Migrate to null safety

.travis.yml

@@ -2,7 +2,6 @@ language: dart
 
 dart:
   - dev
-  - 2.8.1
 
 dart_task:
   - test
@@ -14,9 +13,6 @@ matrix:
   - dart: dev
     dart_task:
       dartanalyzer: --fatal-infos --fatal-warnings .
-  - dart: 2.8.1
-    dart_task:
-      dartanalyzer: --fatal-warnings .
 
 branches:
   only: [master]

CHANGELOG.md

@@ -1,7 +1,8 @@
-## 1.2.1-dev
+## 2.0.0-nullsafety
 
-* Update minimum Dart SDK to `2.7.0`.
+* Migrate to null safety.
 * Fix outdated URLs in `README.md`.
+* BREAKING: Removed archive support.
 
 ## 1.2.0
 

lib/src/descriptor.dart

@@ -15,11 +15,11 @@ abstract class Descriptor {
 
   /// Creates this entry within the [parent] directory, which defaults to
   /// [sandbox].
-  Future create([String parent]);
+  Future<void> create([String? parent]);
 
   /// Validates that the physical file system under [parent] (which defaults to
   /// [sandbox]) contains an entry that matches this descriptor.
-  Future validate([String parent]);
+  Future<void> validate([String? parent]);
 
   /// Returns a human-friendly tree-style description of this descriptor.
   String describe();

lib/src/directory_descriptor.dart

@@ -52,18 +52,18 @@ class DirectoryDescriptor extends Descriptor {
           }
           // Ignore broken symlinks.
           return null;
-        }).where((path) => path != null));
+        }).whereType<Descriptor>());
   }
 
   @override
-  Future create([String parent]) async {
+  Future<void> create([String? parent]) async {
     var fullPath = p.join(parent ?? sandbox, name);
     await Directory(fullPath).create(recursive: true);
     await Future.wait(contents.map((entry) => entry.create(fullPath)));
   }
 
   @override
-  Future validate([String parent]) async {
+  Future<void> validate([String? parent]) async {
     var fullPath = p.join(parent ?? sandbox, name);
     if (!(await Directory(fullPath).exists())) {
       fail('Directory not found: "${prettyPath(fullPath)}".');
@@ -80,7 +80,7 @@ class DirectoryDescriptor extends Descriptor {
   /// The [parents] parameter should only be passed by subclasses of
   /// [DirectoryDescriptor] that are recursively calling [load]. It's the
   /// URL-format path of the directories that have been loaded so far.
-  Stream<List<int>> load(url, [String parents]) {
+  Stream<List<int>> load(url, [String? parents]) {
     String path;
     if (url is String) {
       path = url;

lib/src/file_descriptor.dart

@@ -60,7 +60,7 @@ abstract class FileDescriptor extends Descriptor {
   FileDescriptor.protected(String name) : super(name);
 
   @override
-  Future create([String parent]) async {
+  Future<void> create([String? parent]) async {
     // Create the stream before we call [File.openWrite] because it may fail
     // fast (e.g. if this is a matcher file).
     var file = File(p.join(parent ?? sandbox, name)).openWrite();
@@ -72,7 +72,7 @@ abstract class FileDescriptor extends Descriptor {
   }
 
   @override
-  Future validate([String parent]) async {
+  Future<void> validate([String? parent]) async {
     var fullPath = p.join(parent ?? sandbox, name);
     var pretty = prettyPath(fullPath);
     if (!(await File(fullPath).exists())) {
@@ -87,7 +87,7 @@ abstract class FileDescriptor extends Descriptor {
   ///
   /// The [prettyPath] is a human-friendly representation of the path to the
   /// descriptor.
-  Future _validate(String prettyPath, List<int> binaryContents);
+  FutureOr<void> _validate(String prettyPath, List<int> binaryContents);
 
   /// Reads and decodes the contents of this descriptor as a UTF-8 string.
   ///
@@ -113,8 +113,8 @@ class _BinaryFileDescriptor extends FileDescriptor {
   Stream<List<int>> readAsBytes() => Stream.fromIterable([_contents]);
 
