feat(shorebird_cli): add xcodeVersion method to xcodebuild wrapper (#1360)

packages/shorebird_cli/lib/src/executables/xcodebuild.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 
 import 'package:mason_logger/mason_logger.dart';
 import 'package:path/path.dart' as p;
+import 'package:pub_semver/pub_semver.dart';
 import 'package:scoped/scoped.dart';
 import 'package:shorebird_cli/src/process.dart';
 
@@ -106,4 +107,41 @@ class XcodeBuild {
       schemes: schemes,
     );
   }
+
+  /// Gets the currently installed version of Xcode.
+  ///
+  /// Invokes `xcodebuild -version` and parses the output.
+  /// Output is expected to be of the form:
+  ///
+  ///   $ /usr/bin/xcodebuild -version
+  ///   Xcode 15.0
+  ///   Build version 15A240d
+  Future<Version> xcodeVersion() async {
+    const arguments = ['-version'];
+    final result = await process.run(
+      executable,
+      arguments,
+    );
+
+    if (result.exitCode != ExitCode.success.code) {
+      throw ProcessException(executable, arguments, '${result.stderr}');
+    }
+
+    final lines = LineSplitter.split('${result.stdout}').map((e) => e.trim());
+    var versionString = lines.firstOrNull?.split(' ').lastOrNull;
+    if (versionString == null) {
+      throw FormatException(
+        'Could not parse Xcode version from output: "${result.stdout}".',
+      );
+    }
+
+    // [Version.parse] requires a patch number. If Xcode does not report a patch
+    // number (e.g. "12.0"), add a patch number of 0 (e.g. "12.0.0")
+    final noPachNumberRegex = RegExp(r'^\d+\.\d+$');
+    if (noPachNumberRegex.hasMatch(versionString)) {
+      versionString += '.0';
+    }
+
+    return Version.parse(versionString);
+  }
 }

packages/shorebird_cli/test/src/executables/xcodebuild_test.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import 'package:mason_logger/mason_logger.dart';
 import 'package:mocktail/mocktail.dart';
 import 'package:path/path.dart' as p;
+import 'package:pub_semver/pub_semver.dart';
 import 'package:scoped/scoped.dart';
 import 'package:shorebird_cli/src/executables/executables.dart';
 import 'package:shorebird_cli/src/process.dart';
@@ -13,6 +14,7 @@ import '../mocks.dart';
 void main() {
   group(XcodeBuild, () {
     late ShorebirdProcess process;
+    late ShorebirdProcessResult processResult;
     late XcodeBuild xcodeBuild;
 
     R runWithOverrides<R>(R Function() body) {
@@ -32,6 +34,7 @@ void main() {
 
     setUp(() {
       process = MockShorebirdProcess();
+      processResult = MockShorebirdProcessResult();
       xcodeBuild = runWithOverrides(XcodeBuild.new);
     });
 
@@ -132,5 +135,97 @@ To add iOS, run "flutter create . --platforms ios"''',
         ).called(1);
       });
     });
+
+    group('xcodeVersion', () {
+      late ExitCode exitCode;
+      late String stdout;
+
+      setUp(() {
+        when(() => process.run(XcodeBuild.executable, ['-version']))
+            .thenAnswer((_) async => processResult);
+        when(() => processResult.exitCode).thenAnswer((_) => exitCode.code);
+        when(() => processResult.stdout).thenAnswer((_) => stdout);
+      });
+
+      group('when a non-zero exit code is returned', () {
+        const errorMessage = 'An unexpected error occurred.';
+        setUp(() {
+          stdout = '';
+          exitCode = ExitCode.cantCreate;
+          when(() => processResult.stderr).thenReturn(errorMessage);
+        });
+
+        test('throws a ProcessException', () async {
+          expect(
+            () => runWithOverrides(xcodeBuild.xcodeVersion),
+            throwsA(
+              isA<ProcessException>()
+                  .having((e) => e.message, 'message', errorMessage),
+            ),
+          );
+        });
+      });
+
+      group('when stdout contains unexpected output', () {
+        setUp(() {
+          exitCode = ExitCode.success;
+        });
+
+        test('throws FormatException if output is empty', () async {
+          stdout = '';
+          expect(
+            () => runWithOverrides(xcodeBuild.xcodeVersion),
+            throwsA(
+              isA<FormatException>().having(
+                (e) => e.message,
+                'message',
+                'Could not parse Xcode version from output: "".',
+              ),
+            ),
+          );
+        });
+
+        test('throws FormatException if output does not contain version',
+            () async {
+          stdout = 'unexpected output';
+          expect(
+            () => runWithOverrides(xcodeBuild.xcodeVersion),
+            throwsA(
+              isA<FormatException>().having(
+                (e) => e.message,
+                'message',
+                'Could not parse "output".',
+              ),
+            ),
+          );
+        });
+      });
+
+      group('when stdout contains valid output', () {
+        setUp(() {
+          exitCode = ExitCode.success;
+        });
+
+        test('returns correct version with major, minor, and build numbers',
+            () async {
+          stdout = '''
+Xcode 14.3.1
+Build version 14E300c
+''';
+          final version = await runWithOverrides(xcodeBuild.xcodeVersion);
+          expect(version, Version(14, 3, 1));
+        });
+
+        test('returns correct version with only major and minor numbers',
+            () async {
+          stdout = '''
+Xcode 15.0
+Build version 15A240d
+''';
+          final version = await runWithOverrides(xcodeBuild.xcodeVersion);
+          expect(version, Version(15, 0, 0));
+        });
+      });
+    });
   });
 }