Refactor resources for SPM and CocoaPods.

GoogleSignIn.podspec

@@ -32,7 +32,9 @@ The Google Sign-In SDK allows users to sign in with their Google account from th
   s.dependency 'AppAuth', '~> 1.4'
   s.dependency 'GTMAppAuth', '~> 1.0'
   s.dependency 'GTMSessionFetcher/Core', '~> 1.1'
-  s.resources = 'GoogleSignIn/Resources/GoogleSignIn.bundle'
+  s.resource_bundle = {
+    'GoogleSignIn' => ['GoogleSignIn/Sources/{Resources,Strings}/*']
+  }
   s.pod_target_xcconfig = {
     'GCC_PREPROCESSOR_DEFINITIONS' => 'GID_SDK_VERSION=' + s.version.to_s,
     'HEADER_SEARCH_PATHS' => '"${PODS_TARGET_SRCROOT}"'

GoogleSignIn/Sources/NSBundle+GID3PAdditions.m

@@ -19,13 +19,24 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+#if SWIFT_PACKAGE
+NSString *const GoogleSignInBundleName = @"GoogleSignIn_GoogleSignIn";
+#else
+NSString *const GoogleSignInBundleName = @"GoogleSignIn";
+#endif
+
 @implementation NSBundle (GID3PAdditions)
 
 + (nullable NSBundle *)gid_frameworkBundle {
-  NSString* mainBundlePath = [[NSBundle mainBundle] resourcePath];
-  NSString* frameworkBundlePath = [mainBundlePath
-      stringByAppendingPathComponent:@"GoogleSignIn.bundle"];
-  return [NSBundle bundleWithPath:frameworkBundlePath];
+  // Look for the resource bundle in the main bundle.
+  NSString *path = [[NSBundle mainBundle] pathForResource:GoogleSignInBundleName
+                                                   ofType:@"bundle"];
+  if (!path) {
+    // If we can't find the resource bundle in the main bundle, use the framework bundle instead.
+    NSString *path = [[NSBundle mainBundle] pathForResource:GoogleSignInBundleName
+                                                     ofType:@"framework"];
+  }
+  return [NSBundle bundleWithPath:path];
 }
 
 + (void)gid_registerFonts {

Package.swift

@@ -21,6 +21,7 @@ let googleSignInVersion = "6.0.0"
 
 let package = Package(
   name: "GoogleSignIn",
+  defaultLocalization: "en",
   platforms: [.iOS(.v9)],
   products: [
     .library(
@@ -59,6 +60,10 @@ let package = Package(
         .product(name: "GTMSessionFetcherCore", package: "GTMSessionFetcher"),
       ],
       path: "GoogleSignIn/Sources",
+      resources: [
+        .process("Resources"),
+        .process("Strings"),
+      ],
       publicHeadersPath: "Public",
       cSettings: [
         .headerSearchPath("../../"),