DevTools: Convert FilteredListWidget to use an optional provider

third_party/WebKit/LayoutTests/http/tests/inspector-unit/filtered-list-widget-providers.js

Index: third_party/WebKit/LayoutTests/http/tests/inspector-unit/filtered-list-widget-providers.js
diff --git a/third_party/WebKit/LayoutTests/http/tests/inspector-unit/filtered-list-widget-providers.js b/third_party/WebKit/LayoutTests/http/tests/inspector-unit/filtered-list-widget-providers.js
new file mode 100644
index 0000000000000000000000000000000000000000..44774ddb2726dee6bd173c7884b6455f8460cee9
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/http/tests/inspector-unit/filtered-list-widget-providers.js
@@ -0,0 +1,59 @@
+TestRunner.loadLazyModules(['quick_open']).then(test);
+function test() {
+  TestRunner.addResult(
+      'Test that FilteredListWidget.setProvider changes the provider.');
+
+  var StubProvider = class extends QuickOpen.FilteredListWidget.Provider {
+    constructor(input) {
+      super();
+      this._input = input
+    }
+    itemKeyAt(itemIndex) { return this._input[itemIndex]; }
+    itemScoreAt(itemIndex) { return 0; }
+    itemCount() { return this._input.length; }
+    shouldShowMatchingItems() { return true; }
+    renderItem(item, query, titleElement, subtitleElement) {
+      titleElement.textContent = this._input[item];
+    }
+  };
+
+  var filteredListWidget = new QuickOpen.FilteredListWidget(null, []);
+  filteredListWidget.showAsDialog();
+
+  TestRunner.runTests([
+    function providerWithOneItem() {
+      return setProvider(new StubProvider(['One Item']));
+    },
+    function nullProvider() {
+      return setProvider(null);
+    },
+    function providerWithTwoItems() {
+      return setProvider(new StubProvider(['First Item', 'Second item']));
+    },
+    function providerWithNoItems() {
+      return setProvider(new StubProvider([]));
+    }
+  ]);
+
+  function setProvider(provider) {
+    var promise = TestRunner.addSniffer(filteredListWidget, "_itemsFilteredForTest").then(dump);
+    filteredListWidget.setProvider(provider);
+    return promise;
+  }
+
+  function dump() {
+    var list = filteredListWidget._list;
+    if (filteredListWidget._bottomElementsContainer.classList.contains('hidden')) {
+      TestRunner.addResult('Output: <hidden>');
+      return;
+    }
+    if (list.element.classList.contains('hidden')) {
+      TestRunner.addResult('Output: ' + filteredListWidget._notFoundElement.textContent);
+      return;
+    }
+    var output = [];
+    for (var i = 0; i < list.length(); ++i)
+      output.push(filteredListWidget._provider.itemKeyAt(list.itemAtIndex(i)));
+    TestRunner.addResult('Output:' + JSON.stringify(output));
+  }
+}