fix: FilterStorage URL encoding (#698)

* Add quotation for filter value in url encoded string
* Add convenient string wrapping functions for URL encoding to improve readability

Author: VladislavFitz

Sources/AlgoliaSearchClient/Helpers/String/String+Wrapping.swift

@@ -0,0 +1,15 @@
+//
+//  String+Wrapping.swift
+//  
+//
+//  Created by Vladislav Fitc on 23/11/2020.
+//
+
+import Foundation
+
+extension String {
+  
+  func wrappedInQuotes() -> String { "\"\(self)\"" }
+  func wrappedInBrackets() -> String { "[\(self)]" }
+  
+}

Sources/AlgoliaSearchClient/Models/Search/Query/Query+URLEncodable.swift

@@ -12,7 +12,7 @@ extension Query {
   struct URLEncoder<Key: RawRepresentable> where Key.RawValue == String {
 
     var queryItems: [URLQueryItem] = []
-
+        
     mutating func set<T: URLEncodable>(_ value: T?, for key: Key) {
       guard let value = value else { return }
       queryItems.append(.init(name: key.rawValue, value: value.urlEncodedString))
@@ -30,39 +30,39 @@ extension Query {
 
     mutating func set<S: Sequence>(_ value: S?, for key: Key) where S.Element == [String] {
       guard let value = value else { return }
-      let valueToSet = "[\(value.map { "[\($0.map(\.urlEncodedString).sorted().joined(separator: ","))]" }.joined(separator: ","))]"
+      let valueToSet = value.map { $0.map(\.urlEncodedString).sorted().joined(separator: ",").wrappedInBrackets() }.joined(separator: ",").wrappedInBrackets()
       queryItems.append(.init(name: key.rawValue, value: valueToSet))
     }
 
     mutating func set(_ value: FiltersStorage?, for key: Key) {
-      guard let value = value else { return }
+      guard let value = value?.rawValue else { return }
       func toString(_ singleOrList: SingleOrList<String>) -> String {
         switch singleOrList {
         case .single(let value):
-          return value
+          return value.wrappedInQuotes()
         case .list(let list):
-          return "[\(list.joined(separator: ","))]"
+          return list.map { $0.wrappedInQuotes() }.joined(separator: ",").wrappedInBrackets()
         }
       }
-      let valueToSet = "[\(value.rawValue.map(toString).joined(separator: ","))]"
+      let valueToSet = value.map(toString).joined(separator: ",").wrappedInBrackets()
       queryItems.append(.init(name: key.rawValue, value: valueToSet))
     }
 
     mutating func set<S: Sequence>(_ value: S?, for key: Key) where S.Element == BoundingBox {
       guard let value = value else { return }
-      let valueToSet = "[\(value.map(\.urlEncodedString).joined(separator: ","))]"
+      let valueToSet = value.map(\.urlEncodedString).joined(separator: ",").wrappedInBrackets()
       queryItems.append(.init(name: key.rawValue, value: valueToSet))
     }
 
     mutating func set<S: Sequence>(_ value: S?, for key: Key) where S.Element == AroundPrecision {
       guard let value = value else { return }
-      let valueToSet = "[\(value.map(\.urlEncodedString).joined(separator: ","))]"
+      let valueToSet = value.map(\.urlEncodedString).joined(separator: ",").wrappedInBrackets()
       queryItems.append(.init(name: key.rawValue, value: valueToSet))
     }
 
     mutating func set<S: Sequence>(_ value: S?, for key: Key) where S.Element == Polygon {
       guard let value = value else { return }
-      let valueToSet = "[\(value.map(\.urlEncodedString).joined(separator: ","))]"
+      let valueToSet = value.map(\.urlEncodedString).joined(separator: ",").wrappedInBrackets()
       queryItems.append(.init(name: key.rawValue, value: valueToSet))
     }
 

Tests/AlgoliaSearchClientTests/Unit/QueryTests.swift

@@ -94,10 +94,10 @@ class QueryTests: XCTestCase {
       "attributesToRetrieve=attr1,attr2,attr3",
       "restrictSearchableAttributes=rattr1,rattr2",
       "filters=(color:red%20OR%20color:yellow)%20AND%20on-sale",
-      "facetFilters=%5B%5Bcolor:red,color:blue%5D,size:M%5D",
-      "optionalFilters=%5B%5Bcolor:red,color:yellow%5D,on-sale%5D",
-      "numericFilters=%5B%5Bprice%3E100,length%3C1000%5D,metrics%3E5%5D",
-      "tagFilters=%5B%5Btag1,tag2%5D,tag3%5D",
+      "facetFilters=%5B%5B%22color:red%22,%22color:blue%22%5D,%22size:M%22%5D",
+      "optionalFilters=%5B%5B%22color:red%22,%22color:yellow%22%5D,%22on-sale%22%5D",
+      "numericFilters=%5B%5B%22price%3E100%22,%22length%3C1000%22%5D,%22metrics%3E5%22%5D",
+      "tagFilters=%5B%5B%22tag1%22,%22tag2%22%5D,%22tag3%22%5D",
       "sumOrFiltersScores=false",
       "facets=facet1,facet2,facet3",
       "maxValuesPerFacet=10",