Convenience extensions and reorganization

Apollo.xcodeproj/project.pbxproj

@@ -21,6 +21,9 @@
 		9BDE43D122C6655300FD7C7F /* Cancellable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BDE43D022C6655200FD7C7F /* Cancellable.swift */; };
 		9BDE43DD22C6705300FD7C7F /* GraphQLHTTPResponseError.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BDE43DC22C6705300FD7C7F /* GraphQLHTTPResponseError.swift */; };
 		9BDE43DF22C6708600FD7C7F /* GraphQLHTTPRequestError.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BDE43DE22C6708600FD7C7F /* GraphQLHTTPRequestError.swift */; };
+		9BE071AD2368D08700FA5952 /* Collection+Helpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BE071AC2368D08700FA5952 /* Collection+Helpers.swift */; };
+		9BE071AF2368D34D00FA5952 /* Matchable.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BE071AE2368D34D00FA5952 /* Matchable.swift */; };
+		9BE071B12368D3F500FA5952 /* Dictionary+Helpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BE071B02368D3F500FA5952 /* Dictionary+Helpers.swift */; };
 		9BEDC79E22E5D2CF00549BF6 /* RequestCreator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BEDC79D22E5D2CF00549BF6 /* RequestCreator.swift */; };
 		9BF1A94F22CA5784005292C2 /* HTTPTransportTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BF1A94C22CA54F9005292C2 /* HTTPTransportTests.swift */; };
 		9BF1A95122CA6E71005292C2 /* GraphQLGETTransformer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9BF1A95022CA6E71005292C2 /* GraphQLGETTransformer.swift */; };
@@ -36,7 +39,7 @@
 		9F438D081E6C30B1007BDC1A /* StarWarsAPI.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 9FCE2CFA1E6C213D00E34457 /* StarWarsAPI.framework */; };
 		9F533AB31E6C4A4200CBE097 /* BatchedLoadTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9F438D0B1E6C494C007BDC1A /* BatchedLoadTests.swift */; };
 		9F55347B1DE1DB2100E54264 /* ApolloStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9F55347A1DE1DB2100E54264 /* ApolloStore.swift */; };
-		9F578D901D8D2CB300C0EA36 /* Utilities.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9F578D8F1D8D2CB300C0EA36 /* Utilities.swift */; };
+		9F578D901D8D2CB300C0EA36 /* HTTPURLResponse+Helpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9F578D8F1D8D2CB300C0EA36 /* HTTPURLResponse+Helpers.swift */; };
 		9F65B1211EC106F30090B25F /* Apollo.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 9FC750441D2A532C00458D91 /* Apollo.framework */; };
 		9F69FFA91D42855900E000B1 /* NetworkTransport.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9F69FFA81D42855900E000B1 /* NetworkTransport.swift */; };
 		9F7BA89922927A3700999B3B /* ResponsePath.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9F7BA89822927A3700999B3B /* ResponsePath.swift */; };
@@ -101,7 +104,7 @@
 		9FE1C6E71E634C8D00C02284 /* PromiseTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9FE1C6E61E634C8D00C02284 /* PromiseTests.swift */; };
 		9FE941D01E62C771007CDD89 /* Promise.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9FE941CF1E62C771007CDD89 /* Promise.swift */; };
 		9FEB050D1DB5732300DA3B44 /* JSONSerializationFormat.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9FEB050C1DB5732300DA3B44 /* JSONSerializationFormat.swift */; };
-		9FEC15B41E681DAD00D461B4 /* Collections.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9FEC15B31E681DAD00D461B4 /* Collections.swift */; };
+		9FEC15B41E681DAD00D461B4 /* GroupedSequence.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9FEC15B31E681DAD00D461B4 /* GroupedSequence.swift */; };
 		9FF33D811E48B98200F608A4 /* HTTPNetworkTransport.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9F4DAF2D1E48B84B00EBFF0B /* HTTPNetworkTransport.swift */; };
