[flutter_plugin_tools] Fix build-examples for packages

script/tool/CHANGELOG.md

@@ -1,4 +1,8 @@
-## NEXT
+## 0.5.1+1
+
+- Fixed `build-examples` to work for non-plugin packages.
+
+## 0.5.1
 
 - Added Android native integration test support to `native-test`.
 - Added a new `android-lint` command to lint Android plugin native code.

script/tool/lib/src/build_examples_command.dart

@@ -99,38 +99,60 @@ class BuildExamplesCommand extends PackageLoopingCommand {
   Future<PackageResult> runForPackage(Directory package) async {
     final List<String> errors = <String>[];
 
+    final bool isPlugin = isFlutterPlugin(package);
     final Iterable<_PlatformDetails> requestedPlatforms = _platforms.entries
         .where(
             (MapEntry<String, _PlatformDetails> entry) => getBoolArg(entry.key))
         .map((MapEntry<String, _PlatformDetails> entry) => entry.value);
-    final Set<_PlatformDetails> buildPlatforms = <_PlatformDetails>{};
-    final Set<_PlatformDetails> unsupportedPlatforms = <_PlatformDetails>{};
-    for (final _PlatformDetails platform in requestedPlatforms) {
-      if (pluginSupportsPlatform(platform.pluginPlatform, package)) {
-        buildPlatforms.add(platform);
-      } else {
-        unsupportedPlatforms.add(platform);
-      }
-    }
+
+    // Platform support is checked at the package level for plugins; there is
+    // no package-level platform information for non-plugin packages.
+    final Set<_PlatformDetails> buildPlatforms = isPlugin
+        ? requestedPlatforms
+            .where((_PlatformDetails platform) =>
+                pluginSupportsPlatform(platform.pluginPlatform, package))
+            .toSet()
+        : requestedPlatforms.toSet();
     if (buildPlatforms.isEmpty) {
       final String unsupported = requestedPlatforms.length == 1
           ? '${requestedPlatforms.first.label} is not supported'
-          : 'None of [${requestedPlatforms.map((_PlatformDetails p) => p.label).join(',')}] are supported';
+          : 'None of [${requestedPlatforms.map((_PlatformDetails p) => p.label).join(', ')}] are supported';
       return PackageResult.skip('$unsupported by this plugin');
     }
     print('Building for: '
-        '${buildPlatforms.map((_PlatformDetails platform) => platform.label).join(',')}');
+        '${buildPlatforms.map((_PlatformDetails platform) => platform.label).join(', ')}');
+
+    final Set<_PlatformDetails> unsupportedPlatforms =
+        requestedPlatforms.toSet().difference(buildPlatforms);
     if (unsupportedPlatforms.isNotEmpty) {
+      final List<String> skippedPlatforms = unsupportedPlatforms
+          .map((_PlatformDetails platform) => platform.label)
+          .toList();
+      skippedPlatforms.sort();
       print('Skipping unsupported platform(s): '
-          '${unsupportedPlatforms.map((_PlatformDetails platform) => platform.label).join(',')}');
+          '${skippedPlatforms.join(', ')}');
     }
     print('');
 
-    for (final Directory example in getExamplesForPlugin(package)) {
+    bool builtSomething = false;
+    for (final Directory example in getExamplesForPackage(package)) {
       final String packageName =
           getRelativePosixPath(example, from: packagesDir);
 
       for (final _PlatformDetails platform in buildPlatforms) {
+        // Repo policy is that a plugin must have examples configured for all
+        // supported platforms. For packages, just log and skip any requested
+        // platform that a package doesn't have set up.
+        if (!isPlugin &&
+            !example
+                .childDirectory(platform.flutterPlatformDirectory)
+                .existsSync()) {
+          print('Skipping ${platform.label} for $packageName; not supported.');
+          continue;
+        }
+
+        builtSomething = true;
+
         String buildPlatform = platform.label;
         if (platform.label.toLowerCase() != platform.flutterBuildType) {
           buildPlatform += ' (${platform.flutterBuildType})';
@@ -143,6 +165,15 @@ class BuildExamplesCommand extends PackageLoopingCommand {
       }
     }
 
+    if (!builtSomething) {
+      if (isPlugin) {
+        errors.add('No examples found');
+      } else {
+        return PackageResult.skip(
+            'No examples found supporting requested platform(s).');
+      }
+    }
+
     return errors.isEmpty
         ? PackageResult.success()
         : PackageResult.fail(errors);
@@ -188,6 +219,11 @@ class _PlatformDetails {
   /// The `flutter build` build type.
   final String flutterBuildType;
 
