blob: 2f3fbe3b6014bfa62cb8909b50fad8b083a7aa12 [file] [log] [blame]
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:yaml/yaml.dart';
import 'base/file_system.dart';
import 'base/logger.dart';
import 'base/utils.dart';
import 'project.dart';
import 'version.dart';
enum FlutterProjectType {
/// This is the default project with the user-managed host code.
/// It is different than the "module" template in that it exposes and doesn't
/// manage the platform code.
/// A List/Detail app template that follows community best practices.
/// The is a project that has managed platform host code. It is an application with
/// ephemeral .ios and .android directories that can be updated automatically.
/// This is a Flutter Dart package project. It doesn't have any native
/// components, only Dart.
/// This is a native plugin project.
/// This is an FFI native plugin project.
String flutterProjectTypeToString(FlutterProjectType? type) {
if (type == null) {
return '';
if (type == FlutterProjectType.ffiPlugin) {
return 'plugin_ffi';
return getEnumName(type);
FlutterProjectType? stringToProjectType(String value) {
FlutterProjectType? result;
for (final FlutterProjectType type in FlutterProjectType.values) {
if (value == flutterProjectTypeToString(type)) {
result = type;
return result;
/// Verifies the expected yaml keys are present in the file.
bool _validateMetadataMap(YamlMap map, Map<String, Type> validations, Logger logger) {
bool isValid = true;
for (final MapEntry<String, Object> entry in validations.entries) {
if (!map.keys.contains(entry.key)) {
isValid = false;
logger.printTrace('The key `${entry.key}` was not found');
final Object? metadataValue = map[entry.key];
if (metadataValue.runtimeType != entry.value) {
isValid = false;
logger.printTrace('The value of key `${entry.key}` in .metadata was expected to be ${entry.value} but was ${metadataValue.runtimeType}');
return isValid;
/// A wrapper around the `.metadata` file.
class FlutterProjectMetadata {
/// Creates a MigrateConfig by parsing an existing .migrate_config yaml file.
FlutterProjectMetadata(this.file, Logger logger) : _logger = logger,
migrateConfig = MigrateConfig() {
if (!file.existsSync()) {
_logger.printTrace('No .metadata file found at ${file.path}.');
// Create a default empty metadata.
Object? yamlRoot;
try {
yamlRoot = loadYaml(file.readAsStringSync());
} on YamlException {
// Handled in _validate below.
if (yamlRoot is! YamlMap) {
_logger.printTrace('.metadata file at ${file.path} was empty or malformed.');
if (_validateMetadataMap(yamlRoot, <String, Type>{'version': YamlMap}, _logger)) {
final Object? versionYamlMap = yamlRoot['version'];
if (versionYamlMap is YamlMap && _validateMetadataMap(versionYamlMap, <String, Type>{
'revision': String,
'channel': String,
}, _logger)) {
_versionRevision = versionYamlMap['revision'] as String?;
_versionChannel = versionYamlMap['channel'] as String?;
if (_validateMetadataMap(yamlRoot, <String, Type>{'project_type': String}, _logger)) {
_projectType = stringToProjectType(yamlRoot['project_type'] as String);
final Object? migrationYaml = yamlRoot['migration'];
if (migrationYaml is YamlMap) {
migrateConfig.parseYaml(migrationYaml, _logger);
/// Creates a FlutterProjectMetadata by explicitly providing all values.
required this.file,
required String? versionRevision,
required String? versionChannel,
required FlutterProjectType? projectType,
required this.migrateConfig,
required Logger logger,
}) : _logger = logger,
_versionChannel = versionChannel,
_versionRevision = versionRevision,
_projectType = projectType;
/// The name of the config file.
static const String kFileName = '.metadata';
String? _versionRevision;
String? get versionRevision => _versionRevision;
String? _versionChannel;
String? get versionChannel => _versionChannel;
FlutterProjectType? _projectType;
FlutterProjectType? get projectType => _projectType;
/// Metadata and configuration for the migrate command.
MigrateConfig migrateConfig;
final Logger _logger;
final File file;
/// Writes the .migrate_config file in the provided project directory's platform subdirectory.
/// We write the file manually instead of with a template because this
/// needs to be able to write the .migrate_config file into legacy apps.
void writeFile({File? outputFile}) {
outputFile = outputFile ?? file;
if (outputFile == null) {
// In-memory FlutterProjectMetadata instances requires an output file to
// be passed or specified in the constructor.
throw const FileSystemException('No outputFile specified to write .metadata to. Initialize with a file or provide one when writing.');
..createSync(recursive: true)
..writeAsStringSync(toString(), flush: true);
String toString() {
return '''
# This file tracks properties of this Flutter project.
# Used by Flutter tool to assess capabilities and perform upgrades etc.
# This file should be version controlled.
revision: $_versionRevision
channel: $_versionChannel
project_type: ${flutterProjectTypeToString(projectType)}
void populate({
List<SupportedPlatform>? platforms,
required Directory projectDirectory,
String? currentRevision,
String? createRevision,
bool create = true,
bool update = true,
required Logger logger,
}) {
platforms: platforms,
projectDirectory: projectDirectory,
currentRevision: currentRevision,
createRevision: createRevision,
create: create,
update: update,
logger: logger,
/// Finds the fallback revision to use when no base revision is found in the migrate config.
