refactor: consistent error handling (#792)

* Replace custom PrefixedString error with DecodingError

* Replace InsightsEvent.Resources.Error with DecodingFailure error

* Make ObjectIDChecker and ObjectIDChecker.Error public

* Make SwitchHostError and BodyAPIKeyError public

Author: VladislavFitz

Sources/AlgoliaSearchClient/Client/AccountClient.swift

@@ -89,9 +89,9 @@ public struct AccountClient {
 
 }
 
-extension AccountClient {
+public extension AccountClient {
 
-  public enum Error: Swift.Error {
+  enum Error: Swift.Error {
     case sourceNotFound
     case existingDestination
     case sameApplicationID

Sources/AlgoliaSearchClient/Command/Command+Custom.swift

@@ -36,22 +36,18 @@ extension Command {
          urlRequest: URLRequest,
          requestOptions: RequestOptions?) throws {
       self.callType = callType
-      guard let method = urlRequest.httpMethod.flatMap(HTTPMethod.init(rawValue:)) else {
-        throw AlgoliaCommandError.invalidHTTPMethod
+      self.method = urlRequest.httpMethod.flatMap(HTTPMethod.init(rawValue:)) ?? .get
+      guard let url = urlRequest.url else {
+        throw URLRequest.FormatError.missingURL
       }
-      self.method = method
-      guard let path = urlRequest.url?.path, let pathURL = URL(string: path) else {
-        throw AlgoliaCommandError.invalidPath
+      guard let pathURL = URL(string: url.path) else {
+        throw URLRequest.FormatError.invalidPath(url.path)
       }
       self.path = pathURL
       self.body = urlRequest.httpBody
       self.requestOptions = requestOptions
     }
 
-    enum AlgoliaCommandError: Error {
-      case invalidHTTPMethod
-      case invalidPath
-    }
   }
 
 }

Sources/AlgoliaSearchClient/Helpers/ObjectIDChecker.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct ObjectIDChecker {
+public struct ObjectIDChecker {
 
   static func checkObjectID<T: Encodable>(_ object: T) throws {
     let data = try JSONEncoder().encode(object)
@@ -26,7 +26,7 @@ struct ObjectIDChecker {
     }
   }
 
-  enum Error: Swift.Error {
+  public enum Error: Swift.Error {
     case missingObjectIDProperty
 
     var localizedDescription: String {

Sources/AlgoliaSearchClient/Index/Index+Index.swift

@@ -67,10 +67,13 @@ public extension Index {
     switch result {
     case .success:
       return true
-    case .failure(let error) where (error as? HTTPError)?.statusCode == .notFound:
-      return false
     case .failure(let error):
-      throw error
+      switch error {
+      case TransportError.httpError(let httpError) where httpError.statusCode == .notFound:
+        return false
+      default:
+        throw error
+      }
     }
   }
 

Sources/AlgoliaSearchClient/Models/Common/CompositeError.swift

@@ -0,0 +1,22 @@
+//
+//  CompositeError.swift
+//  
+//
+//  Created by Vladislav Fitc on 21/07/2022.
+//
+
+import Foundation
+
+public struct CompositeError: Error {
+
+  public let errors: [Error]
+
+  public init(errors: [Error]) {
+    self.errors = errors
+  }
+
+  public static func with(_ errors: Error...) -> Self {
+    CompositeError(errors: errors)
+  }
+
+}

Sources/AlgoliaSearchClient/Models/Data structures/PrefixedString.swift

@@ -31,7 +31,7 @@ struct PrefixedString: CustomStringConvertible, Codable {
     if let prefixedString = PrefixedString(rawValue: rawValue) {
       self = prefixedString
     } else {
-      throw Error.wrongFormat
+      throw DecodingError.dataCorrupted(.init(codingPath: decoder.codingPath, debugDescription: "\(rawValue) doesn't match the `prefix(value)` format"))
     }
   }
 
@@ -44,10 +44,6 @@ struct PrefixedString: CustomStringConvertible, Codable {
     return "\(prefix)(\(value))"
   }
 
