Add build tests to CI (firebase#4)

Author: paulb777

Diff for: .github/workflows/spm.yml

@@ -0,0 +1,23 @@
+name: spm
+
+on:
+  pull_request:
+  schedule:
+    # Run every day at 11pm (PST) - cron uses UTC times
+    - cron:  '0 7 * * *'
+
+jobs:
+  swiftpm-build-tests:
+    runs-on: macOS-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Initialize xcodebuild
+      run: xcodebuild -list
+    - name: iOS Simulator Build Tests
+      run: xcodebuild -scheme abseil build -sdk 'iphonesimulator' -destination 'platform=iOS Simulator,name=iPhone 11'
+    - name: macos Build Tests
+      run: xcodebuild -scheme abseil build -sdk 'macosx' -destination 'platform=OS X,arch=x86_64',
+    - name: tvOS Build Tests
+      run: xcodebuild -scheme abseil build -sdk "appletvsimulator" -destination 'platform=tvOS Simulator,name=Apple TV'
+    - name: iOS Device Build Tests
+      run: xcodebuild -scheme abseil build -sdk 'iphoneos'      

Diff for: .gitignore

@@ -13,3 +13,5 @@ CMakeLists.txt.user
 # Ignore generated python artifacts
 *.pyc
 copts/__pycache__/
+# SwiftPM build directory
+.swiftpm/

Diff for: Package.swift

@@ -261,8 +261,18 @@ let package = Package(
       publicHeadersPath: ".",
       cSettings: [
         .headerSearchPath("./"),
+      ],
+      linkerSettings: [
+        .linkedFramework("CoreFoundation"),
       ]
     ),
+    .testTarget(
+      name: "build-test",
+      dependencies: [
+        "abseil",
+      ],
+      path: "SwiftPMTests/build-test"
+    ),
   ],
 
   cxxLanguageStandard: CXXLanguageStandard.gnucxx14

Diff for: SwiftPMTests/build-test/test.cc

@@ -0,0 +1,48 @@
+// 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.
+
+// absl imports from Firestore and gRPC
+  
+#include "absl/algorithm/container.h"
+#include "absl/base/attributes.h"
+#include "absl/base/call_once.h"
+#include "absl/base/casts.h"
+#include "absl/base/config.h"
+#include "absl/base/internal/endian.h"
+#include "absl/base/internal/unaligned_access.h"
+#include "absl/base/macros.h"
+#include "absl/base/optimization.h"
+#include "absl/base/port.h"
+#include "absl/container/flat_hash_map.h"
+#include "absl/container/inlined_vector.h"
+#include "absl/memory/memory.h"
+#include "absl/meta/type_traits.h"
+#include "absl/strings/ascii.h"
+#include "absl/strings/escaping.h"
+#include "absl/strings/match.h"
+#include "absl/strings/numbers.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/str_format.h"
+#include "absl/strings/str_join.h"
+#include "absl/strings/str_replace.h"
+#include "absl/strings/str_split.h"
+#include "absl/strings/string_view.h"
+#include "absl/strings/strip.h"
+#include "absl/strings/substitute.h"
+#include "absl/synchronization/mutex.h"
+#include "absl/time/clock.h"
+#include "absl/time/time.h"
+#include "absl/types/any.h"
+#include "absl/types/optional.h"
+#include "absl/types/variant.h"