 		9FF90A611DDDEB100034C3B6 /* GraphQLResponse.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9FF90A5B1DDDEB100034C3B6 /* GraphQLResponse.swift */; };
 		9FF90A651DDDEB100034C3B6 /* GraphQLExecutor.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9FF90A5C1DDDEB100034C3B6 /* GraphQLExecutor.swift */; };
@@ -283,6 +286,9 @@
 		9BDE43D022C6655200FD7C7F /* Cancellable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Cancellable.swift; sourceTree = "<group>"; };
 		9BDE43DC22C6705300FD7C7F /* GraphQLHTTPResponseError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GraphQLHTTPResponseError.swift; sourceTree = "<group>"; };
 		9BDE43DE22C6708600FD7C7F /* GraphQLHTTPRequestError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GraphQLHTTPRequestError.swift; sourceTree = "<group>"; };
+		9BE071AC2368D08700FA5952 /* Collection+Helpers.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Collection+Helpers.swift"; sourceTree = "<group>"; };
+		9BE071AE2368D34D00FA5952 /* Matchable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Matchable.swift; sourceTree = "<group>"; };
+		9BE071B02368D3F500FA5952 /* Dictionary+Helpers.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Dictionary+Helpers.swift"; sourceTree = "<group>"; };
 		9BEDC79D22E5D2CF00549BF6 /* RequestCreator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RequestCreator.swift; sourceTree = "<group>"; };
 		9BF1A94C22CA54F9005292C2 /* HTTPTransportTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HTTPTransportTests.swift; sourceTree = "<group>"; };
 		9BF1A95022CA6E71005292C2 /* GraphQLGETTransformer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GraphQLGETTransformer.swift; sourceTree = "<group>"; };
@@ -296,7 +302,7 @@
 		9F438D0B1E6C494C007BDC1A /* BatchedLoadTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BatchedLoadTests.swift; sourceTree = "<group>"; };
 		9F4DAF2D1E48B84B00EBFF0B /* HTTPNetworkTransport.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HTTPNetworkTransport.swift; sourceTree = "<group>"; };
 		9F55347A1DE1DB2100E54264 /* ApolloStore.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ApolloStore.swift; sourceTree = "<group>"; };
-		9F578D8F1D8D2CB300C0EA36 /* Utilities.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Utilities.swift; sourceTree = "<group>"; };
+		9F578D8F1D8D2CB300C0EA36 /* HTTPURLResponse+Helpers.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "HTTPURLResponse+Helpers.swift"; sourceTree = "<group>"; };
 		9F69FFA81D42855900E000B1 /* NetworkTransport.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NetworkTransport.swift; sourceTree = "<group>"; };
 		9F7BA89822927A3700999B3B /* ResponsePath.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ResponsePath.swift; sourceTree = "<group>"; };
 		9F8622F71EC2004200C38162 /* ReadWriteFromStoreTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ReadWriteFromStoreTests.swift; sourceTree = "<group>"; };
@@ -379,7 +385,7 @@
 		9FE1C6E61E634C8D00C02284 /* PromiseTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PromiseTests.swift; sourceTree = "<group>"; };
 		9FE941CF1E62C771007CDD89 /* Promise.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Promise.swift; sourceTree = "<group>"; };
 		9FEB050C1DB5732300DA3B44 /* JSONSerializationFormat.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = JSONSerializationFormat.swift; sourceTree = "<group>"; };
-		9FEC15B31E681DAD00D461B4 /* Collections.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Collections.swift; sourceTree = "<group>"; };
