Reapply "Move the linter core to the analyzer package"

pkg/analyzer/lib/src/lint/linter.dart

Index: pkg/analyzer/lib/src/lint/linter.dart
diff --git a/pkg/analyzer/lib/src/lint/linter.dart b/pkg/analyzer/lib/src/lint/linter.dart
new file mode 100644
index 0000000000000000000000000000000000000000..5706f35ea8d26f8d5198b2c6bea474b33e6a6250
--- /dev/null
+++ b/pkg/analyzer/lib/src/lint/linter.dart
@@ -0,0 +1,429 @@
+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:io';
+
+import 'package:analyzer/analyzer.dart';
+import 'package:analyzer/dart/ast/token.dart';
+import 'package:analyzer/src/generated/engine.dart'
+    show AnalysisErrorInfo, AnalysisErrorInfoImpl, Logger;
+import 'package:analyzer/src/generated/java_engine.dart' show CaughtException;
+import 'package:analyzer/src/generated/source.dart' show LineInfo;
+import 'package:analyzer/src/generated/source_io.dart';
+import 'package:analyzer/src/lint/analysis.dart';
+import 'package:analyzer/src/lint/config.dart';
+import 'package:analyzer/src/lint/io.dart';
+import 'package:analyzer/src/lint/project.dart';
+import 'package:analyzer/src/lint/pub.dart';
+import 'package:analyzer/src/lint/registry.dart';
+import 'package:analyzer/src/services/lint.dart' show Linter;
+import 'package:glob/glob.dart';
+import 'package:path/path.dart' as p;
+
+typedef Printer(String msg);
+
+/// Describes a String in valid camel case format.
+class CamelCaseString {
+  static final _camelCaseMatcher = new RegExp(r'[A-Z][a-z]*');
+  static final _camelCaseTester = new RegExp(r'^([_$]*)([A-Z?$]+[a-z0-9]*)+$');
+
+  final String value;
+  CamelCaseString(this.value) {
+    if (!isCamelCase(value)) {
+      throw new ArgumentError('$value is not CamelCase');
+    }
+  }
+
+  String get humanized => _humanize(value);
+
+  @override
+  String toString() => value;
+
+  static bool isCamelCase(String name) => _camelCaseTester.hasMatch(name);
+
+  static String _humanize(String camelCase) =>
+      _camelCaseMatcher.allMatches(camelCase).map((m) => m.group(0)).join(' ');
+}
+
+/// Dart source linter.
+class DartLinter implements AnalysisErrorListener {
+  final errors = <AnalysisError>[];
+
+  final LinterOptions options;
+  final Reporter reporter;
+
+  /// The total number of sources that were analyzed.  Only valid after
+  /// [lintFiles] has been called.
+  int numSourcesAnalyzed;
+
+  /// Creates a new linter.
+  DartLinter(this.options, {this.reporter: const PrintingReporter()});
+
+  Iterable<AnalysisErrorInfo> lintFiles(List<File> files) {
+    List<AnalysisErrorInfo> errors = [];
+    var analysisDriver = new AnalysisDriver(options);
+    errors.addAll(analysisDriver.analyze(files.where((f) => isDartFile(f))));
+    numSourcesAnalyzed = analysisDriver.numSourcesAnalyzed;
+    files.where((f) => isPubspecFile(f)).forEach((p) {
+      numSourcesAnalyzed++;
+      return errors.addAll(_lintPubspecFile(p));
+    });
+    return errors;
+  }
+
+  Iterable<AnalysisErrorInfo> lintPubspecSource(
+      {String contents, String sourcePath}) {
+    var results = <AnalysisErrorInfo>[];
+
+    Uri sourceUrl = sourcePath == null ? null : p.toUri(sourcePath);
+
+    var spec = new Pubspec.parse(contents, sourceUrl: sourceUrl);
+
+    for (Linter lint in options.enabledLints) {
+      if (lint is LintRule) {
+        LintRule rule = lint;
+        var visitor = rule.getPubspecVisitor();
+        if (visitor != null) {
+          // Analyzer sets reporters; if this file is not being analyzed,
+          // we need to set one ourselves.  (Needless to say, when pubspec
+          // processing gets pushed down, this hack can go away.)
