scroll-into-view · stipsan · May 13, 2018 · May 12, 2018 · May 12, 2018 · May 12, 2018
diff --git a/.gitignore b/.gitignore
@@ -3,6 +3,7 @@ node_modules
 # Cypress stuff
 **/cypress/screenshots
 **/cypress/videos
+**/junit
 
 # Typescript stuff
 typings
@@ -14,4 +15,5 @@ dist
 es
 umd
 /compute.js
-/index.js
+/index.js
+/types.js
diff --git a/.prettierignore b/.prettierignore
@@ -1,2 +1,3 @@
 node_modules
+tests/web-platform/resources
 package.json
diff --git a/src/compute.ts b/src/compute.ts
@@ -214,7 +214,7 @@ export default (
   }
 
   let targetRect = target.getBoundingClientRect()
-  const viewport = document.documentElement
+  const viewport = document.scrollingElement || document.documentElement
 
   // Collect all the scrolling boxes, as defined in the spec: https://drafts.csswg.org/cssom-view/#scrolling-box
   const frames: Element[] = []

diff --git a/src/index.ts b/src/index.ts
@@ -1,9 +1,9 @@
 import compute from './compute'
 import {
-  ScrollBehavior,
-  CustomScrollBehaviorCallback,
   CustomScrollAction,
+  CustomScrollBehaviorCallback,
   Options as BaseOptions,
+  ScrollBehavior,
 } from './types'
 
 export interface StandardBehaviorOptions extends BaseOptions {
@@ -20,6 +20,7 @@ export interface Options<T = any> extends BaseOptions {
 // Wait with checking if native smooth-scrolling exists until scrolling is invoked
 // This is much more friendly to server side rendering envs, and testing envs like jest
 let supportsScrollBehavior
+let scrollingElement
 
 const isFunction = (arg: any): arg is Function => {
   return typeof arg == 'function'
@@ -32,8 +33,12 @@ const defaultBehavior = (
   actions: CustomScrollAction[],
   behavior: ScrollBehavior = 'auto'
 ) => {
+  // Because of quirksmode
+  if (!scrollingElement) {
+    scrollingElement = document.scrollingElement || document.documentElement
+  }
   if (supportsScrollBehavior === undefined) {
-    supportsScrollBehavior = 'scrollBehavior' in document.documentElement.style
+    supportsScrollBehavior = 'scrollBehavior' in scrollingElement.style
   }
 
   actions.forEach(({ el, top, left }) => {
@@ -42,7 +47,7 @@ const defaultBehavior = (
     if (el.scroll && supportsScrollBehavior) {
       el.scroll({ top, left, behavior })
     } else {
-      if (el === document.documentElement) {
+      if (el === scrollingElement) {
         window.scrollTo(left, top)
       } else {
         el.scrollTop = top

