Remove or replace unnecessary usages of late (#4512)

lib/src/command/add.dart

@@ -203,7 +203,7 @@ Specify multiple sdk packages with descriptors.''');
       resolutionPubspec = await _addPackageToPubspec(resolutionPubspec, update);
     }
 
-    late SolveResult solveResult;
+    final SolveResult solveResult;
 
     try {
       /// Use [SolveType.UPGRADE] to solve for the highest version of [package]
@@ -520,7 +520,7 @@ Specify multiple sdk packages with descriptors.''');
     }
 
     /// The package to be added.
-    late final PackageRef ref;
+    final PackageRef ref;
     final path = argResults.path;
     if (argResults.hasGitOptions) {
       final gitUrl = argResults.gitUrl;

lib/src/entrypoint.dart

@@ -240,7 +240,7 @@ See $workspacesDocUrl for more information.''',
           '"pub" version, please run "$topLevelProgram pub get".');
     }
 
-    late String packageConfigRaw;
+    final String packageConfigRaw;
     try {
       packageConfigRaw = readTextFile(packageConfigPath);
     } on FileException {
@@ -249,7 +249,7 @@ See $workspacesDocUrl for more information.''',
         'please run "$topLevelProgram pub get".',
       );
     }
-    late PackageConfig result;
+    final PackageConfig result;
     try {
       result = PackageConfig.fromJson(
         json.decode(packageConfigRaw) as Object?,
@@ -297,7 +297,7 @@ See $workspacesDocUrl for more information.''',
 
   /// The path to the entrypoint's ".dart_tool/package_config.json" file
   /// relative to the current working directory .
-  late String packageConfigPath = p.relative(
+  late final String packageConfigPath = p.relative(
     p.normalize(p.join(workspaceRoot.dir, '.dart_tool', 'package_config.json')),
   );
 
@@ -434,19 +434,21 @@ See $workspacesDocUrl for more information.''',
     VersionConstraint? entrypointSdkConstraint,
   }) async {
     final entries = <PackageConfigEntry>[];
-    late final relativeFromPath = p.join(workspaceRoot.dir, '.dart_tool');
-    for (final name in ordered(lockFile.packages.keys)) {
-      final id = lockFile.packages[name]!;
-      final rootPath = cache.getDirectory(id, relativeFrom: relativeFromPath);
-      final pubspec = await cache.describe(id);
-      entries.add(
-        PackageConfigEntry(
-          name: name,
-          rootUri: p.toUri(rootPath),
-          packageUri: p.toUri('lib/'),
-          languageVersion: pubspec.languageVersion,
-        ),
-      );
+    if (lockFile.packages.isNotEmpty) {
+      final relativeFromPath = p.join(workspaceRoot.dir, '.dart_tool');
+      for (final name in ordered(lockFile.packages.keys)) {
+        final id = lockFile.packages[name]!;
+        final rootPath = cache.getDirectory(id, relativeFrom: relativeFromPath);
+        final pubspec = await cache.describe(id);
+        entries.add(
+          PackageConfigEntry(
+            name: name,
+            rootUri: p.toUri(rootPath),
+            packageUri: p.toUri('lib/'),
+            languageVersion: pubspec.languageVersion,
+          ),
+        );
+      }
     }
 
