feat: log when SHOREBIRD_TOKEN is detected and successfully parsed (#2885)

packages/shorebird_cli/lib/src/auth/auth.dart

@@ -315,6 +315,8 @@ class Auth {
   void _loadCredentials() {
     final envToken = platform.environment[shorebirdTokenEnvVar];
     if (envToken != null) {
+      logger.info('$shorebirdTokenEnvVar detected');
+
       try {
         _token = CiToken.fromBase64(envToken.trim());
       } on FormatException catch (e) {
@@ -328,6 +330,8 @@ Please regenerate using `shorebird login:ci`, update the $shorebirdTokenEnvVar e
           ..detail(e.toString());
         rethrow;
       }
+
+      logger.info('$shorebirdTokenEnvVar successfully parsed');
       return;
     }
 

packages/shorebird_cli/test/src/auth/auth_test.dart

@@ -541,6 +541,9 @@ void main() {
         test('logs and throws error when token string is not valid base64',
             () async {
           expect(buildAuth, throwsA(isFormatException));
+          verify(
+            () => logger.info('$shorebirdTokenEnvVar detected'),
+          ).called(1);
           verify(
             () => logger.err(
               '''
@@ -549,6 +552,9 @@ Failed to parse CI token from environment. This likely means that your CI token
 Please regenerate using `shorebird login:ci`, update the $shorebirdTokenEnvVar environment variable, and try again.''',
             ),
           ).called(1);
+          verifyNever(
+            () => logger.info('$shorebirdTokenEnvVar successfully parsed'),
+          );
         });
       });
 
@@ -588,6 +594,10 @@ Please regenerate using `shorebird login:ci`, update the $shorebirdTokenEnvVar e
         final client = auth.client;
         expect(client, isA<http.Client>());
         expect(client, isA<AuthenticatedClient>());
+        verify(() => logger.info('$shorebirdTokenEnvVar detected')).called(1);
+        verify(
+          () => logger.info('$shorebirdTokenEnvVar successfully parsed'),
+        ).called(1);
       });
 
       test('returns a plain http client when credentials are not present.',