fix(numericMenu): take array into account for empty state (#4084)

This PR fixes a regression we introduced with the new behaviour of the Helper. We now preserve the empty state to avoid the parent to override the refinement when the widget is mounted. The `numericMenu` was relying on the previous behaviour to pick the "no value" element. We now check that every operator is empty.

**Before**

![before](https://user-images.githubusercontent.com/6513513/64005002-c0235600-cb0f-11e9-80a1-74382cb47ebc.gif)

**After**

![after](https://user-images.githubusercontent.com/6513513/64005037-cca7ae80-cb0f-11e9-888d-527676bff6b2.gif)

You check the behaviour on the Storybook with [the `currentRefinement` stories](https://deploy-preview-4084--instantsearchjs.netlify.com/stories/?path=/story/currentrefinements--with-numericmenu).

src/connectors/numeric-menu/__tests__/connectNumericMenu-test.js

@@ -397,7 +397,70 @@ See documentation: https://www.algolia.com/doc/api-reference/widgets/numeric-men
     });
   });
 
-  it('when the state is cleared, the "no value" value should be refined', () => {
+  it('when only the refinement is cleared, the "no value" value should be refined', () => {
+    const rendering = jest.fn();
+    const makeWidget = connectNumericMenu(rendering);
+    const listOptions = [
+      { label: 'below 10', end: 10 },
+      { label: '10 - 20', start: 10, end: 20 },
+      { label: 'more than 20', start: 20 },
+      { label: '42', start: 42, end: 42 },
+      { label: 'void' },
+    ];
+    const widget = makeWidget({
+      attribute: 'numerics',
+      items: listOptions,
+    });
+
+    const helper = jsHelper({});
+    helper.search = jest.fn();
+
+    widget.init({
+      helper,
+      state: helper.state,
+      createURL: () => '#',
+    });
+
+    const refine =
+      rendering.mock.calls[rendering.mock.calls.length - 1][0].refine;
+    // a user selects a value in the refinement list
+    refine(encodeValue(listOptions[0].start, listOptions[0].end));
+
+    widget.render({
+      results: new SearchResults(helper.state, [{}]),
+      state: helper.state,
+      helper,
+      createURL: () => '#',
+    });
+
+    // No option should be selected
+    const expectedResults0 = [...listOptions].map(mapOptionsToItems);
+    expectedResults0[0].isRefined = true;
+
+    const renderingParameters0 =
+      rendering.mock.calls[rendering.mock.calls.length - 1][0];
+    expect(renderingParameters0.items).toEqual(expectedResults0);
+
+    // Only the current refinement is cleared by a third party
+    helper.removeNumericRefinement('numerics', '<=', 10);
+
+    widget.render({
+      results: new SearchResults(helper.state, [{}]),
+      state: helper.state,
+      helper,
+      createURL: () => '#',
+    });
+
+    // No option should be selected
+    const expectedResults1 = [...listOptions].map(mapOptionsToItems);
+    expectedResults1[4].isRefined = true;
+
+    const renderingParameters1 =
+      rendering.mock.calls[rendering.mock.calls.length - 1][0];
+    expect(renderingParameters1.items).toEqual(expectedResults1);
+  });
+
+  it('when all the refinements are cleared, the "no value" value should be refined', () => {
     const rendering = jest.fn();
     const makeWidget = connectNumericMenu(rendering);
     const listOptions = [
@@ -442,11 +505,7 @@ See documentation: https://www.algolia.com/doc/api-reference/widgets/numeric-men
     expect(renderingParameters0.items).toEqual(expectedResults0);
 
     // All the refinements are cleared by a third party
-    helper.setState(
-      helper.state.setQueryParameter('numericRefinements', {
-        numerics: {},
-      })
-    );
+    helper.clearRefinements('numerics');
 
     widget.render({
       results: new SearchResults(helper.state, [{}]),

src/connectors/numeric-menu/connectNumericMenu.js

@@ -130,6 +130,7 @@ export default function connectNumericMenu(renderFn, unmountFn = noop) {
 
         this._createURL = state => facetValue =>
           createURL(refine(state, attribute, items, facetValue));
+
         this._prepareItems = state =>
           items.map(({ start, end, label }) => ({
             label,
@@ -254,7 +255,9 @@ function isRefined(state, attribute, option) {
   }
 
   if (option.start === undefined && option.end === undefined) {
-    return Object.keys(currentRefinements).length === 0;
+    return Object.keys(currentRefinements).every(
+      operator => (currentRefinements[operator] || []).length === 0
+    );
   }
 
   return undefined;