   @override
-  Future _validate(String prettPath, List<int> actualContents) async {
-    if (const IterableEquality().equals(_contents, actualContents)) return null;
+  Future<void> _validate(String prettPath, List<int> actualContents) async {
+    if (const IterableEquality().equals(_contents, actualContents)) return;
     // TODO(nweiz): show a hex dump here if the data is small enough.
     fail('File "$prettPath" didn\'t contain the expected binary data.');
   }
@@ -134,9 +134,9 @@ class _StringFileDescriptor extends FileDescriptor {
       Stream.fromIterable([utf8.encode(_contents)]);
 
   @override
-  Future _validate(String prettyPath, List<int> actualContents) {
+  void _validate(String prettyPath, List<int> actualContents) {
     var actualContentsText = utf8.decode(actualContents);
-    if (_contents == actualContentsText) return null;
+    if (_contents == actualContentsText) return;
     fail(_textMismatchMessage(prettyPath, _contents, actualContentsText));
   }
 
@@ -194,7 +194,7 @@ class _MatcherFileDescriptor extends FileDescriptor {
       throw UnsupportedError("Matcher files can't be created or read.");
 
   @override
-  Future _validate(String prettyPath, List<int> actualContents) async {
+  Future<void> _validate(String prettyPath, List<int> actualContents) async {
     try {
       expect(
           _isBinary ? actualContents : utf8.decode(actualContents), _matcher);

lib/src/nothing_descriptor.dart

@@ -18,10 +18,10 @@ class NothingDescriptor extends Descriptor {
   NothingDescriptor(String name) : super(name);
 
   @override
-  Future create([String parent]) async {}
+  Future<void> create([String? parent]) async {}
 
   @override
-  Future validate([String parent]) async {
+  Future<void> validate([String? parent]) async {
     var fullPath = p.join(parent ?? sandbox, name);
     var pretty = prettyPath(fullPath);
     if (File(fullPath).existsSync()) {

lib/src/pattern_descriptor.dart

@@ -41,7 +41,7 @@ class PatternDescriptor extends Descriptor {
   /// in the constructor and validates the result. If exactly one succeeds,
   /// `this` is considered valid.
   @override
-  Future validate([String parent]) async {
+  Future<void> validate([String? parent]) async {
     var inSandbox = parent == null;
     parent ??= sandbox;
     var matchingEntries = await Directory(parent)
@@ -57,27 +57,30 @@ class PatternDescriptor extends Descriptor {
       fail('No entries found in $location matching $_patternDescription.');
     }
 
-    var results = await Future.wait(matchingEntries.map((entry) {
-      var basename = p.basename(entry);
-      return runZonedGuarded(() {
-        return Result.capture(Future.sync(() async {
-          await _fn(basename).validate(parent);
-          return basename;
-        }));
-      }, (_, __) {
-        // Validate may produce multiple errors, but we ignore all but the first
-        // to avoid cluttering the user with many different errors from many
-        // different un-matched entries.
-      });
-    }).toList());
+    var results = await Future.wait(matchingEntries
+        .map((entry) {
+          var basename = p.basename(entry);
+          return runZonedGuarded(() {
+            return Result.capture(Future.sync(() async {
+              await _fn(basename).validate(parent);
+              return basename;
+            }));
+          }, (_, __) {
+            // Validate may produce multiple errors, but we ignore all but the first
+            // to avoid cluttering the user with many different errors from many
+            // different un-matched entries.
+          });
+        })
+        .whereType<Future<Result<String>>>()
+        .toList());
 
     var successes = results.where((result) => result.isValue).toList();
     if (successes.isEmpty) {
       await waitAndReportErrors(results.map((result) => result.asFuture));
     } else if (successes.length > 1) {
       fail('Multiple valid entries found in $location matching '
           '$_patternDescription:\n'
-          '${bullet(successes.map((result) => result.asValue.value))}');
+          '${bullet(successes.map((result) => result.asValue!.value))}');
     }
   }
 
@@ -96,7 +99,7 @@ class PatternDescriptor extends Descriptor {
   }
 
   @override
-  Future create([String parent]) {
+  Future<void> create([String? parent]) {
     throw UnsupportedError("Pattern descriptors don't support create().");
   }
 }