     if (!isCachedGlobal) {
@@ -1016,8 +1018,8 @@ To update `$lockFilePath` run `$topLevelProgram pub get`$suffix without
           rootDir = parent;
           break;
         }
-        final potentialPubspacPath = p.join(parent, 'pubspec.yaml');
-        if (tryStatFile(potentialPubspacPath) == null) {
+        final potentialPubspecPath = p.join(parent, 'pubspec.yaml');
+        if (tryStatFile(potentialPubspecPath) == null) {
           // No package at [parent] continue to next dir.
           continue;
         }
@@ -1029,8 +1031,8 @@ To update `$lockFilePath` run `$topLevelProgram pub get`$suffix without
         final workspaceRefText = tryReadTextFile(potentialWorkspaceRefPath);
         if (workspaceRefText == null) {
           log.fine(
-            '`$potentialPubspacPath` exists without corresponding '
-            '`$potentialPubspacPath` or `$potentialWorkspaceRefPath`.',
+            '`$potentialPubspecPath` exists without corresponding '
+            '`$potentialPubspecPath` or `$potentialWorkspaceRefPath`.',
           );
           return null;
         } else {
@@ -1093,7 +1095,7 @@ To update `$lockFilePath` run `$topLevelProgram pub get`$suffix without
         return null;
       }
       final lockFilePath = p.normalize(p.join(rootDir, 'pubspec.lock'));
-      late final packageConfig = _loadPackageConfig(packageConfigPath);
+      final packageConfig = _loadPackageConfig(packageConfigPath);
       if (p.isWithin(cache.rootDir, packageConfigPath)) {
         // We always consider a global package (inside the cache) up-to-date.
         return (packageConfig, rootDir);

lib/src/error_group.dart

@@ -44,15 +44,15 @@ class ErrorGroup {
   ///
   /// We need to be able to access it internally as an [_ErrorGroupFuture] so
   /// we can check if it has listeners and signal errors on it.
-  late _ErrorGroupFuture _done;
+  late final _ErrorGroupFuture<void> _done;
 
   /// Returns a [Future] that completes successfully when all members of `this`
   /// are complete, or with an error if any member receives an error.
   ///
   /// This [Future] is effectively in the group in that an error on it won't be
   /// passed to the top-level error handler unless no members of the group have
   /// listeners attached.
-  Future get done => _done;
+  Future<void> get done => _done;
 
   /// Creates a new group with no members.
   ErrorGroup() {
@@ -257,17 +257,17 @@ class _ErrorGroupStream<T> extends Stream<T> {
   var _isDone = false;
 
   /// The underlying [StreamController] for `this`.
-  late final StreamController<T> _controller;
+  final StreamController<T> _controller;
 
   /// The controller's [Stream].
   ///
   /// May be different than `_controller.stream` if the wrapped stream is a
   /// broadcasting stream.
-  late Stream<T> _stream;
+  late final Stream<T> _stream;
 
   /// The [StreamSubscription] that connects the wrapped [Stream] to
   /// [_controller].
-  late StreamSubscription<T> _subscription;
+  late final StreamSubscription<T> _subscription;
 
   /// Whether `this` has any listeners.
   bool get _hasListeners => _controller.hasListener;

lib/src/executable.dart

@@ -351,8 +351,8 @@ Future<DartExecutableWithPackageConfig> getExecutableForCommand(
       CommandResolutionIssue.fileNotFound,
     );
   }
-  late final String command;
-  String package;
+  final String command;
+  final String package;
   if (descriptor.contains(':')) {
     final parts = descriptor.split(':');
     if (parts.length > 2) {
@@ -361,12 +361,11 @@ Future<DartExecutableWithPackageConfig> getExecutableForCommand(
         CommandResolutionIssue.parseError,
       );
     }
-    package = parts[0];
-    if (package.isEmpty) package = rootPackageName;
+    final packageName = parts[0];
+    package = packageName.isNotEmpty ? packageName : rootPackageName;
     command = parts[1];
   } else {
-    package = descriptor;
-    if (package.isEmpty) package = rootPackageName;
+    package = descriptor.isNotEmpty ? descriptor : rootPackageName;
     command = package;
   }
 

lib/src/global_packages.dart

@@ -322,7 +322,7 @@ To recompile executables, first run `$topLevelProgram pub global deactivate $nam
 