+		9FEC15B31E681DAD00D461B4 /* GroupedSequence.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GroupedSequence.swift; sourceTree = "<group>"; };
 		9FF90A5B1DDDEB100034C3B6 /* GraphQLResponse.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GraphQLResponse.swift; sourceTree = "<group>"; };
 		9FF90A5C1DDDEB100034C3B6 /* GraphQLExecutor.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GraphQLExecutor.swift; sourceTree = "<group>"; };
 		9FF90A6A1DDDEB420034C3B6 /* InputValueEncodingTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = InputValueEncodingTests.swift; sourceTree = "<group>"; };
@@ -530,6 +536,7 @@
 			isa = PBXGroup;
 			children = (
 				9BDE43D022C6655200FD7C7F /* Cancellable.swift */,
+				9BE071AE2368D34D00FA5952 /* Matchable.swift */,
 			);
 			name = Protocols;
 			sourceTree = "<group>";
@@ -727,14 +734,16 @@
 			children = (
 				9FCDFD221E33A0D8007519DC /* AsynchronousOperation.swift */,
 				9B1CCDD82360F02C007C9032 /* Bundle+Helpers.swift */,
+				9BE071AC2368D08700FA5952 /* Collection+Helpers.swift */,
+				9BE071B02368D3F500FA5952 /* Dictionary+Helpers.swift */,
 				9BA3130D2302BEA5007B7FC5 /* DispatchQueue+Optional.swift */,
+				9FEC15B31E681DAD00D461B4 /* GroupedSequence.swift */,
+				9F578D8F1D8D2CB300C0EA36 /* HTTPURLResponse+Helpers.swift */,
+				9FADC8491E6B0B2300C677E6 /* Locking.swift */,
 				9FE941CF1E62C771007CDD89 /* Promise.swift */,
 				9BA1245D22DE116B00BF1D24 /* Result+Helpers.swift */,
 				9F19D8431EED568200C57247 /* ResultOrPromise.swift */,
-				9FEC15B31E681DAD00D461B4 /* Collections.swift */,
-				9FADC8491E6B0B2300C677E6 /* Locking.swift */,
 				9B1A38522332AF6F00325FB4 /* String+SHA.swift */,
-				9F578D8F1D8D2CB300C0EA36 /* Utilities.swift */,
 			);
 			name = Utilities;
 			sourceTree = "<group>";
@@ -1216,7 +1225,9 @@
 				9F86B68B1E6438D700B885FF /* GraphQLSelectionSetMapper.swift in Sources */,
 				9F55347B1DE1DB2100E54264 /* ApolloStore.swift in Sources */,
 				9BDE43D122C6655300FD7C7F /* Cancellable.swift in Sources */,
+				9BE071B12368D3F500FA5952 /* Dictionary+Helpers.swift in Sources */,
 				9F69FFA91D42855900E000B1 /* NetworkTransport.swift in Sources */,
+				9BE071AF2368D34D00FA5952 /* Matchable.swift in Sources */,
 				9FCDFD291E33D0CE007519DC /* GraphQLQueryWatcher.swift in Sources */,
 				9FC2333D1E66BBF7001E4541 /* GraphQLDependencyTracker.swift in Sources */,
 				9F19D8441EED568200C57247 /* ResultOrPromise.swift in Sources */,
@@ -1232,8 +1243,8 @@
 				C377CCA922D798BD00572E03 /* GraphQLFile.swift in Sources */,
 				9FC9A9CC1E2FD0760023C4D5 /* Record.swift in Sources */,
 				9FC4B9201D2A6F8D0046A641 /* JSON.swift in Sources */,
-				9FEC15B41E681DAD00D461B4 /* Collections.swift in Sources */,
-				9F578D901D8D2CB300C0EA36 /* Utilities.swift in Sources */,
+				9FEC15B41E681DAD00D461B4 /* GroupedSequence.swift in Sources */,
+				9F578D901D8D2CB300C0EA36 /* HTTPURLResponse+Helpers.swift in Sources */,
 				9F7BA89922927A3700999B3B /* ResponsePath.swift in Sources */,
 				9FC9A9BD1E2C271C0023C4D5 /* RecordSet.swift in Sources */,
 				9BF1A95122CA6E71005292C2 /* GraphQLGETTransformer.swift in Sources */,
@@ -1242,6 +1253,7 @@
 				9F27D4641D40379500715680 /* JSONStandardTypeConversions.swift in Sources */,
 				9B1A38532332AF6F00325FB4 /* String+SHA.swift in Sources */,
 				9BEDC79E22E5D2CF00549BF6 /* RequestCreator.swift in Sources */,
+				9BE071AD2368D08700FA5952 /* Collection+Helpers.swift in Sources */,
 				9FA6F3681E65DF4700BF8D73 /* GraphQLResultAccumulator.swift in Sources */,
 				9FF90A651DDDEB100034C3B6 /* GraphQLExecutor.swift in Sources */,
 				9FC750611D2A59C300458D91 /* GraphQLOperation.swift in Sources */,

