feat(shorebird_cli): show Assets.car diff if change is detected in iOS patch (#3451)

packages/shorebird_cli/bin/shorebird.dart

@@ -63,6 +63,7 @@ Command: shorebird ${args.join(' ')}
           codePushClientWrapperRef,
           codeSignerRef,
           devicectlRef,
+          diffRef,
           dittoRef,
           doctorRef,
           engineConfigRef,

packages/shorebird_cli/lib/src/archive_analysis/apple_archive_differ.dart

@@ -9,6 +9,7 @@ import 'package:crypto/crypto.dart';
 import 'package:path/path.dart' as p;
 import 'package:shorebird_cli/src/archive_analysis/archive_differ.dart';
 import 'package:shorebird_cli/src/archive_analysis/file_set_diff.dart';
+import 'package:shorebird_cli/src/executables/executables.dart';
 import 'package:shorebird_cli/src/platform/apple/macho.dart';
 
 /// {@template apple_archive_differ}
@@ -85,7 +86,7 @@ class AppleArchiveDiffer extends ArchiveDiffer {
       }
 
       for (final file in _carFiles(archivePath)) {
-        pathHashes[file.name] = await _carFileHash(file);
+        pathHashes[file.name] = await _sanitizedCarFileHash(file);
       }
 
       return pathHashes;
@@ -139,10 +140,11 @@ class AppleArchiveDiffer extends ArchiveDiffer {
     return _hash(bytes);
   }
 
-  /// Uses assetutil to write a json description of a .car file to disk and
-  /// diffs the contents of that file, less a timestamp line that changes based
-  /// on when the .car file was created.
-  Future<String> _carFileHash(ArchiveFile file) async {
+  /// Writes a json description of a .car file to a temporary location and
+  /// returns the [File].
+  ///
+  /// Equivalent of running `xcrun assetutil --info /path/to/Assets.car > outfile.json`.
+  Future<File> _carJsonFile(ArchiveFile file) async {
     final tempDir = Directory.systemTemp.createTempSync();
     final outPath = p.join(tempDir.path, file.name);
     final outputStream = OutputFileStream(outPath);
@@ -155,14 +157,51 @@ class AppleArchiveDiffer extends ArchiveDiffer {
       Process.runSync('assetutil', ['--info', outPath, '-o', assetInfoPath]);
     }
 
-    // Remove the timestamp line from the json file
-    final jsonFile = File(assetInfoPath);
+    return File(assetInfoPath);
+  }
+
+  /// Uses assetutil to write a json description of a .car file to disk and
+  /// diffs the contents of that file, less a timestamp line that changes based
+  /// on when the .car file was created.
+  Future<String> _sanitizedCarFileHash(ArchiveFile file) async {
+    final jsonFile = await _carJsonFile(file);
     final lines = jsonFile.readAsLinesSync();
     final timestampRegex = RegExp(r'^\W+"Timestamp" : \d+$');
     final linesToKeep = lines.whereNot(timestampRegex.hasMatch);
     return _hash(linesToKeep.join('\n').codeUnits);
   }
 
+  @override
+  Future<String> availableAssetDiffs({
+    required FileSetDiff fileSetDiff,
+    required String oldArchivePath,
+    required String newArchivePath,
+  }) async {
+    final diffs = <String>[];
+    for (final changedPath in fileSetDiff.changedPaths) {
+      if (changedPath.endsWith('.car')) {
+        final oldCarFile = ZipDecoder()
+            .decodeStream(InputFileStream(oldArchivePath))
+            .files
+            .firstWhere((file) => file.name == changedPath);
+        final newCarFile = ZipDecoder()
+            .decodeStream(InputFileStream(newArchivePath))
+            .files
+            .firstWhere((file) => file.name == changedPath);
+        final oldCarJsonFile = await _carJsonFile(oldCarFile);
+        final newCarJsonFile = await _carJsonFile(newCarFile);
+        final diffResult = await diff.run(
+          oldCarJsonFile.path,
+          newCarJsonFile.path,
+          colorMode: DiffColorMode.always,
+          unified: true,
+        );
+        diffs.add(diffResult.stdout as String);
+      }
+    }
+    return diffs.join('\n');
+  }
+
   @override
   bool isAssetFilePath(String filePath) {
     /// The flutter_assets directory contains the assets listed in the assets

packages/shorebird_cli/lib/src/archive_analysis/archive_differ.dart

@@ -107,4 +107,13 @@ abstract class ArchiveDiffer {
       };
     });
   }
+
+  /// Prints the diffs of the changed files to the console.
+  Future<String> availableAssetDiffs({
+    required FileSetDiff fileSetDiff,
+    required String oldArchivePath,
+    required String newArchivePath,
+  }) async {
+    return '';
+  }
 }