diff --git a/tests/web-platform/README.md b/tests/web-platform/README.md
@@ -0,0 +1,22 @@
+# Run tests
+
+You'll need two terminal sessions for this.
+
+1. Install deps `yarn`
+2. Start the server: `yarn start`
+3. In the other session: `yarn test`
+
+You can also open http://localhost:3000 in the browser to run the tests.
+
+# Why are tests setup like this?
+
+Two reasons.
+
+1. It helps with staying in sync with the same tests that browsers run when checking if they are implementing the spec correctly.
+2. Easier to run tests in different browsers, compared to if a more conventional cypress or jest setup were used.
+
+## How tests are kept in sync with w3c
+
+The `resources` and `css` folders are rougly equivalent with their counterparts on here: https://github.com/w3c/web-platform-tests
+
+Except that anything that isn't needed to run the tests related to `scrollIntoView` is stripped out.
diff --git a/tests/web-platform/css/cssom-view/scrollIntoView-smooth.html b/tests/web-platform/css/cssom-view/scrollIntoView-smooth.html
@@ -0,0 +1,102 @@
+<!DOCTYPE HTML>
+<script src="/node_modules/scroll-into-view-if-needed/umd/scroll-into-view-if-needed.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<title>Check End Position of smooth scrollIntoView</title>
+<div id="container" style="height: 2500px; width: 2500px;">
+  <div id="content" style="height: 500px; width: 500px;margin-left: 1000px; margin-right: 1000px; margin-top: 1000px;margin-bottom: 1000px;background-color: red">
+  </div>
+  <div id="shadow"></div>
+</div>
+<script>
+var content_height = 500;
+var content_width = 500;
+var window_height = document.scrollingElement.clientHeight;
+var window_width = document.scrollingElement.clientWidth;
+var content = document.getElementById("content");
+add_completion_callback(() => document.getElementById("container").remove());
+
+function waitForScrollEnd() {
+  var last_changed_frame = 0;
+  var last_x = window.scrollX;
+  var last_y = window.scrollY;
+  return new Promise((resolve, reject) => {
+    function tick(frames) {
+      // We requestAnimationFrame either for 500 frames or until 20 frames with
+      // no change have been observed.
+      if (frames >= 500 || frames - last_changed_frame > 20) {
+        resolve();
+      } else {
+        if (window.scrollX != last_x || window.scrollY != last_y) {
+          last_changed_frame = frames;
+          last_x = window.scrollX;
+          last_y = window.scrollY;
+        }
+        requestAnimationFrame(tick.bind(null, frames + 1));
+      }
+    }
+    tick(0);
+  });
+}
+
+// When testing manually, we need an additional frame at beginning
+// to trigger the effect.
+requestAnimationFrame(() => {
+promise_test(t => {
+  window.scrollTo(0, 0);
+  var expected_x = content.offsetLeft + content_width - window_width;
+  var expected_y = content.offsetTop + content_height - window_height;
+  assert_not_equals(window.scrollX, expected_x, "scrollX");
+  assert_not_equals(window.scrollY, expected_y, "scrollY");
+  scrollIntoView(content, {behavior: "smooth", block: "nearest", inline:
+"nearest"});
+  return waitForScrollEnd().then(() => {
+    assert_approx_equals(window.scrollX, expected_x, 1, "scrollX");
+    assert_approx_equals(window.scrollY, expected_y, 1, "scrollY");
+  });
+}, "Smooth scrollIntoView should scroll the element to the 'nearest' position");
+
+promise_test(t => {
+  window.scrollTo(0, 0);
+  var expected_x = content.offsetLeft;
+  var expected_y = content.offsetTop;
+  assert_not_equals(window.scrollX, expected_x, "scrollX");
+  assert_not_equals(window.scrollY, expected_y, "scrollY");
+  scrollIntoView(content, {behavior: "smooth", block: "start", inline:
+"start"});
+  return waitForScrollEnd().then(() => {
+    assert_approx_equals(window.scrollX, expected_x, 1, "scrollX");
+    assert_approx_equals(window.scrollY, expected_y, 1, "scrollY");
+  });
+}, "Smooth scrollIntoView should scroll the element to the 'start' position");
+
+promise_test(t => {
+  window.scrollTo(0, 0);
+  var expected_x = content.offsetLeft + (content_width - window_width) / 2;
+  var expected_y = content.offsetTop + (content_height - window_height) / 2;
+  assert_not_equals(window.scrollX, expected_x, "scrollX");
+  assert_not_equals(window.scrollY, expected_y, "scrollY");
+  scrollIntoView(content, {behavior: "smooth", block: "center", inline:
+"center"});
+  return waitForScrollEnd().then(() => {
+    assert_approx_equals(window.scrollX, expected_x, 1, "scrollX");
+    assert_approx_equals(window.scrollY, expected_y, 1, "scrollY");
+  });
+}, "Smooth scrollIntoView should scroll the element to the 'center' position");
+
+promise_test(t => {
+  window.scrollTo(0, 0);
+  var expected_x = content.offsetLeft + content_width - window_width;
+  var expected_y = content.offsetTop + content_height - window_height;
+  assert_not_equals(window.scrollX, expected_x, "scrollX");
+  assert_not_equals(window.scrollY, expected_y, "scrollY");
+  scrollIntoView(content, {behavior: "smooth", block: "end", inline:
+"end"});
+  return waitForScrollEnd().then(() => {
+    assert_approx_equals(window.scrollX, expected_x, 1, "scrollX");
+    assert_approx_equals(window.scrollY, expected_y, 1, "scrollY");
+  });
+}, "Smooth scrollIntoView should scroll the element to the 'end' position");
