Migrate pkg/status_file to primary constructors and new constructor syntax.

Unlike my previous couple of CLs, I went ahead here and also migrated
most of the classes to use primary constructors since so many of them
were small and well suited for it.

In the process, I found and fixed one bug in the assist to convert to a
primary constructor:

https://dart-review.googlesource.com/c/sdk/+/506760

So I guess this CL has already paid its way. :)

Change-Id: I9b7d08e27f4ddce3f19127aaf4f14fe627b75dab
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/506743
Reviewed-by: Paul Berry <paulberry@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>

pkg/status_file/analysis_options.yaml

@@ -8,3 +8,7 @@ analyzer:
   errors:
     # Allow having TODOs in the code
     todo: ignore
+linter:
+  rules:
+    - unnecessary_const_in_enum_constructor
+    - unnecessary_type_name_in_constructor

pkg/status_file/lib/canonical_status_file.dart

@@ -74,19 +74,19 @@ class StatusFile {
 
   /// Constructor for creating a new [StatusFile]. Will not create the default
   /// section that status files have.
-  StatusFile(this.path);
+  new(this.path);
 
   /// Reads and parses the status file at [path].
   ///
   /// Throws a [SyntaxError] if the file could not be parsed.
-  StatusFile.read(this.path) {
+  new read(this.path) {
     _parse(File(path).readAsLinesSync());
   }
 
   /// Parses lines of strings coming from a status file at [path].
   ///
   /// Throws a [SyntaxError] if the file could not be parsed.
-  StatusFile.parse(this.path, List<String> lines) {
+  new parse(this.path, List<String> lines) {
     _parse(lines.map((line) => line.trim()).toList());
   }
 
@@ -305,27 +305,26 @@ class StatusFile {
 ///
 /// Contains the condition from the header that begins the section, then all of
 /// the entries within the section.
-class StatusSection {
+class StatusSection(
   /// The expression that determines when this section is applied.
   ///
   /// Will be [Expression.always] for paths that appear before any section
   /// header in the file. In that case, the section always applies.
-  final Expression condition;
+  final Expression condition,
 
   /// The one-based line number where the section appears in the file.
-  final int lineNumber;
+  final int lineNumber,
 
+  final List<Entry> sectionHeaderComments,
+) {
   /// Collection of all comment and status line entries.
   final List<Entry> entries = [];
-  final List<Entry> sectionHeaderComments;
 
   /// Returns true if this section should apply in the given [environment].
   bool isEnabled(Environment environment) => condition.evaluate(environment);
 
   bool isEmpty() => !entries.any((entry) => entry is StatusEntry);
 
-  StatusSection(this.condition, this.lineNumber, this.sectionHeaderComments);
-
   @override
   String toString() {
     var buffer = StringBuffer();
@@ -338,11 +337,7 @@ class StatusSection {
   }
 }
 
-class Comment {
-  final String _comment;
-
-  Comment(this._comment);
-
+class Comment(final String _comment) {
   /// Returns the issue number embedded in [comment] or `null` if there is none.
   int? issueNumber(String comment) {
     var match = _issuePattern.firstMatch(comment);
@@ -351,32 +346,20 @@ class Comment {
   }
 
   @override
-  String toString() {
-    return _comment;
-  }
+  String toString() => _comment;
 }
 
-abstract class Entry {
+abstract class Entry(
   /// The one-based line number where the entry appears in the file.
-  final int lineNumber;
-
-  Entry(this.lineNumber);
-}
-
-class EmptyEntry extends Entry {
-  EmptyEntry(super.lineNumber);
+  final int lineNumber,
+);
 
+class EmptyEntry(super.lineNumber) extends Entry {
   @override
-  String toString() {
-    return "";
-  }
+  String toString() => '';
 }
 
-class CommentEntry extends Entry {
-  final Comment comment;
-
-  CommentEntry(super.lineNumber, this.comment);
-
+class CommentEntry(super.lineNumber, final Comment comment) extends Entry {
   @override
   String toString() {
     return comment.toString();
@@ -384,13 +367,12 @@ class CommentEntry extends Entry {
 }
 
 /// Describes the test status of the file or files at a given path.
-class StatusEntry extends Entry {
-  final String path;
-  final List<Expectation> expectations;
-  final Comment? comment;
-
-  StatusEntry(this.path, super.lineNumber, this.expectations, this.comment);
-
+class StatusEntry(
+  final String path,
+  super.lineNumber,
+  final List<Expectation> expectations,
+  final Comment? comment,
+) extends Entry {
   @override
   String toString() {
     return comment == null

pkg/status_file/lib/expectation.dart

@@ -3,7 +3,11 @@
 // BSD-style license that can be found in the LICENSE file.
 
