feat(searchFunction): make search function provide a better API

* feat(searchFunction): Offer full helper support in search function

This implementation offers:
 - a full helper to modify the parameters before sending the request
 - all the other search function (searchOnce, searchForFacetValues)
 - compatibility with async code (no oops effect)

* fix(slider): Make sure the slider doesn't update the state twice

This commit adds constraints to make sure that a refine call doesn't
trigger a new state update and search. It also adds undefined as a
value that can be passed as "no boundary selected" for min and max
in the refine function (slider connector).

* fix(searchFunction): rm unnecessary state update in internals

* chore(naming): change name of search helper function

* chore(test): test searchFunction in a less altered env

The previous setup was not compatible with the kind of manipulation done
for implementing the `searchFunction`.

src/components/Slider/Slider.js

@@ -35,14 +35,17 @@ class Slider extends Component {
     return this.props.min === this.props.max;
   }
 
-  handleChange = ({values}) => {
+  handleChange = ({min, max, values}) => {
     // when Slider is disabled, we alter `min, max` values
     // in order to render a "disabled state" Slider. Since we alter
     // theses values, Rheostat trigger a "change" event which trigger a new
     // search to Algolia with wrong values.
     if (!this.isDisabled) {
       const {refine} = this.props;
-      refine(values);
+      refine([
+        min === values[0] ? undefined : values[0],
+        max === values[1] ? undefined : values[1],
+      ]);
     }
   }
 

src/connectors/range-slider/connectRangeSlider.js

@@ -119,14 +119,21 @@ export default function connectRangeSlider(renderFn) {
 
       init({helper, instantSearchInstance}) {
         this._refine = bounds => newValues => {
-          helper.clearRefinements(attributeName);
-          if (!bounds.min || newValues[0] > bounds.min) {
-            helper.addNumericRefinement(attributeName, '>=', formatToNumber(newValues[0]));
+          const currentValues = [
+            helper.getNumericRefinement(attributeName, '>='),
+            helper.getNumericRefinement(attributeName, '<='),
+          ];
+
+          if (currentValues[0] !== newValues[0] || currentValues[1] !== newValues[1]) {
+            helper.clearRefinements(attributeName);
+            if (!bounds.min || newValues[0] > bounds.min) {
+              helper.addNumericRefinement(attributeName, '>=', formatToNumber(newValues[0]));
+            }
+            if (!bounds.max || newValues[1] < bounds.max) {
+              helper.addNumericRefinement(attributeName, '<=', formatToNumber(newValues[1]));
+            }
+            helper.search();
           }
-          if (!bounds.max || newValues[1] < bounds.max) {
-            helper.addNumericRefinement(attributeName, '<=', formatToNumber(newValues[1]));
-          }
-          helper.search();
         };
 
         const stats = {

src/lib/InstantSearch.js

@@ -121,19 +121,27 @@ Usage: instantsearch({
     );
 
     if (this._searchFunction) {
-      this.helper = Object.create(helper);
-      this.helper.search = () => {
-        helper.setState(this.helper.state);
-        this._searchFunction(helper);
+      this._mainHelperSearch = helper.search.bind(helper);
+      helper.search = () => {
+        const helperSearchFunction = algoliasearchHelper(
+          {
+            addAlgoliaAgent: () => {},
+            search: () => {},
+          },
+          helper.state.index,
+          helper.state
+        );
+        helperSearchFunction.once('search', state => {
+          helper.overrideStateWithoutTriggeringChangeEvent(state);
+          this._mainHelperSearch();
+        });
+        this._searchFunction(helperSearchFunction);
       };
-      this._init(helper.state, this.helper);
-      helper.on('result', this._render.bind(this, this.helper));
-    } else {
-      this.helper = helper;
-      this._init(helper.state, this.helper);
-      this.helper.on('result', this._render.bind(this, this.helper));
     }
 
+    this.helper = helper;
+    this._init(helper.state, this.helper);
+    this.helper.on('result', this._render.bind(this, this.helper));
     this.helper.search();
   }
 

src/lib/__tests__/InstantSearch-test-2.js

@@ -0,0 +1,38 @@
+import sinon from 'sinon';
+
+// import algoliaSearchHelper from 'algoliasearch-helper';
+import InstantSearch from '../InstantSearch';
+
+const appId = 'appId';
+const apiKey = 'apiKey';
+const indexName = 'lifecycle';
+
+describe.only('InstantSearch lifecycle', () => {
+  it('calls the provided searchFunction when used', () => {
+    const searchFunctionSpy = sinon.spy(h => {
+      h.setQuery('test').search();
+    });
+
+    const fakeClient = {
+      search: sinon.spy(),
+      addAlgoliaAgent: () => {},
+    };
+
+    const search = new InstantSearch({
+      appId,
+      apiKey,
+      indexName,
+      searchFunction: searchFunctionSpy,
+      createAlgoliaClient: () => fakeClient,
+    });
+
+    expect(searchFunctionSpy.callCount).toBe(0);
+    expect(fakeClient.search.callCount).toBe(0);
+
+    search.start();
+
+    expect(searchFunctionSpy.callCount).toBe(1);
+    expect(search.helper.state.query).toBe('test');
+    expect(fakeClient.search.callCount).toBe(1);
+  });
+});

src/lib/__tests__/InstantSearch-test.js

@@ -125,22 +125,6 @@ describe('InstantSearch lifecycle', () => {
     });
   });
 
-  it('calls the provided searchFunction when used', () => {
-    const searchSpy = sinon.spy(h => {
-      h.setQuery('test').search();
-    });
-    search = new InstantSearch({
-      appId,
-      apiKey,
-      indexName,
-      searchFunction: searchSpy,
-    });
-    search.start();
-    expect(searchSpy.calledOnce).toBe(true);
-    expect(helper.state.query).toBe('test');
-    expect(helperSearchSpy.calledOnce).toBe(true);
-  });
-
   it('does not fail when passing same references inside multiple searchParameters props', () => {
     const disjunctiveFacetsRefinements = {fruits: ['apple']};
     const facetsRefinements = disjunctiveFacetsRefinements;