Sources/Apollo/Bundle+Helpers.swift

@@ -1,11 +1,3 @@
-//
-//  Bundle+Helpers.swift
-//  Apollo
-//
-//  Created by Ellen Shapiro on 10/23/19.
-//  Copyright © 2019 Apollo GraphQL. All rights reserved.
-//
-
 import Foundation
 
 extension Bundle {

Sources/Apollo/Collection+Helpers.swift

@@ -0,0 +1,65 @@
+import Foundation
+
+// MARK: - Emptiness + Optionality
+
+extension Collection {
+
+  /// Convenience helper to make `guard` statements more readable
+  ///
+  /// - returns: `true` if the collection has contents.
+  var isNotEmpty: Bool {
+    return !self.isEmpty
+  }
+}
+
+extension Optional where Wrapped: Collection {
+
+  /// - returns: `true` if the collection is empty or nil
+  var isEmptyOrNil: Bool {
+    switch self {
+    case .none:
+      return true
+    case .some(let collection):
+      return collection.isEmpty
+    }
+  }
+
+  /// - returns: `true` if the collection is non-nil AND has contents.
+  var isNotEmpty: Bool {
+    switch self {
+    case .none:
+      return false
+    case .some(let collection):
+      return collection.isNotEmpty
+    }
+  }
+}
+
+// MARK: - Unzipping
+// MARK: Arrays of tuples to tuples of arrays
+
+public func unzip<Element1, Element2>(_ array: [(Element1, Element2)]) -> ([Element1], [Element2]) {
+  var array1: [Element1] = []
+  var array2: [Element2] = []
+
+  for element in array {
+    array1.append(element.0)
+    array2.append(element.1)
+  }
+
+  return (array1, array2)
+}
+
+public func unzip<Element1, Element2, Element3>(_ array: [(Element1, Element2, Element3)]) -> ([Element1], [Element2], [Element3]) {
+  var array1: [Element1] = []
+  var array2: [Element2] = []
+  var array3: [Element3] = []
+
+  for element in array {
+    array1.append(element.0)
+    array2.append(element.1)
+    array3.append(element.2)
+  }
+
+  return (array1, array2, array3)
+}

Sources/Apollo/Dictionary+Helpers.swift

@@ -0,0 +1,14 @@
+public extension Dictionary {
+  static func += (lhs: inout Dictionary, rhs: Dictionary) {
+    lhs.merge(rhs) { (_, new) in new }
+  }
+}
+
+extension Dictionary {
+  init<S: Sequence>(_ entries: S) where S.Iterator.Element == Element {
+    self = Dictionary(minimumCapacity: entries.underestimatedCount)
+    for (key, value) in entries {
+      self[key] = value
+    }
+  }
+}

Sources/Apollo/DispatchQueue+Optional.swift

@@ -1,11 +1,3 @@
-//
-//  DispatchQueue+Optional.swift
-//  Apollo
-//
-//  Created by Ellen Shapiro on 8/13/19.
-//  Copyright © 2019 Apollo GraphQL. All rights reserved.
-//
-
 import Foundation
 
 public extension DispatchQueue {

Sources/Apollo/GraphQLSelectionSet.swift

@@ -51,9 +51,11 @@ public struct GraphQLField: GraphQLSelection {
   }
 
   func cacheKey(with variables: [String: JSONEncodable]?) throws -> String {
-    if let argumentValues = try arguments?.evaluate(with: variables), !argumentValues.isEmpty {
-      let argumentsKey = orderIndependentKey(for: argumentValues)
-      return "\(name)(\(argumentsKey))"
+    if
+      let argumentValues = try arguments?.evaluate(with: variables),
+      argumentValues.isNotEmpty {
+        let argumentsKey = orderIndependentKey(for: argumentValues)
+        return "\(name)(\(argumentsKey))"
     } else {
       return name
     }

Sources/Apollo/GroupedSequence.swift

@@ -0,0 +1,41 @@
+struct GroupedSequence<Key: Equatable, Value> {
+  private(set) var keys: [Key] = []
+  fileprivate var groupsForKeys: [[Value]] = []
+
+  mutating func append(value: Value, forKey key: Key) -> (Int, Int) {
+    if let index = keys.firstIndex(where: { $0 == key }) {
+      groupsForKeys[index].append(value)
+      return (index, groupsForKeys[index].endIndex - 1)
+    } else {
+      keys.append(key)
+      groupsForKeys.append([value])
+      return (keys.endIndex - 1, 0)
+    }
+  }
+}
+
+extension GroupedSequence: Sequence {
+  func makeIterator() -> GroupedSequenceIterator<Key, Value> {
+    return GroupedSequenceIterator(base: self)
+  }
+}
+
+struct GroupedSequenceIterator<Key: Equatable, Value>: IteratorProtocol {
+  private var base: GroupedSequence<Key, Value>
+
+  private var keyIterator: EnumeratedSequence<Array<Key>>.Iterator
+
+  init(base: GroupedSequence<Key, Value>) {
+    self.base = base
+    keyIterator = base.keys.enumerated().makeIterator()
+  }
+
+  mutating func next() -> (Key, [Value])? {
+    if let (index, key) = keyIterator.next() {
+      let values = base.groupsForKeys[index]
+      return (key, values)
+    } else {
+      return nil
+    }
+  }
+}