String getFallbackBaseRevision(Logger logger, FlutterVersion flutterVersion) {
// Use the .metadata file if it exists.
if (versionRevision != null) {
return versionRevision!;
return flutterVersion.frameworkRevision;
/// Represents the migrate command metadata section of a .metadata file.
/// This file tracks the flutter sdk git hashes of the last successful migration ('base') and
/// the version the project was created with.
/// Each platform tracks a different set of revisions because flutter create can be
/// used to add support for new platforms, so the base and create revision may not always be the same.
class MigrateConfig {
Map<SupportedPlatform, MigratePlatformConfig>? platformConfigs,
this.unmanagedFiles = kDefaultUnmanagedFiles
}) : platformConfigs = platformConfigs ?? <SupportedPlatform, MigratePlatformConfig>{};
/// A mapping of the files that are unmanaged by defult for each platform.
static const List<String> kDefaultUnmanagedFiles = <String>[
/// The metadata for each platform supported by the project.
final Map<SupportedPlatform, MigratePlatformConfig> platformConfigs;
/// A list of paths relative to this file the migrate tool should ignore.
/// These files are typically user-owned files that should not be changed.
List<String> unmanagedFiles;
bool get isEmpty => platformConfigs.isEmpty && (unmanagedFiles.isEmpty || unmanagedFiles == kDefaultUnmanagedFiles);
/// Parses the project for all supported platforms and populates the [MigrateConfig]
/// to reflect the project.
void populate({
List<SupportedPlatform>? platforms,
required Directory projectDirectory,
String? currentRevision,
String? createRevision,
bool create = true,
bool update = true,
required Logger logger,
}) {
final FlutterProject flutterProject = FlutterProject.fromDirectory(projectDirectory);
platforms ??= flutterProject.getSupportedPlatforms(includeRoot: true);
for (final SupportedPlatform platform in platforms) {
if (platformConfigs.containsKey(platform)) {
if (update) {
platformConfigs[platform]!.baseRevision = currentRevision;
} else {
if (create) {
platformConfigs[platform] = MigratePlatformConfig(platform: platform, createRevision: createRevision, baseRevision: currentRevision);
/// Returns the string that should be written to the .metadata file.
String getOutputFileString() {
String unmanagedFilesString = '';
for (final String path in unmanagedFiles) {
unmanagedFilesString += "\n - '$path'";
String platformsString = '';
for (final MapEntry<SupportedPlatform, MigratePlatformConfig> entry in platformConfigs.entries) {
platformsString += '\n - platform: ${entry.key.toString().split('.').last}\n create_revision: ${entry.value.createRevision == null ? 'null' : "${entry.value.createRevision}"}\n base_revision: ${entry.value.baseRevision == null ? 'null' : "${entry.value.baseRevision}"}';
return isEmpty ? '' : '''
# Tracks metadata for the flutter migrate command
# User provided section
# List of Local paths (relative to this file) that should be
# ignored by the migrate tool.
# Files that are not part of the templates will be ignored by default.
/// Parses and validates the `migration` section of the .metadata file.
void parseYaml(YamlMap map, Logger logger) {
final Object? platformsYaml = map['platforms'];
if (_validateMetadataMap(map, <String, Type>{'platforms': YamlList}, logger)) {
if (platformsYaml is YamlList && platformsYaml.isNotEmpty) {
for (final YamlMap platformYamlMap in platformsYaml.whereType<YamlMap>()) {
if (_validateMetadataMap(platformYamlMap, <String, Type>{
'platform': String,
'create_revision': String,
'base_revision': String,
}, logger)) {
final SupportedPlatform platformValue = SupportedPlatform.values.firstWhere(
(SupportedPlatform val) => val.toString() == 'SupportedPlatform.${platformYamlMap['platform'] as String}'
platformConfigs[platformValue] = MigratePlatformConfig(
platform: platformValue,
createRevision: platformYamlMap['create_revision'] as String?,
baseRevision: platformYamlMap['base_revision'] as String?,
} else {
// malformed platform entry
if (_validateMetadataMap(map, <String, Type>{'unmanaged_files': YamlList}, logger)) {
final Object? unmanagedFilesYaml = map['unmanaged_files'];
if (unmanagedFilesYaml is YamlList && unmanagedFilesYaml.isNotEmpty) {
unmanagedFiles = List<String>.from(unmanagedFilesYaml.value.cast<String>());
/// Holds the revisions for a single platform for use by the flutter migrate command.
class MigratePlatformConfig {
required this.platform,
/// The platform this config describes.
SupportedPlatform platform;
/// The Flutter SDK revision this platform was created by.
/// Null if the initial create git revision is unknown.
final String? createRevision;
/// The Flutter SDK revision this platform was last migrated by.
/// Null if the project was never migrated or the revision is unknown.
String? baseRevision;
bool equals(MigratePlatformConfig other) {
return platform == other.platform &&
createRevision == other.createRevision &&
baseRevision == other.baseRevision;