Add property wrapper for Firestore (#8614)

* Add FIRRequest
* Make FIRPredicate public
* Make init public
* Bugfixes
* Add debug print
* Move to main thread
* Undo "Move to main thread"
* Add FirebaseStore
* Add placeholder value
* Treat CollectionReference as Query
* Change let to var
* Replace getDocuments with addSnapshotListener
* Feedback from review
* Add sample project
* Rename folder, Rename FirebaseStore to QueryStore, Rename FIRRequest to FirestoreQuery, Rename several functions, attributes and parameter labels, Extend error handling
* Update some access specifiers, Add factory methods
* Add orderBy and limitTo
* Update Copyright, Rename FIRPredicate to QueryPredicate, Rename QueryStore to FirestoreQueryObservable, Rename some parameters, Remove setter for wrappedValue
* Rename store to firestoreQueryObservable
* Add limitToLast
* Move different types to different files
* Add FirestoreQueryConfiguration and projectedValue to dynamically change predicates & collectionPath
* Add Documentation
* Update documentation
* Add example app
* Address feedback from review
* Fix whitespace
* Address feedback from review
* Update data
* Add error handling (Manually cherry pick from Morten's PR: https://github.com/chFlorian/firebase-ios-sdk/pull/2)
* Update sample app to demonstrate error handling
* Cleanup
* Fix warning regarding unwrapping
* Fix tvOS availability
* Fix typos
* Experimental: use @FirestoreQuery inside a view model (Hint: this doesn't work)
* Fix platform availabilities
* Update data
* Improve error handling
* Cleanup
* Address feedback from review
* Update data
* Cleanup
* Alternate signature for predicates
* Address feedback from review
* Remove trailing backtick

Co-authored-by: Florian Schweizer <post.an.flo@gmail.com>
Co-authored-by: Morten Bek Ditlevsen <bek@termestrup.dk>

Author: 3 people

.gitignore

@@ -151,3 +151,8 @@ FirebaseInAppMessaging/Tests/Integration/FunctionalTestApp/App/InAppMessaging-Ex
 # FIRAppCheckTestApp
 FirebaseAppCheck/Apps/FIRAppCheckTestApp/FIRAppCheckTestApp/GoogleService-Info.plist
 FirebaseAppCheck/Apps/AppCheckCustomProvideApp/AppCheckCustomProvideApp/GoogleService-Info.plist
+
+# FirestoreSample
+/Example/FirestoreSample/FirestoreSample/GoogleService-Info.plist
+/Example/FirestoreSample/ui-debug.log
+/Example/FirestoreSample/firestore-debug.log

Example/FirestoreSample/.firebaserc

@@ -0,0 +1 @@
+{}

Example/FirestoreSample/FirestoreSample.xcodeproj/project.pbxproj

@@ -0,0 +1,39 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import SwiftUI
+import Firebase
+
+@main
+struct FirestoreSampleApp: App {
+  init() {
+    FirebaseApp.configure()
+
+    let settings = Firestore.firestore().settings
+    settings.host = "localhost:8080"
+    settings.isPersistenceEnabled = false
+    settings.isSSLEnabled = false
+    Firestore.firestore().settings = settings
+  }
+
+  var body: some Scene {
+    WindowGroup {
+      NavigationView {
+        MenuView()
+      }
+      // see https://stackoverflow.com/q/63740788/
+      .navigationViewStyle(StackNavigationViewStyle())
+    }
+  }
+}

Example/FirestoreSample/FirestoreSample/App/FirestoreSampleApp.swift

@@ -0,0 +1,20 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.157",
+          "green" : "0.792",
+          "red" : "1.000"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}