 /// The possible outcomes from running a test.
-class Expectation {
+class Expectation._(
+  final String _name, {
+  final Expectation? _group,
+  bool isMeta = false,
+}) {
   /// The test completed normally and did what it intended to do.
   static final Expectation pass = Expectation._('Pass');
 
@@ -234,14 +238,8 @@ class Expectation {
     return expectation;
   }
 
-  final String _name;
-  final Expectation? _group;
-
   /// Whether this expectation is a test outcome. If not, it's a "meta marker".
-  final bool isOutcome;
-
-  Expectation._(this._name, {this._group, bool isMeta = false})
-    : isOutcome = !isMeta;
+  final bool isOutcome = !isMeta;
 
   bool canBeOutcomeOf(Expectation expectation) {
     Expectation? outcome = this;

pkg/status_file/lib/src/disjunctive.dart

@@ -143,12 +143,10 @@ List<Expression>? _satisfiableMinTerms(Expression expression) {
 /// [variables] are assigned a value bases on the [configuration]. This
 /// environment can then be used to evaluate the corresponding expression from
 /// which the [variables] was found.
-class TruthTableEnvironment extends Environment {
-  final List<Expression> variables;
+class TruthTableEnvironment(final List<Expression> variables)
+    extends Environment {
   int configuration = -1;
 
-  TruthTableEnvironment(this.variables);
-
   void setConfiguration(int configuration) {
     this.configuration = configuration;
   }

pkg/status_file/lib/src/expression.dart

@@ -8,7 +8,7 @@ import 'dart:math' as math;
 import '../environment.dart';
 
 /// A parsed Boolean expression AST.
-abstract class Expression implements Comparable<Expression> {
+abstract class const Expression() implements Comparable<Expression> {
   /// An expression that always evaluates to true.
   ///
   /// Used for the section at the top of a status file with no expression.
@@ -31,8 +31,6 @@ abstract class Expression implements Comparable<Expression> {
   static Expression parse(String expression) =>
       _ExpressionParser(expression).parse();
 
-  const Expression();
-
   /// Validates that this expression does not contain any invalid uses of
   /// variables.
   ///
@@ -97,11 +95,7 @@ class _Token {
 }
 
 /// A reference to a variable.
-class Variable {
-  final String name;
-
-  Variable(this.name);
-
+class Variable(final String name) {
   String lookup(Environment environment) {
     var value = environment.lookUp(name);
     if (value == null) {
@@ -125,9 +119,7 @@ class Variable {
 ///
 /// Used for the implicit section at the top of a status file that always
 /// matches.
-class _AlwaysExpression extends Expression {
-  const _AlwaysExpression();
-
+class const _AlwaysExpression() extends Expression {
   @override
   int _compareToMyType(covariant _AlwaysExpression other) => 0;
 
@@ -149,13 +141,11 @@ class _AlwaysExpression extends Expression {
 /// $variable == someValue
 /// ```
 /// Negate the result if [negate] is true.
-class ComparisonExpression extends Expression {
-  final Variable left;
-  final String right;
-  final bool negate;
-
-  ComparisonExpression(this.left, this.right, this.negate);
-
+class ComparisonExpression(
+  final Variable left,
+  final String right,
+  final bool negate,
+) extends Expression {
   @override
   void validate(Environment environment, List<String> errors) {
     environment.validate(left.name, right, errors);
@@ -217,12 +207,8 @@ class ComparisonExpression extends Expression {
 /// ```
 ///     $variable != true
 /// ```
-class VariableExpression extends Expression {
-  final Variable variable;
-  final bool negate;
-
-  VariableExpression(this.variable, {this.negate = false});
-
+class VariableExpression(final Variable variable, {final bool negate = false})
+    extends Expression {
   @override
   void validate(Environment environment, List<String> errors) {
     // It must be a Boolean, so it should allow either Boolean value.
@@ -254,16 +240,13 @@ class VariableExpression extends Expression {
 }
 
 /// A logical `||` or `&&` expression.
-class LogicExpression extends Expression {
+class LogicExpression(
   /// The operator, `||` or `&&`.
-  final String op;
-
-  final List<Expression> operands;
-
-  LogicExpression(this.op, this.operands);
-
-  LogicExpression.and(this.operands) : op = _Token.and;
-  LogicExpression.or(this.operands) : op = _Token.or;
+  final String op,
+  final List<Expression> operands,
+) extends Expression {
+  new and(List<Expression> operands) : this(_Token.and, operands);
+  new or(List<Expression> operands) : this(_Token.or, operands);
 
   bool get isAnd => op == _Token.and;
   bool get isOr => op == _Token.or;
@@ -350,10 +333,8 @@ class LogicExpression extends Expression {
 }
 
