Initial rough out of a Tabs widget.

Issue #258.

␄

lib/widget.js

@@ -1951,6 +1951,58 @@ window.NexusHoratio.widget = (function widget() {
 
   NH.xunit.testing.testCases.push(GridTestCase);
 
+  /** Tab for the {@link Tabs} widget. */
+  class TabEntry {
+  }
+
+  /* eslint-disable no-new */
+  /* eslint-disable no-unused-vars */
+  /* eslint-disable require-jsdoc */
+  class TabEntryTestCase extends NH.xunit.TestCase {
+
+    testBasic() {
+      this.assertNoRaises(
+        () => {
+          new TabEntry();
+        }
+      );
+    }
+
+  }
+  /* eslint-enable */
+
+  NH.xunit.testing.testCases.push(TabEntryTestCase);
+
+  /**
+   * Implements the Tabs pattern.
+   *
+   * Tabs widgets will need `aria-*` attributes, TBD.
+   */
+  class Tabs extends Widget {
+
+    /** @param {string} name - Name for this instance. */
+    constructor(name) {
+      super(name, 'tabs');
+    }
+
+  }
+
+  /* eslint-disable require-jsdoc */
+  class TabsTestCase extends NH.xunit.TestCase {
+
+    testDefaults() {
+      // Assemble
+      const w = new Tabs(this.id);
+
+      // Assert
+      this.assertEqual(w.container.tagName, 'TABS', 'correct element');
+    }
+
+  }
+  /* eslint-enable */
+
+  NH.xunit.testing.testCases.push(TabsTestCase);
+
   /**
    * Implements the Modal pattern.
    *