WIP: Migrate to nnbd

analysis_options.yaml

@@ -8,6 +8,8 @@ analyzer:
   errors:
     invalid_use_of_protected_member: error
     always_declare_return_types: error 
+  enable-experiment:
+    - non-nullable
 linter:
   rules:
     - always_declare_return_types

lib/dartx.dart

@@ -9,7 +9,6 @@ import 'dart:typed_data';
 import 'package:characters/characters.dart';
 import 'package:collection/collection.dart' hide DelegatingList;
 import 'package:crypto/crypto.dart' as crypto;
-import 'package:meta/meta.dart';
 
 export 'package:time/time.dart';
 export 'package:characters/characters.dart';

lib/src/comparable.dart

@@ -13,7 +13,7 @@ extension ComparableX<T extends Comparable<T>> on T {
   /// @return this value if it's in the range, or [minimumValue]
   /// if this value is less than [minimumValue],
   /// or [maximumValue] if this value is greater than [maximumValue].
-  T coerceIn(T minimumValue, [T maximumValue]) {
+  T coerceIn(T minimumValue, [T? maximumValue]) {
     if (maximumValue != null && minimumValue > maximumValue) {
       throw ArgumentError('Cannot coerce value to an empty range: '
           'maximum $maximumValue is less than minimum $minimumValue.');

lib/src/io/directory.dart

@@ -2,12 +2,12 @@ part of dartx_io;
 
 extension DirectoryX on Directory {
   Directory subdir(String part1,
-      [String part2,
-      String part3,
-      String part4,
-      String part5,
-      String part6,
-      String part7]) {
+      [String? part2,
+      String? part3,
+      String? part4,
+      String? part5,
+      String? part6,
+      String? part7]) {
     return Directory(
       path_helper.join(path, part1, part2, part3, part4, part5, part6, part7),
     );
@@ -22,7 +22,7 @@ extension DirectoryX on Directory {
   /// * If `this` and [target] are canonically the same, no operation occurs.
   ///
   /// Returns a future that completes when complete.
-  Future<Null> copyRecursively(Directory target) async {
+  Future<void> copyRecursively(Directory target) async {
     if (path_helper.canonicalize(path) ==
         path_helper.canonicalize(target.path)) {
       return;

lib/src/io/file.dart

@@ -21,7 +21,7 @@ extension FileX on File {
   /// This functions passes the byte buffer to the [action] function.
   ///
   /// You can use this function for huge files.
-  Future<Null> forEachBlock(
+  Future<void> forEachBlock(
       int blockSize, void Function(Uint8List buffer) action) async {
     var raf = await open(mode: FileMode.read);
     while (true) {