+          if (rule.reporter == null && sourceUrl != null) {
+            var source = createSource(sourceUrl);
+            rule.reporter = new ErrorReporter(this, source);
+          }
+          try {
+            spec.accept(visitor);
+          } on Exception catch (e) {
+            reporter.exception(new LinterException(e.toString()));
+          }
+          if (rule._locationInfo != null && rule._locationInfo.isNotEmpty) {
+            results.addAll(rule._locationInfo);
+            rule._locationInfo.clear();
+          }
+        }
+      }
+    }
+
+    return results;
+  }
+
+  @override
+  onError(AnalysisError error) => errors.add(error);
+
+  Iterable<AnalysisErrorInfo> _lintPubspecFile(File sourceFile) =>
+      lintPubspecSource(
+          contents: sourceFile.readAsStringSync(), sourcePath: sourceFile.path);
+}
+
+class FileGlobFilter extends LintFilter {
+  Iterable<Glob> includes;
+  Iterable<Glob> excludes;
+
+  FileGlobFilter([Iterable<String> includeGlobs, Iterable<String> excludeGlobs])
+      : includes = includeGlobs.map((glob) => new Glob(glob)),
+        excludes = excludeGlobs.map((glob) => new Glob(glob));
+
+  @override
+  bool filter(AnalysisError lint) {
+    // TODO specify order
+    return excludes.any((glob) => glob.matches(lint.source.fullName)) &&
+        !includes.any((glob) => glob.matches(lint.source.fullName));
+  }
+}
+
+class Group implements Comparable<Group> {
+  /// Defined rule groups.
+  static const Group errors =
+      const Group._('errors', description: 'Possible coding errors.');
+  static const Group pub = const Group._('pub',
+      description: 'Pub-related rules.',
+      link: const Hyperlink('See the <strong>Pubspec Format</strong>',
+          'https://www.dartlang.org/tools/pub/pubspec.html'));
+  static const Group style = const Group._('style',
+      description:
+          'Matters of style, largely derived from the official Dart Style Guide.',
+      link: const Hyperlink('See the <strong>Style Guide</strong>',
+          'https://www.dartlang.org/articles/style-guide/'));
+
+  /// List of builtin groups in presentation order.
+  static const Iterable<Group> builtin = const [errors, style, pub];
+
+  final String name;
+  final bool custom;
+  final String description;
+  final Hyperlink link;
+
+  factory Group(String name, {String description: '', Hyperlink link}) {
+    var n = name.toLowerCase();
+    return builtin.firstWhere((g) => g.name == n,
+        orElse: () => new Group._(name,
+            custom: true, description: description, link: link));
+  }
+
+  const Group._(this.name, {this.custom: false, this.description, this.link});
+
+  @override
+  int compareTo(Group other) => name.compareTo(other.name);
+}
+
+class Hyperlink {
+  final String label;
+  final String href;
+  final bool bold;
+  const Hyperlink(this.label, this.href, {this.bold: false});
+  String get html => '<a href="$href">${_emph(label)}</a>';
+  String _emph(msg) => bold ? '<strong>$msg</strong>' : msg;
+}
+
+/// Thrown when an error occurs in linting.
+class LinterException implements Exception {
+  /// A message describing the error.
+  final String message;
+
+  /// Creates a new LinterException with an optional error [message].
+  const LinterException([this.message]);
+
+  @override
+  String toString() =>
+      message == null ? "LinterException" : "LinterException: $message";
+}
+
+/// Linter options.