+  /// The Flutter platform directory name.
+  // In practice, this is the same as the plugin platform key for all platforms.
+  // If that changes, this can be adjusted.
+  String get flutterPlatformDirectory => pluginPlatform;
+
   /// Any extra flags to pass to `flutter build`.
   final List<String> extraBuildFlags;
 }

script/tool/lib/src/common/plugin_command.dart

@@ -358,10 +358,10 @@ abstract class PluginCommand extends Command<void> {
     return entity is Directory && entity.childFile('pubspec.yaml').existsSync();
   }
 
-  /// Returns the example Dart packages contained in the specified plugin, or
-  /// an empty List, if the plugin has no examples.
-  Iterable<Directory> getExamplesForPlugin(Directory plugin) {
-    final Directory exampleFolder = plugin.childDirectory('example');
+  /// Returns the example Flutter packages contained in the specified package,
+  /// or an empty iterable if the package has no Flutter examples.
+  Iterable<Directory> getExamplesForPackage(Directory package) {
+    final Directory exampleFolder = package.childDirectory('example');
     if (!exampleFolder.existsSync()) {
       return <Directory>[];
     }

script/tool/lib/src/common/plugin_utils.dart

@@ -16,6 +16,25 @@ enum PlatformSupport {
   federated,
 }
 
+/// Returns true if [package] is a Flutter plugin.
+bool isFlutterPlugin(Directory package) {
+  try {
+    final File pubspecFile = package.childFile('pubspec.yaml');
+    final YamlMap pubspecYaml =
+        loadYaml(pubspecFile.readAsStringSync()) as YamlMap;
+    final YamlMap? flutterSection = pubspecYaml['flutter'] as YamlMap?;
+    if (flutterSection == null) {
+      return false;
+    }
+    final YamlMap? pluginSection = flutterSection['plugin'] as YamlMap?;
+    return pluginSection != null;
+  } on FileSystemException {
+    return false;
+  } on YamlException {
+    return false;
+  }
+}
+
 /// Returns whether the given directory contains a Flutter [platform] plugin.
 ///
 /// It checks this by looking for the following pattern in the pubspec:

script/tool/lib/src/drive_examples_command.dart

@@ -146,7 +146,7 @@ class DriveExamplesCommand extends PackageLoopingCommand {
     int examplesFound = 0;
     bool testsRan = false;
     final List<String> errors = <String>[];
-    for (final Directory example in getExamplesForPlugin(package)) {
+    for (final Directory example in getExamplesForPackage(package)) {
       ++examplesFound;
       final String exampleName =
           getRelativePosixPath(example, from: packagesDir);

script/tool/lib/src/list_command.dart

@@ -47,7 +47,7 @@ class ListCommand extends PluginCommand {
       case _example:
         final Stream<Directory> examples = getTargetPackages()
             .map((PackageEnumerationEntry entry) => entry.directory)
-            .expand<Directory>(getExamplesForPlugin);
+            .expand<Directory>(getExamplesForPackage);
         await for (final Directory package in examples) {
           print(package.path);
         }

script/tool/lib/src/native_test_command.dart

@@ -216,7 +216,7 @@ this command.
           });
     }
 
-    final Iterable<Directory> examples = getExamplesForPlugin(plugin);
+    final Iterable<Directory> examples = getExamplesForPackage(plugin);
 
     bool ranTests = false;
     bool failed = false;
@@ -330,7 +330,7 @@ this command.
 
     // Assume skipped until at least one test has run.
     RunState overallResult = RunState.skipped;
-    for (final Directory example in getExamplesForPlugin(plugin)) {
+    for (final Directory example in getExamplesForPackage(plugin)) {
       final String exampleName = getPackageDescription(example);
 
       if (testTarget != null) {

script/tool/lib/src/xcode_analyze_command.dart

@@ -83,7 +83,7 @@ class XcodeAnalyzeCommand extends PackageLoopingCommand {
     List<String> extraFlags = const <String>[],
   }) async {
     bool passing = true;
-    for (final Directory example in getExamplesForPlugin(plugin)) {
+    for (final Directory example in getExamplesForPackage(plugin)) {
       // Running tests and static analyzer.
       final String examplePath =
           getRelativePosixPath(example, from: plugin.parent);

script/tool/pubspec.yaml

@@ -1,7 +1,7 @@
 name: flutter_plugin_tools
 description: Productivity utils for flutter/plugins and flutter/packages
 repository: https://github.com/flutter/plugins/tree/master/script/tool
-version: 0.5.0
+version: 0.5.1+1
 
 dependencies:
   args: ^2.1.0

script/tool/test/build_examples_command_test.dart

@@ -82,6 +82,35 @@ void main() {
           ]));
     });
 
