From 6aedb1d6cf616ba4cc9d516d906232bf14fc2225 Mon Sep 17 00:00:00 2001
From: Alexandre Stanislawski <alexandre.stanislawski@algolia.com>
Date: Tue, 2 Jun 2015 14:38:37 +0200
Subject: [PATCH] Fix algolia/algoliasearch-helper-js#84 : Add a more friendly
 way to update a single parameter on SearchParameters

---
 .../src/SearchParameters/index.js             | 23 +++++++-
 .../SearchParameters.setQueryParameter.js     | 57 +++++++++++++++++++
 ...=> SearchParameters.setQueryParameters.js} |  0
 3 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParameter.js
 rename packages/algoliasearch-helper/test/spec/{SearchParameters.setQueryParams.js => SearchParameters.setQueryParameters.js} (100%)

diff --git a/packages/algoliasearch-helper/src/SearchParameters/index.js b/packages/algoliasearch-helper/src/SearchParameters/index.js
index 82c82e6007..a85026fc6b 100644
--- a/packages/algoliasearch-helper/src/SearchParameters/index.js
+++ b/packages/algoliasearch-helper/src/SearchParameters/index.js
@@ -706,13 +706,32 @@ SearchParameters.prototype = {
     return Object.freeze( newState );
   },
   /**
-   * Function that let the user set any of the parameters with a plain object.
+   * Let the user set a specific value for a given parameter. Will return the
+   * same instance if the parameter is invalid or if the value is the same as the
+   * previous one.
+   * @method
+   * @param {string} parameter the parameter name
+   * @param {any} value the value to be set, must be compliant with the definition of the attribute on the object
+   * @return {SearchParameters} the updated state
+   */
+  setQueryParameter : function setParameter( parameter, value ) {
+    var k = keys( this );
+    if( k.indexOf( parameter ) === -1 ) return this;
+    if( this[ parameter ] === value ) return this;
+
+    return this.mutateMe( function updateParameter( newState ) {
+      newState[ parameter ] = value;
+      return newState;
+    } );
+  },
+  /**
+   * Let the user set any of the parameters with a plain object.
    * It won't let the user define custom properties.
    * @method
    * @param {object} params all the keys and the values to be updated
    * @return {SearchParameters} a new updated instance
    */
-  setQueryParameters : function setQueryParams( params ) {
+  setQueryParameters : function setQueryParameters( params ) {
     return this.mutateMe( function merge( newInstance ) {
       var ks = keys( newInstance );
       forEach( ks, function( k ) {
diff --git a/packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParameter.js b/packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParameter.js
new file mode 100644
index 0000000000..3a2260e485
--- /dev/null
+++ b/packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParameter.js
@@ -0,0 +1,57 @@
+"use strict";
+var test = require( "tape" );
+//var _ = require( "lodash" );
+var SearchParameters = require( "../../src/SearchParameters" );
+
+test( "setqueryparameter should update existing parameter", function( t ) {
+  var sp = new SearchParameters( {
+    facets : ["facet"]
+  } );
+
+  var newValue = [];
+  var newsp = sp.setQueryParameter( "facets", newValue );
+
+  t.equal( newsp.facets, newValue, "update of an existing parameter" );
+
+  t.end();
+} );
+
+test( "setqueryparameter should add non-existing parameter", function( t ) {
+  var sp = new SearchParameters( {
+    facets : ["facet"]
+  } );
+
+  var newValue = [ "attributesToHighlight" ];
+  var newsp = sp.setQueryParameter( "attributesToHighlight", newValue );
+
+  t.equal( newsp.attributesToHighlight, newValue, "add new parameter" );
+
+  t.end();
+} );
+
+test( "setQueryParameter should not create a new instance if the update is non effective", function( t ) {
+  var sp = new SearchParameters( {
+    facets : ["facet"],
+    maxValuesPerFacet : 10
+  } );
+
+  var newValue = 10;
+  var newsp = sp.setQueryParameter( "maxValuesPerFacet", newValue );
+
+  t.equal( newsp, sp, "No change should result in the same instance" );
+
+  t.end();
+} );
+
+test( "setQueryParameter should not create a new instance if the parameter is unknown", function( t ) {
+  var sp = new SearchParameters( {
+    facets : ["facet"]
+  } );
+
+  var newValue = [ "attributesToHighlight" ];
+  var newsp = sp.setQueryParameter( "unknown", newValue );
+
+  t.equal( newsp, sp, "Unknown parameter should return the same instance" );
+
+  t.end();
+} );
diff --git a/packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParams.js b/packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParameters.js
similarity index 100%
rename from packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParams.js
rename to packages/algoliasearch-helper/test/spec/SearchParameters.setQueryParameters.js