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

@@ -0,0 +1,41 @@
+import 'package:scoped_deps/scoped_deps.dart';
+import 'package:shorebird_cli/src/shorebird_process.dart';
+
+/// The color mode for the `diff` command.
+enum DiffColorMode {
+  /// Never color the diff.
+  never,
+
+  /// Always color the diff.
+  always,
+
+  /// Color the diff automatically based on the output device.
+  auto,
+}
+
+/// A reference to a [Diff] instance.
+final diffRef = create(Diff.new);
+
+/// The [Diff] instance available in the current zone.
+Diff get diff => read(diffRef);
+
+/// A wrapper around the `diff` command.
+class Diff {
+  /// The name of the `diff` executable.
+  static const executable = 'diff';
+
+  /// Runs the `diff` command and returns the result.
+  Future<ShorebirdProcessResult> run(
+    String fileAPath,
+    String fileBPath, {
+    required bool unified,
+    required DiffColorMode colorMode,
+  }) async {
+    return process.run(executable, [
+      if (unified) '--unified',
+      '--color=${colorMode.name}',
+      fileAPath,
+      fileBPath,
+    ]);
+  }
+}

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

@@ -4,6 +4,7 @@ export 'adb.dart';
 export 'aot_tools.dart';
 export 'bundletool.dart';
 export 'devicectl/devicectl.dart';
+export 'diff.dart';
 export 'ditto.dart';
 export 'git.dart';
 export 'gradlew.dart';

packages/shorebird_cli/lib/src/patch_diff_checker.dart

@@ -109,14 +109,24 @@ If you don't know why you're seeing this error, visit our troubleshooting page a
           yellow.wrap(
             archiveDiffer.assetsFileSetDiff(contentDiffs).prettyString,
           ),
-        )
-        ..info(
-          yellow.wrap(
-            '''
+        );
+
+      final diffs = await archiveDiffer.availableAssetDiffs(
+        fileSetDiff: contentDiffs,
+        oldArchivePath: releaseArchive.path,
+        newArchivePath: localArchive.path,
+      );
+      if (diffs.isNotEmpty) {
+        logger.info(diffs);
+      }
+
+      logger.info(
+        yellow.wrap(
+          '''
 
 If you don't know why you're seeing this error, visit our troubleshooting page at ${assetChangesTroubleshootingUrl.toLink()}''',
-          ),
-        );
+        ),
+      );
 
       if (!allowAssetChanges) {
         if (!shorebirdEnv.canAcceptUserInput) {

packages/shorebird_cli/test/src/archive_analysis/apple_archive_differ_test.dart

@@ -1,9 +1,15 @@
 // cspell:words xcarchive xcarchives xcframeworks xcframework
+import 'package:mocktail/mocktail.dart';
 import 'package:path/path.dart' as p;
+import 'package:scoped_deps/scoped_deps.dart';
 import 'package:shorebird_cli/src/archive_analysis/archive_analysis.dart';
+import 'package:shorebird_cli/src/executables/executables.dart';
 import 'package:shorebird_cli/src/platform.dart';
+import 'package:shorebird_cli/src/shorebird_process.dart';
 import 'package:test/test.dart';
 
+import '../mocks.dart';
+
 void main() {
   final xcarchiveFixturesBasePath = p.join('test', 'fixtures', 'xcarchives');
   final baseIpaPath = p.join(xcarchiveFixturesBasePath, 'base.xcarchive.zip');
@@ -15,6 +21,10 @@ void main() {
     xcarchiveFixturesBasePath,
     'changed_asset.xcarchive.zip',
   );
+  final changedCarXcarchivePath = p.join(
+    xcarchiveFixturesBasePath,
+    'changed_assets_car.xcarchive.zip',
+  );
   final changedDartXcarchivePath = p.join(
     xcarchiveFixturesBasePath,
     'changed_dart.xcarchive.zip',
@@ -43,9 +53,22 @@ void main() {
   );
 
   group(AppleArchiveDiffer, () {
+    late Diff diff;
     late AppleArchiveDiffer differ;
 
+    R runWithOverrides<R>(R Function() body) {
+      return runScoped(
+        body,
+        values: {diffRef.overrideWith(() => diff)},
+      );
+    }
+
+    setUpAll(() {
+      registerFallbackValue(DiffColorMode.always);
+    });
+
     setUp(() {
+      diff = MockDiff();
       differ = const AppleArchiveDiffer();
     });
 