+    test('fails if a plugin has no examples', () async {
+      createFakePlugin('plugin', packagesDir,
+          examples: <String>[],
+          platformSupport: <String, PlatformSupport>{
+            kPlatformIos: PlatformSupport.inline
+          });
+
+      processRunner
+              .mockProcessesForExecutable[getFlutterCommand(mockPlatform)] =
+          <io.Process>[
+        MockProcess.failing() // flutter packages get
+      ];
+
+      Error? commandError;
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['build-examples', '--ios'], errorHandler: (Error e) {
+        commandError = e;
+      });
+
+      expect(commandError, isA<ToolExit>());
+      expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('The following packages had errors:'),
+            contains('  plugin:\n'
+                '    No examples found'),
+          ]));
+    });
+
     test('building for iOS when plugin is not set up for iOS results in no-op',
         () async {
       mockPlatform.isMacOS = true;
@@ -432,5 +461,138 @@ void main() {
                 pluginExampleDirectory.path),
           ]));
     });
+
+    test('logs skipped platforms', () async {
+      createFakePlugin('plugin', packagesDir,
+          platformSupport: <String, PlatformSupport>{
+            kPlatformAndroid: PlatformSupport.inline,
+          });
+
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['build-examples', '--apk', '--ios', '--macos']);
+
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('Skipping unsupported platform(s): iOS, macOS'),
+        ]),
+      );
+    });
+
+    group('packages', () {
+      test('builds when requested platform is supported by example', () async {
+        final Directory packageDirectory = createFakePackage(
+            'package', packagesDir, isFlutter: true, extraFiles: <String>[
+          'example/ios/Runner.xcodeproj/project.pbxproj'
+        ]);
+
+        final List<String> output = await runCapturingPrint(
+            runner, <String>['build-examples', '--ios']);
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Running for package'),
+            contains('BUILDING package/example for iOS'),
+          ]),
+        );
+
+        expect(
+            processRunner.recordedCalls,
+            orderedEquals(<ProcessCall>[
+              ProcessCall(
+                  getFlutterCommand(mockPlatform),
+                  const <String>[
+                    'build',
+                    'ios',
+                    '--no-codesign',
+                  ],
+                  packageDirectory.childDirectory('example').path),
+            ]));
+      });
+
+      test('skips non-Flutter examples', () async {
+        createFakePackage('package', packagesDir, isFlutter: false);
+
+        final List<String> output = await runCapturingPrint(
+            runner, <String>['build-examples', '--ios']);
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Running for package'),
+            contains('No examples found supporting requested platform(s).'),
+          ]),
+        );
+
+        expect(processRunner.recordedCalls, orderedEquals(<ProcessCall>[]));
+      });
+
+      test('skips when there is no example', () async {
+        createFakePackage('package', packagesDir,
+            isFlutter: true, examples: <String>[]);
+
+        final List<String> output = await runCapturingPrint(
+            runner, <String>['build-examples', '--ios']);
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Running for package'),
+            contains('No examples found supporting requested platform(s).'),
+          ]),
+        );
+
+        expect(processRunner.recordedCalls, orderedEquals(<ProcessCall>[]));
+      });
+
+      test('skip when example does not support requested platform', () async {
+        createFakePackage('package', packagesDir,
+            isFlutter: true,
+            extraFiles: <String>['example/linux/CMakeLists.txt']);
+
+        final List<String> output = await runCapturingPrint(
+            runner, <String>['build-examples', '--ios']);
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Running for package'),
+            contains('Skipping iOS for package/example; not supported.'),
+            contains('No examples found supporting requested platform(s).'),
+          ]),
+        );
+
+        expect(processRunner.recordedCalls, orderedEquals(<ProcessCall>[]));
+      });
+
+      test('logs skipped platforms when only some are supported', () async {
+        final Directory packageDirectory = createFakePackage(
+            'package', packagesDir,
+            isFlutter: true,
+            extraFiles: <String>['example/linux/CMakeLists.txt']);
+
+        final List<String> output = await runCapturingPrint(
+            runner, <String>['build-examples', '--apk', '--linux']);
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('Running for package'),
+            contains('Building for: Android, Linux'),
+            contains('Skipping Android for package/example; not supported.'),
+          ]),
+        );
+
+        expect(
+            processRunner.recordedCalls,
+            orderedEquals(<ProcessCall>[
+              ProcessCall(
+                  getFlutterCommand(mockPlatform),
+                  const <String>['build', 'linux'],
+                  packageDirectory.childDirectory('example').path),
+            ]));
+      });
+    });
   });
 }