   /// Shows the user the currently active package with [name], if any.
   LockFile? _describeActive(String name, SystemCache cache) {
-    late final LockFile lockFile;
+    final LockFile lockFile;
     try {
       lockFile = LockFile.load(_getLockFilePath(name), cache.sources);
     } on IOException {
@@ -380,7 +380,7 @@ To recompile executables, first run `$topLevelProgram pub global deactivate $nam
   /// Returns an [Entrypoint] loaded with the active package if found.
   Future<Entrypoint> find(String name) async {
     final lockFilePath = _getLockFilePath(name);
-    late final LockFile lockFile;
+    final LockFile lockFile;
     try {
       lockFile = LockFile.load(lockFilePath, cache.sources);
     } on IOException {
@@ -861,7 +861,7 @@ Try reactivating the package.
     final pubInvocation =
         runningFromTest ? Platform.script.toFilePath() : 'pub';
 
-    late String binstub;
+    final String binstub;
     // We need an absolute path since relative ones won't be relative to the
     // right directory when the user runs this.
     snapshot = p.absolute(snapshot);

lib/src/io.dart

@@ -950,26 +950,11 @@ class PubProcess {
   /// The underlying `dart:io` [Process].
   final Process _process;
 
-  /// The mutable field for [stdin].
-  late EventSink<List<int>> _stdin;
-
-  /// The mutable field for [stdinClosed].
-  late Future _stdinClosed;
-
-  /// The mutable field for [stdout].
-  late ByteStream _stdout;
-
-  /// The mutable field for [stderr].
-  late ByteStream _stderr;
-
-  /// The mutable field for [exitCode].
-  late Future<int> _exitCode;
-
   /// The sink used for passing data to the process's standard input stream.
   ///
   /// Errors on this stream are surfaced through [stdinClosed], [stdout],
   /// [stderr], and [exitCode], which are all members of an [ErrorGroup].
-  EventSink<List<int>> get stdin => _stdin;
+  final EventSink<List<int>> stdin;
 
   // TODO(nweiz): write some more sophisticated Future machinery so that this
   // doesn't surface errors from the other streams/futures, but still passes its
@@ -981,44 +966,61 @@ class PubProcess {
   /// This is in an [ErrorGroup] with [stdout], [stderr], and [exitCode], so any
   /// error in process will be passed to it, but won't reach the top-level error
   /// handler unless nothing has handled it.
-  Future get stdinClosed => _stdinClosed;
+  final Future stdinClosed;
 
   /// The process's standard output stream.
   ///
   /// This is in an [ErrorGroup] with [stdinClosed], [stderr], and [exitCode],
   /// so any error in process will be passed to it, but won't reach the
   /// top-level error handler unless nothing has handled it.
-  ByteStream get stdout => _stdout;
+  final ByteStream stdout;
 
   /// The process's standard error stream.
   ///
   /// This is in an [ErrorGroup] with [stdinClosed], [stdout], and [exitCode],
   /// so any error in process will be passed to it, but won't reach the
   /// top-level error handler unless nothing has handled it.
-  ByteStream get stderr => _stderr;
+  final ByteStream stderr;
 
   /// A [Future] that will complete to the process's exit code once the process
   /// has finished running.
   ///
   /// This is in an [ErrorGroup] with [stdinClosed], [stdout], and [stderr], so
   /// any error in process will be passed to it, but won't reach the top-level
   /// error handler unless nothing has handled it.
-  Future<int> get exitCode => _exitCode;
+  final Future<int> exitCode;
+
+  PubProcess._(
+    this._process, {
+    required this.stdin,
+    required this.stdinClosed,
+    required this.stdout,
+    required this.stderr,
+    required this.exitCode,
+  });
 
   /// Creates a new [PubProcess] wrapping [process].
-  PubProcess(Process process) : _process = process {
+  factory PubProcess(Process process) {
     final errorGroup = ErrorGroup();
 
     final (consumerSink, done) = _consumerToSink(process.stdin);
-    _stdin = consumerSink;
-    _stdinClosed = errorGroup.registerFuture(done);
+    final stdinClosed = errorGroup.registerFuture(done);
 
