given `iframePage` in the iframe element with the given
+ * id, and waits for it to load.
+ * Note that calling this function doesn't do the load directly; instead it
+ * returns an async function which can be added to a thenable chain.
+ */
+function loadOOPIFrame(iframeElementId, iframePage) {
+  return async function () {
+    if (window.location.href.startsWith("https://example.com/")) {
+      dump(
+        `WARNING: Calling loadOOPIFrame from ${window.location.href} so the iframe may not be OOP\n`
+      );
+      ok(false, "Current origin is not example.com:443");
+    }
+
+    let url =
+      "https://example.com/browser/gfx/layers/apz/test/mochitest/" + iframePage;
+    let loadPromise = promiseOneEvent(window, "OOPIF:Load", function (e) {
+      return typeof e.data.content == "string" && e.data.content == url;
+    });
+    let elem = document.getElementById(iframeElementId);
+    elem.src = url;
+    await loadPromise;
+  };
+}
+
+/**
+ * This is similar to the hitTest function in apz_test_utils.js, in that it
+ * does a hit-test for a point and returns the result. The difference is that
+ * in the fission world, the hit-test may land on an OOPIF, which means the
+ * result information will be in the APZ test data for the OOPIF process. This
+ * function checks both the current process and OOPIF process to see which one
+ * got a hit result, and returns the result regardless of which process got it.
+ * The caller is expected to check the layers id which will allow distinguishing
+ * the two cases.
+ */
+async function fissionHitTest(point, iframeElement) {
+  let get_iframe_compositor_test_data = function () {
+    let utils = SpecialPowers.getDOMWindowUtils(window);
+    return JSON.stringify(utils.getCompositorAPZTestData());
+  };
+
+  let utils = SpecialPowers.getDOMWindowUtils(window);
+
+  // Get the test data before doing the actual hit-test, to get a baseline
+  // of what we can ignore.
+  let oldParentTestData = utils.getCompositorAPZTestData();
+  let oldIframeTestData = JSON.parse(
+    await FissionTestHelper.sendToOopif(
+      iframeElement,
+      `(${get_iframe_compositor_test_data})()`
+    )
+  );
+
+  // Now do the hit-test
+  dump(`Hit-testing point (${point.x}, ${point.y}) in fission context\n`);
+  utils.sendMouseEvent(
+    "MozMouseHittest",
+    point.x,
+    point.y,
+    0,
+    0,
+    0,
+    true,
+    0,
+    0,
+    true,
+    true
+  );
+
+  // Collect the new test data
+  let newParentTestData = utils.getCompositorAPZTestData();
+  let newIframeTestData = JSON.parse(
+    await FissionTestHelper.sendToOopif(
+      iframeElement,
+      `(${get_iframe_compositor_test_data})()`
+    )
+  );
+
+  // See which test data has new hit results
+  let hitResultCount = function (testData) {
+    return Object.keys(testData.hitResults).length;
+  };
+
+  let hitIframe =
+    hitResultCount(newIframeTestData) > hitResultCount(oldIframeTestData);
+  let hitParent =
+    hitResultCount(newParentTestData) > hitResultCount(oldParentTestData);
+
+  // Extract the results from the appropriate test data
+  let lastHitResult = function (testData) {
+    let lastHit =
+      testData.hitResults[Object.keys(testData.hitResults).length - 1];
+    return {
+      hitInfo: lastHit.hitResult,
+      scrollId: lastHit.scrollId,
+      layersId: lastHit.layersId,
+    };
+  };
+  if (hitIframe && hitParent) {
+    throw new Error(
+      "Both iframe and parent got hit-results, that is unexpected!"
+    );
+  } else if (hitIframe) {
+    return lastHitResult(newIframeTestData);
+  } else if (hitParent) {
+    return lastHitResult(newParentTestData);
+  } else {
+    throw new Error(
+      "Neither iframe nor parent got the hit-result, that is unexpected!"
+    );
+  }
+}