+
+});
+</script>
diff --git a/tests/web-platform/css/cssom-view/scrollintoview.html b/tests/web-platform/css/cssom-view/scrollintoview.html
@@ -0,0 +1,113 @@
+<!DOCTYPE html>
+<title>CSSOM View - scrollIntoView</title>
+<meta charset="utf-8">
+<link rel="author" title="Chris Wu" href="mailto:pwx.frontend@gmail.com">
+<link rel="help" href="https://drafts.csswg.org/cssom-view/#dom-element-scrollintoview">
+<link rel="help" href="https://heycam.github.io/webidl/#es-operations">
+<link rel="help" href="https://heycam.github.io/webidl/#es-overloads">
+<meta name="flags" content="dom">
+<script src="/node_modules/scroll-into-view-if-needed/umd/scroll-into-view-if-needed.js"></script>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style>
+body.running { margin: 0; padding: 4000px; overflow: hidden }
+body.running #testDiv {
+  width: 200px;
+  height: 200px;
+  background-color: lightgreen;
+}
+</style>
+<body class=running>
+<div id=testDiv></div>
+<div id="log"></div>
+<script>
+var testDiv = document.getElementById('testDiv');
+
+var expectedXLeft = 4000;
+var expectedXRight = 4000 - window.innerWidth + testDiv.clientWidth;
+var expectedXCenter = 4000 - (window.innerWidth / 2) + (testDiv.clientWidth / 2);
+
+var expectedYTop = 4000;
+var expectedYBottom = 4000 - window.innerHeight + testDiv.clientHeight;
+var expectedYCenter = 4000 - (window.innerHeight / 2) + (testDiv.clientHeight / 2);
+
+[
+  ["omitted argument", "nearest", expectedYTop],
+  [true, "nearest", expectedYTop],
+  [false, "nearest", expectedYBottom],
+  [undefined, "nearest", expectedYTop],
+  [null, "nearest", expectedYTop],
+  [{}, "nearest", expectedYTop],
+  [{block: "center", inline: "center"}, expectedXCenter, expectedYCenter],
+  [{block: "start", inline: "start"}, expectedXLeft, expectedYTop],
+  [{block: "end", inline: "end"}, expectedXRight, expectedYBottom],
+  [{block: "nearest", inline: "nearest"}, "nearest", "nearest"],
+].forEach(([input, expectedX, expectedY]) => {
+  test(() => {
+    window.scrollTo(0, 0);
+    testScrollIntoView(input);
+    var x = (expectedX === "nearest") ? expectedXRight : expectedX;
+    var y = (expectedY === "nearest") ? expectedYBottom : expectedY;
+    assert_approx_equals(window.scrollX, x, 0.5, 'scrollX');
+    assert_approx_equals(window.scrollY, y, 0.5, 'scrollY');
+  }, `scrollIntoView(${format_input(input)}) starting at left,top`);
+
+  test(() => {
+    window.scrollTo(0, 12000);
+    testScrollIntoView(input);
+    var x = (expectedX === "nearest") ? expectedXRight : expectedX;
+    var y = (expectedY === "nearest") ? expectedYTop : expectedY;
+    assert_approx_equals(window.scrollX, x, 0.5, 'scrollX');
+    assert_approx_equals(window.scrollY, y, 0.5, 'scrollY');
+  }, `scrollIntoView(${format_input(input)}) starting at left,bottom`);
+
+  test(() => {
+    window.scrollTo(12000, 0);
+    testScrollIntoView(input);
+    var x = (expectedX === "nearest") ? expectedXLeft : expectedX;
+    var y = (expectedY === "nearest") ? expectedYBottom : expectedY;
+    assert_approx_equals(window.scrollX, x, 0.5, 'scrollX');
+    assert_approx_equals(window.scrollY, y, 0.5, 'scrollY');
+  }, `scrollIntoView(${format_input(input)}) starting at right,top`);
+
+  test(() => {
+    window.scrollTo(12000, 12000);
+    testScrollIntoView(input);
+    var x = (expectedX === "nearest") ? expectedXLeft : expectedX;
+    var y = (expectedY === "nearest") ? expectedYTop : expectedY;
+    assert_approx_equals(window.scrollX, x, 0.5, 'scrollX');
+    assert_approx_equals(window.scrollY, y, 0.5, 'scrollY');
+  }, `scrollIntoView(${format_input(input)}) starting at right,bottom`);
+});
+
+function testScrollIntoView(input) {
+  if (input === "omitted argument") {
+    scrollIntoView(testDiv);
+  } else {
+    scrollIntoView(testDiv, input);
+  }
+}
+
+// This formats dict as a string suitable as test name.
+// format_value() is provided by testharness.js,
+// which also preserves sign for -0.
+function format_dict(dict) {
+  const props = [];
+  for (let prop in dict) {
+    props.push(`${prop}: ${format_value(dict[prop])}`);
+  }
+  return `{${props.join(', ')}}`;
+}
+
+function format_input(input) {
+  if (input === "omitted argument") {
+    return "";
+  } else if (input === null || typeof input !== "object") {
+    return format_value(input);
+  }
+  return format_dict(input);
+}
+
+document.body.classList.remove('running');
+window.scrollTo(0, 0);
+</script>
diff --git a/tests/web-platform/cypress/integration/index.js b/tests/web-platform/cypress/integration/index.js
@@ -1,13 +1,13 @@
-describe('web-platform-tests by w3c', function() {
-  it('css/cssom-view/scrollintoview.html', () => {
-    cy.visit('/')
+describe('css/cssom-view', () => {
+  // @TODO maybe there is a dynamic way to generate a list over tests
 
-    cy.get('#summary .pass').should('contain', '40 Pass')
-  })
-
-  it('scrollIntoView-smooth.html', () => {
-    cy.visit('/smooth')
+  const tests = ['scrollintoview.html', 'scrollIntoView-smooth.html']
+  tests.forEach(test => {
+    it(`implements ${test} correctly`, () => {
+      cy.visit(`/css/cssom-view/${test}`)
 
-    cy.get('#summary .pass').should('contain', '4 Pass')
+      cy.get('#summary .pass').should('exist')
+      cy.get('#summary .fail').should('not.exist')
+    })
   })
 })