-  enum Error: Swift.Error {
-    case wrongFormat
-  }
-
 }
 
 extension PrefixedString {

Sources/AlgoliaSearchClient/Models/Insights/EventConstructionError.swift

@@ -7,14 +7,14 @@
 
 import Foundation
 
-extension InsightsEvent {
+public extension InsightsEvent {
 
-  public enum Constraints {
+  enum Constraints {
     public static let maxObjectIDsCount = 20
     public static let maxFiltersCount = 10
   }
 
-  public enum ConstructionError: Error {
+  enum ConstructionError: Error {
 
     case emptyEventName
     case objectIDsCountOverflow

Sources/AlgoliaSearchClient/Models/Insights/InsightsEvent+Resources.swift

@@ -43,18 +43,35 @@ extension InsightsEvent.Resources: Codable {
 
     let container = try decoder.container(keyedBy: CodingKeys.self)
 
-    if let objectIDs = try? container.decode([ObjectID].self, forKey: .objectIDs) {
+    let objectIDsDecodingError: Error
+    let filtersDecodingError: Error
+
+    do {
+      let objectIDs = try container.decode([ObjectID].self, forKey: .objectIDs)
       if let positions = try? container.decode([Int].self, forKey: .positions) {
         self = .objectIDsWithPositions(zip(objectIDs, positions).map { $0 })
       } else {
         self = .objectIDs(objectIDs)
       }
-    } else if let filters = try? container.decode([String].self, forKey: .filters) {
+      return
+    } catch let error {
+      objectIDsDecodingError = error
+    }
+
+    do {
+      let filters = try container.decode([String].self, forKey: .filters)
       self = .filters(filters)
-    } else {
-      throw Error.decodingFailure
+      return
+    } catch let error {
+      filtersDecodingError = error
     }
 
+    let compositeError = CompositeError.with(objectIDsDecodingError, filtersDecodingError)
+    typealias Keys = InsightsEvent.Resources.CodingKeys
+    let context = DecodingError.Context(codingPath: decoder.codingPath,
+                                        debugDescription: "Neither \(Keys.filters.rawValue), nor \(Keys.objectIDs.rawValue) key found on decoder",
+                                        underlyingError: compositeError)
+    throw DecodingError.dataCorrupted(context)
   }
 
   public func encode(to encoder: Encoder) throws {
@@ -76,22 +93,3 @@ extension InsightsEvent.Resources: Codable {
   }
 
 }
-
-public extension InsightsEvent.Resources {
-
-  enum Error: Swift.Error {
-    case decodingFailure
-  }
-
-}
-
-extension InsightsEvent.Resources.Error: LocalizedError {
-
-  public var errorDescription: String? {
-    switch self {
-    case .decodingFailure:
-      return "Neither \(InsightsEvent.Resources.CodingKeys.filters.rawValue), nor \(InsightsEvent.Resources.CodingKeys.objectIDs.rawValue) key found on decoder"
-    }
-  }
-
-}

Sources/AlgoliaSearchClient/Models/Search/Indexing/Scope.swift

@@ -51,7 +51,7 @@ extension Scope {
 
 }
 
-public struct ScopeComponent: StringOption & ProvidingCustomOption {
+public struct ScopeComponent: StringOption, ProvidingCustomOption {
 
   public let rawValue: String
 

Sources/AlgoliaSearchClient/Models/Search/Query/Auxiliary/Point.swift

@@ -88,7 +88,9 @@ extension Point: Codable {
       self = stringForm.point
     } else {
       let encoded = (try? String(data: JSONEncoder().encode(JSON(from: decoder)), encoding: .utf8)) ?? ""
-      throw DecodingError.dataCorrupted(DecodingError.Context(codingPath: [], debugDescription: "The format \(encoded) doesn't match \"22.2268,84.8463\" string or {\"lat\": 22.2268, \"lng\": 84.8463 } dictionary"))
+      let context = DecodingError.Context(codingPath: decoder.codingPath,
+                                          debugDescription: "The format \(encoded) doesn't match \"22.2268,84.8463\" string or {\"lat\": 22.2268, \"lng\": 84.8463 } dictionary")
+      throw DecodingError.dataCorrupted(context)
     }
   }