@@ -191,6 +214,65 @@ void main() {
           );
         });
       });
+
+      group('availableAssetDiffs', () {
+        group('when a car file has changed', () {
+          const diffOutput = 'diff output';
+
+          setUp(() {
+            when(
+              () => diff.run(
+                any(),
+                any(),
+                colorMode: any(named: 'colorMode'),
+                unified: any(named: 'unified'),
+              ),
+            ).thenAnswer(
+              (_) async => const ShorebirdProcessResult(
+                exitCode: 1,
+                stdout: diffOutput,
+                stderr: '',
+              ),
+            );
+          });
+
+          test('shows asset diffs', () async {
+            final fileSetDiff = await differ.changedFiles(
+              baseIpaPath,
+              changedCarXcarchivePath,
+            );
+            await runWithOverrides(() async {
+              expect(
+                await differ.availableAssetDiffs(
+                  fileSetDiff: fileSetDiff,
+                  oldArchivePath: baseIpaPath,
+                  newArchivePath: changedCarXcarchivePath,
+                ),
+                equals(diffOutput),
+              );
+            });
+          });
+        });
+
+        group('when no car files have changed', () {
+          test('shows no asset diffs', () async {
+            final fileSetDiff = await differ.changedFiles(
+              baseIpaPath,
+              changedDartXcarchivePath,
+            );
+            await runWithOverrides(() async {
+              expect(
+                await differ.availableAssetDiffs(
+                  fileSetDiff: fileSetDiff,
+                  oldArchivePath: baseIpaPath,
+                  newArchivePath: changedDartXcarchivePath,
+                ),
+                isEmpty,
+              );
+            });
+          });
+        });
+      });
     });
 
     group('xcframework', () {

packages/shorebird_cli/test/src/archive_analysis/archive_differ_test.dart

@@ -78,4 +78,11 @@ class TestArchiveDiffer extends ArchiveDiffer {
 
   @override
   bool isNativeFilePath(String filePath) => true;
+
+  @override
+  Future<String> availableAssetDiffs({
+    required FileSetDiff fileSetDiff,
+    required String oldArchivePath,
+    required String newArchivePath,
+  }) async => '';
 }

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

@@ -0,0 +1,54 @@
+import 'package:mocktail/mocktail.dart';
+import 'package:scoped_deps/scoped_deps.dart';
+import 'package:shorebird_cli/src/executables/diff.dart';
+import 'package:shorebird_cli/src/shorebird_process.dart';
+import 'package:test/test.dart';
+
+import '../mocks.dart';
+
+void main() {
+  group(Diff, () {
+    late ShorebirdProcess process;
+    late Diff diff;
+
+    R runWithOverrides<R>(R Function() body) {
+      return runScoped(body, values: {processRef.overrideWith(() => process)});
+    }
+
+    setUp(() {
+      process = MockShorebirdProcess();
+      diff = Diff();
+    });
+
+    group('run', () {
+      setUp(() {
+        when(() => process.run(any(), any())).thenAnswer(
+          (_) async => const ShorebirdProcessResult(
+            exitCode: 0,
+            stdout: 'stdout',
+            stderr: 'stderr',
+          ),
+        );
+      });
+
+      test('returns the result of the `diff` command', () async {
+        await runWithOverrides(
+          () => diff.run(
+            'fileA',
+            'fileB',
+            unified: true,
+            colorMode: DiffColorMode.always,
+          ),
+        );
+        verify(
+          () => process.run(Diff.executable, [
+            '--unified',
+            '--color=always',
+            'fileA',
+            'fileB',
+          ]),
+        ).called(1);
+      });
+    });
+  });
+}

packages/shorebird_cli/test/src/mocks.dart

@@ -91,6 +91,8 @@ class MockCodeSigner extends Mock implements CodeSigner {}
 
 class MockDevicectl extends Mock implements Devicectl {}
 
+class MockDiff extends Mock implements Diff {}
+
 class MockDitto extends Mock implements Ditto {}
 
 class MockDirectory extends Mock implements Directory {}

packages/shorebird_cli/test/src/patch_diff_checker_test.dart

@@ -72,6 +72,13 @@ void main() {
       when(
         () => archiveDiffer.containsPotentiallyBreakingNativeDiffs(any()),
       ).thenReturn(false);
+      when(
+        () => archiveDiffer.availableAssetDiffs(
+          fileSetDiff: any(named: 'fileSetDiff'),
+          oldArchivePath: any(named: 'oldArchivePath'),
+          newArchivePath: any(named: 'newArchivePath'),
+        ),
+      ).thenAnswer((_) async => '');
 
       when(() => httpClient.send(any())).thenAnswer(
         (_) async => http.StreamedResponse(const Stream.empty(), HttpStatus.ok),
@@ -221,6 +228,13 @@ void main() {
               '''Your app contains asset changes, which will not be included in the patch.''',
             ),
           ).called(1);
+          verify(
+            () => archiveDiffer.availableAssetDiffs(
+              fileSetDiff: any(named: 'fileSetDiff'),
+              oldArchivePath: any(named: 'oldArchivePath'),
+              newArchivePath: any(named: 'newArchivePath'),
+            ),
+          ).called(1);
           verify(
             () => logger.info(yellow.wrap(assetsDiffPrettyString)),
           ).called(1);