Adapter.clip spec

Author: dhilt

src/component/workflow.ts

@@ -190,6 +190,7 @@ export class Workflow {
               break;
             case Process.userClip:
               run(PreFetch)(payload);
+              break;
             default:
               run(PreFetch)();
           }

tests/_index.js

@@ -26,8 +26,8 @@ getTestBed().initTestEnvironment(
 const testContext = require.context(
   './',
   false,
-  /(common|datasource\-get|initial\-load|scroll\-basic|min\-max\-indexes|eof|dynamic\-size|adapter\.reload|adapter\.prepend|dynamic\-height\-reload|dynamic\-height\-scroll|adapter\.append\-prepend|adapter\.check|adapter\.remove)\.spec\.ts/
-  //(adapter\.remove)\.spec\.ts/
+  /(common|datasource\-get|initial\-load|scroll\-basic|min\-max\-indexes|eof|dynamic\-size|adapter\.reload|adapter\.prepend|dynamic\-height\-reload|dynamic\-height\-scroll|adapter\.append\-prepend|adapter\.check|adapter\.remove|adapter\.clip)\.spec\.ts/
+  //(adapter\.clip)\.spec\.ts/
 );
 
 function requireAll(requireContext) {

tests/adapter.clip.spec.ts

@@ -0,0 +1,90 @@
+import { makeTest, TestBedConfig } from './scaffolding/runner';
+import { Misc } from './miscellaneous/misc';
+import { testItemsCounter, ItemsCounter } from './miscellaneous/itemsCounter';
+
+const configList: TestBedConfig[] = [{
+  datasourceSettings: { startIndex: 100, bufferSize: 4, padding: 0.22, itemSize: 20 },
+  templateSettings: { viewportHeight: 71, itemHeight: 20 }
+}, {
+  datasourceSettings: { startIndex: 1, bufferSize: 5, padding: 0.2, itemSize: 20 },
+  templateSettings: { viewportHeight: 100 }
+}, {
+  datasourceSettings: { startIndex: -15, bufferSize: 12, padding: 0.98, itemSize: 20 },
+  templateSettings: { viewportHeight: 66, itemHeight: 20 }
+}, {
+  datasourceSettings: { startIndex: 1, bufferSize: 5, padding: 1, horizontal: true, itemSize: 90 },
+  templateSettings: { viewportWidth: 450, itemWidth: 90, horizontal: true }
+}, {
+  datasourceSettings: { startIndex: -74, bufferSize: 4, padding: 0.72, horizontal: true, itemSize: 75 },
+  templateSettings: { viewportWidth: 300, itemWidth: 75, horizontal: true }
+}];
+
+configList.forEach(config => config.datasourceSettings.adapter = true);
+
+export const getItemsCounter = (
+  settings: TestBedConfig, misc: Misc, itemSize: number, firstIndex: number, lastIndex: number
+): ItemsCounter => {
+  const { startIndex, padding } = misc.scroller.settings;
+  const viewportSize = misc.getViewportSize(settings);
+
+  const backwardLimit = viewportSize * padding;
+  const forwardLimit = viewportSize + backwardLimit;
+  const itemsCounter = new ItemsCounter();
+  const { backward, forward } = itemsCounter;
+
+  backward.count = Math.ceil(backwardLimit / itemSize);
+  forward.count = Math.ceil(forwardLimit / itemSize);
+
+  backward.index = startIndex - backward.count;
+  forward.index = startIndex + forward.count - 1;
+
+  itemsCounter.backward.padding = (backward.index - firstIndex) * itemSize;
+  itemsCounter.forward.padding = (lastIndex - forward.index) * itemSize;
+
+  return itemsCounter;
+};
+
+const shouldClipAfterAppend = (config: TestBedConfig) => (misc: Misc) => (done: Function) => {
+  let indexToAppend = -Infinity;
+  const NEW_ITEMS_COUNT = 50;
+  const { itemSize } = config.datasourceSettings;
+  let firstIndex: number, lastIndex: number;
+
+  spyOn(misc.workflow, 'finalize').and.callFake(() => {
+    const cycles = misc.workflow.cyclesDone;
+    if (cycles === 1) {
+      indexToAppend = misc.scroller.buffer.getIndexToAppend();
+      const itemsToAppend = Array.from(Array(NEW_ITEMS_COUNT), (_, x) => ({
+        id: indexToAppend - x,
+        text: `!item #${indexToAppend - x}`
+      }));
+      misc.datasource.adapter.append(itemsToAppend);
+    } else if (cycles === 2) {
+      firstIndex = <number>misc.scroller.buffer.firstIndex;
+      lastIndex = <number>misc.scroller.buffer.lastIndex;
+      expect(lastIndex).toEqual(indexToAppend + NEW_ITEMS_COUNT - 1);
+      expect(misc.padding.backward.getSize()).toEqual(0);
+      misc.datasource.adapter.clip();
+    } else {
+      // user clip requires additional reflow to remove DOM elements
+      setTimeout(() => {
+        const itemsCounter = getItemsCounter(config, misc, itemSize, firstIndex, lastIndex);
+        testItemsCounter(config, misc, itemsCounter);
+        done();
+      });
+    }
+  });
+};
+
+describe('Adapter Clip Spec', () => {
+
+  configList.forEach(config =>
+    makeTest({
+      config,
+      title: 'should clip after append many',
+      it: shouldClipAfterAppend(config)
+    })
+  );
+
+});
+