-    _stdout = ByteStream(errorGroup.registerStream(process.stdout));
-    _stderr = ByteStream(errorGroup.registerStream(process.stderr));
+    final stdout = ByteStream(errorGroup.registerStream(process.stdout));
+    final stderr = ByteStream(errorGroup.registerStream(process.stderr));
 
     final exitCodeCompleter = Completer<int>();
-    _exitCode = errorGroup.registerFuture(exitCodeCompleter.future);
-    _process.exitCode.then(exitCodeCompleter.complete);
+    final exitCode = errorGroup.registerFuture(exitCodeCompleter.future);
+    process.exitCode.then(exitCodeCompleter.complete);
+
+    return PubProcess._(
+      process,
+      stdin: consumerSink,
+      stdinClosed: stdinClosed,
+      stdout: stdout,
+      stderr: stderr,
+      exitCode: exitCode,
+    );
   }
 
   /// Sends [signal] to the underlying process.

lib/src/lock_file.dart

@@ -22,7 +22,7 @@ class LockFile {
 
   /// The intersections of all SDK constraints for all locked packages, indexed
   /// by SDK identifier.
-  Map<String, SdkConstraint> sdkConstraints;
+  final Map<String, SdkConstraint> sdkConstraints;
 
   /// Dependency names that appeared in the root package's `dependencies`
   /// section.

lib/src/package.dart

@@ -38,7 +38,7 @@ class Package {
   ///
   /// If [dir] is just a parent directory like ../.. it gets replaced with
   /// the absolute dir.
-  late String presentationDir =
+  late final String presentationDir =
       p.isWithin(dir, '.') ? p.normalize(p.absolute(dir)) : dir;
 
   /// The name of the package.

lib/src/pubspec.dart

@@ -425,7 +425,7 @@ environment:
     Uri? overridesLocation,
     required Description containingDescription,
   }) {
-    late final YamlMap pubspecMap;
+    final YamlMap pubspecMap;
     YamlMap? overridesFileMap;
     try {
       pubspecMap = _ensureMap(loadYamlNode(contents, sourceUrl: location));

lib/src/source/hosted.dart

@@ -1311,7 +1311,7 @@ class HostedSource extends CachedSource {
     return (await Future.wait(
       listDir(rootDir).map((serverDir) async {
         final directory = p.basename(serverDir);
-        late final String url;
+        final String url;
         try {
           url = _directoryToUrl(directory);
         } on FormatException {
@@ -1493,13 +1493,13 @@ class HostedSource extends CachedSource {
         versions.firstWhereOrNull((i) => i.version == id.version);
     final packageName = id.name;
     final version = id.version;
-    late final Uint8List contentHash;
     if (versionInfo == null) {
       throw PackageNotFoundException(
         'Package $packageName has no version $version',
       );
     }
 
+    late final Uint8List contentHash;
     final archiveUrl = versionInfo.archiveUrl;
     log.io('Get package from $archiveUrl.');
     log.fine('Downloading ${log.bold(id.name)} ${id.version}...');
@@ -1626,7 +1626,7 @@ See $contentHashesDocumentationUrl.
   ) async {
     // Extract to a temp-folder and do atomic rename to preserve the integrity
     // of the cache.
-    late final Uint8List contentHash;
+    final Uint8List contentHash;
 
     final tempDir = cache.createTempDir();
     final PackageId id;

lib/src/system_cache.dart

@@ -67,10 +67,9 @@ Consider setting the `PUB_CACHE` variable manually.
   })();
 
   /// The available sources.
-  late final _sources = Map<String, Source>.fromIterable(
-    [hosted, git, path, sdk],
-    key: (source) => (source as Source).name,
-  );
+  late final _sources = {
+    for (final source in [hosted, git, path, sdk]) source.name: source,
+  };
 
   Source sources(String? name) {
     return name == null