+class LinterOptions extends DriverOptions {
+  Iterable<LintRule> enabledLints;
+  LintFilter filter;
+  LinterOptions([this.enabledLints]) {
+    enabledLints ??= Registry.ruleRegistry;
+  }
+  void configure(LintConfig config) {
+    // TODO(pquitslund): revisit these default-to-on semantics.
+    enabledLints = Registry.ruleRegistry.where((LintRule rule) =>
+        !config.ruleConfigs.any((rc) => rc.disables(rule.name)));
+    filter = new FileGlobFilter(config.fileIncludes, config.fileExcludes);
+  }
+}
+
+/// Filtered lints are ommitted from linter output.
+abstract class LintFilter {
+  bool filter(AnalysisError lint);
+}
+
+/// Describes a lint rule.
+abstract class LintRule extends Linter implements Comparable<LintRule> {
+  /// Description (in markdown format) suitable for display in a detailed lint
+  /// description.
+  final String details;
+
+  /// Short description suitable for display in console output.
+  final String description;
+
+  /// Lint group (for example, 'style').
+  final Group group;
+
+  /// Lint maturity (stable|experimental).
+  final Maturity maturity;
+
+  /// Lint name.
+  @override
+  final String name;
+
+  /// Until pubspec analysis is pushed into the analyzer proper, we need to
+  /// do some extra book-keeping to keep track of details that will help us
+  /// constitute AnalysisErrorInfos.
+  final List<AnalysisErrorInfo> _locationInfo = <AnalysisErrorInfo>[];
+
+  LintRule(
+      {this.name,
+      this.group,
+      this.description,
+      this.details,
+      this.maturity: Maturity.stable});
+
+  LintCode get lintCode => new _LintCode(name, description);
+
+  @override
+  int compareTo(LintRule other) {
+    var g = group.compareTo(other.group);
+    if (g != 0) {
+      return g;
+    }
+    return name.compareTo(other.name);
+  }
+
+  /// Return a visitor to be passed to provide access to Dart project context
+  /// and to perform project-level analyses.
+  ProjectVisitor getProjectVisitor() => null;
+
+  /// Return a visitor to be passed to pubspecs to perform lint
+  /// analysis.
+  /// Lint errors are reported via this [Linter]'s error [reporter].
+  PubspecVisitor getPubspecVisitor() => null;
+
+  @override
+  AstVisitor getVisitor() => null;
+
+  void reportLint(AstNode node, {bool ignoreSyntheticNodes: true}) {
+    if (node != null && (!node.isSynthetic || !ignoreSyntheticNodes)) {
+      reporter.reportErrorForNode(lintCode, node, []);
+    }
+  }
+
+  void reportLintForToken(Token token, {bool ignoreSyntheticTokens: true}) {
+    if (token != null && (!token.isSynthetic || !ignoreSyntheticTokens)) {
+      reporter.reportErrorForToken(lintCode, token, []);
+    }
+  }
+
+  void reportPubLint(PSNode node) {
+    Source source = createSource(node.span.sourceUrl);
+
+    // Cache error and location info for creating AnalysisErrorInfos
+    // Note that error columns are 1-based
+    AnalysisError error = new AnalysisError(
+        source, node.span.start.column + 1, node.span.length, lintCode);
+    LineInfo lineInfo = new LineInfo.fromContent(source.contents.data);
+
+    _locationInfo.add(new AnalysisErrorInfoImpl([error], lineInfo));
+
+    // Then do the reporting
+    reporter?.reportError(error);
+  }
+}
+
+class Maturity implements Comparable<Maturity> {
+  static const Maturity stable = const Maturity._('stable', ordinal: 0);
+  static const Maturity experimental = const Maturity._('stable', ordinal: 1);
+
+  final String name;
+  final int ordinal;
+
+  factory Maturity(String name, {int ordinal}) {
+    switch (name.toLowerCase()) {
+      case 'stable':
+        return stable;
+      case 'experimental':
+        return experimental;
+      default:
+        return new Maturity._(name, ordinal: ordinal);
+    }
+  }
+
+  const Maturity._(this.name, {this.ordinal});
+
+  @override
+  int compareTo(Maturity other) => this.ordinal - other.ordinal;
+}
+
+class PrintingReporter implements Reporter, Logger {
+  final Printer _print;
+
+  const PrintingReporter([this._print = print]);
+
+  @override
+  void exception(LinterException exception) {
+    _print('EXCEPTION: $exception');
+  }
+
+  @override
+  void logError(String message, [CaughtException exception]) {
+    _print('ERROR: $message');
+  }
+
+  @override
+  void logInformation(String message, [CaughtException exception]) {
+    _print('INFO: $message');
+  }
+
+  @override
+  void warn(String message) {
+    _print('WARN: $message');
+  }
+}
+
+abstract class Reporter {
+  void exception(LinterException exception);
+  void warn(String message);
+}
+
+/// Linter implementation.