 /// Parser for Boolean expressions in a .status file for Dart.
-class _ExpressionParser {
-  final _Scanner _scanner;
-
-  _ExpressionParser(String expression) : _scanner = _Scanner(expression);
+class _ExpressionParser(String expression) {
+  final _Scanner _scanner = _Scanner(expression);
 
   Expression parse() {
     var expression = _parseOr();
@@ -442,7 +423,7 @@ class _ExpressionParser {
 }
 
 /// An iterator that allows peeking at the current token.
-class _Scanner {
+class _Scanner(String expression) {
   /// Tokens are "(", ")", "$", "&&", "||", "!", ==", "!=", and (maximal) \w+.
   static final _testPattern = RegExp(r"^(?:[()$\w\s]|&&|\|\||==|!=?)+$");
   static final _tokenPattern = RegExp(r"[()$]|&&|\|\||==|!=?|\w+");
@@ -454,11 +435,11 @@ class _Scanner {
   static final _identifierPattern = RegExp(r"^\w");
 
   /// The token strings being iterated.
-  final Iterator<String> tokenIterator;
+  final Iterator<String> tokenIterator = tokenize(expression).iterator;
 
   String? current;
 
-  _Scanner(String expression) : tokenIterator = tokenize(expression).iterator {
+  this {
     advance();
   }
 

pkg/status_file/lib/status_file.dart

@@ -49,12 +49,12 @@ class StatusFile {
 
   int _lineCount = 0;
 
-  StatusFile(this.path);
+  new(this.path);
 
   /// Parses the status file at [path].
   ///
   /// Throws a [SyntaxError] if the file could not be parsed.
-  StatusFile.read(this.path) {
+  new read(this.path) {
     var lines = File(path).readAsLinesSync();
     _comments.length = lines.length + 1;
 
@@ -266,7 +266,7 @@ class StatusSection {
   /// Returns true if this section should apply in the given [environment].
   bool isEnabled(Environment environment) => condition.evaluate(environment);
 
-  StatusSection(this.condition, this.lineNumber);
+  new(this.condition, this.lineNumber);
 }
 
 /// Describes the test status of the file or files at a given path.
@@ -279,7 +279,7 @@ class StatusEntry {
   final List<Expectation> expectations;
   final int? issue;
 
-  StatusEntry(this.path, this.lineNumber, this.expectations, this.issue);
+  new(this.path, this.lineNumber, this.expectations, this.issue);
 }
 
 /// Error thrown when a parse or validation error occurs in a [StatusFile].
@@ -290,7 +290,7 @@ class SyntaxError implements Exception {
   final String message;
   final List<String>? errors;
 
-  SyntaxError(this.file, this.lineNumber, this.line, this.message, this.errors);
+  new(this.file, this.lineNumber, this.line, this.message, this.errors);
 
   @override
   String toString() {

pkg/status_file/lib/status_file_linter.dart

@@ -7,15 +7,9 @@ import 'dart:math' as math;
 import 'package:status_file/canonical_status_file.dart';
 import 'package:status_file/status_file_entries_file_checker.dart';
 
-class LintingError {
-  final int lineNumber;
-  final String message;
-  LintingError(this.lineNumber, this.message);
-
+class LintingError(final int lineNumber, final String message) {
   @override
-  String toString() {
-    return "Error at line $lineNumber: $message";
-  }
+  String toString() => "Error at line $lineNumber: $message";
 }
 
 /// Main function to check a status file for linting errors.
@@ -268,8 +262,4 @@ ListNotEqualWitness<T>? _findNotEqualWitness<T>(List<T> first, List<T> second) {
   return null;
 }
 
-class ListNotEqualWitness<T> {
-  final T? first;
-  final T? second;
-  ListNotEqualWitness(this.first, this.second);
-}
+class ListNotEqualWitness<T>(final T? first, final T? second);

pkg/status_file/pubspec.yaml

@@ -3,7 +3,7 @@ name: status_file
 publish_to: none
 
 environment:
-  sdk: '^3.12.0-0'
+  sdk: '^3.13.0-0'
 
 resolution: workspace
 

pkg/status_file/test/status_expression_test.dart

@@ -10,7 +10,7 @@ import "package:status_file/src/expression.dart";
 class TestEnvironment implements Environment {
   final Map<String, String> _values;
 
-  TestEnvironment(this._values);
+  new(this._values);
 
   @override
   void validate(String name, String value, List<String> errors) {