+class SourceLinter implements DartLinter, AnalysisErrorListener {
+  @override
+  final errors = <AnalysisError>[];
+  @override
+  final LinterOptions options;
+  @override
+  final Reporter reporter;
+
+  @override
+  int numSourcesAnalyzed;
+
+  SourceLinter(this.options, {this.reporter: const PrintingReporter()});
+
+  @override
+  Iterable<AnalysisErrorInfo> lintFiles(List<File> files) {
+    List<AnalysisErrorInfo> errors = [];
+    var analysisDriver = new AnalysisDriver(options);
+    errors.addAll(analysisDriver.analyze(files.where((f) => isDartFile(f))));
+    numSourcesAnalyzed = analysisDriver.numSourcesAnalyzed;
+    files.where((f) => isPubspecFile(f)).forEach((p) {
+      numSourcesAnalyzed++;
+      return errors.addAll(_lintPubspecFile(p));
+    });
+    return errors;
+  }
+
+  @override
+  Iterable<AnalysisErrorInfo> lintPubspecSource(
+      {String contents, String sourcePath}) {
+    var results = <AnalysisErrorInfo>[];
+
+    Uri sourceUrl = sourcePath == null ? null : p.toUri(sourcePath);
+
+    var spec = new Pubspec.parse(contents, sourceUrl: sourceUrl);
+
+    for (Linter lint in options.enabledLints) {
+      if (lint is LintRule) {
+        LintRule rule = lint;
+        var visitor = rule.getPubspecVisitor();
+        if (visitor != null) {
+          // Analyzer sets reporters; if this file is not being analyzed,
+          // we need to set one ourselves.  (Needless to say, when pubspec
+          // processing gets pushed down, this hack can go away.)
+          if (rule.reporter == null && sourceUrl != null) {
+            var source = createSource(sourceUrl);
+            rule.reporter = new ErrorReporter(this, source);
+          }
+          try {
+            spec.accept(visitor);
+          } on Exception catch (e) {
+            reporter.exception(new LinterException(e.toString()));
+          }
+          if (rule._locationInfo != null && rule._locationInfo.isNotEmpty) {
+            results.addAll(rule._locationInfo);
+            rule._locationInfo.clear();
+          }
+        }
+      }
+    }
+
+    return results;
+  }
+
+  @override
+  onError(AnalysisError error) => errors.add(error);
+
+  @override
+  Iterable<AnalysisErrorInfo> _lintPubspecFile(File sourceFile) =>
+      lintPubspecSource(
+          contents: sourceFile.readAsStringSync(), sourcePath: sourceFile.path);
+}
+
+class _LintCode extends LintCode {
+  static final registry = <String, LintCode>{};
+
+  factory _LintCode(String name, String message) => registry.putIfAbsent(
+      name + message, () => new _LintCode._(name, message));
+
+  _LintCode._(String name, String message) : super(name, message);
+}