Reapply "Move the linter core to the analyzer package"

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

Index: pkg/analyzer/lib/src/lint/config.dart
diff --git a/pkg/analyzer/lib/src/lint/config.dart b/pkg/analyzer/lib/src/lint/config.dart
new file mode 100644
index 0000000000000000000000000000000000000000..f33b3f3392b77e7e7cc99efc55c936e322aa360e
--- /dev/null
+++ b/pkg/analyzer/lib/src/lint/config.dart
@@ -0,0 +1,243 @@
+// 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 'package:yaml/yaml.dart';
+
+/**
+ * Parse the given map into a lint config.
+ */
+LintConfig parseConfig(Map optionsMap) {
+  if (optionsMap != null) {
+    var options = optionsMap['linter'];
+    // Quick check of basic contract.
+    if (options is Map) {
+      return new LintConfig.parseMap(options);
+    }
+  }
+  return null;
+}
+
+/**
+ * Process the given option [fileContents] and produce a corresponding
+ * [LintConfig].
+ */
+LintConfig processAnalysisOptionsFile(String fileContents, {String fileUrl}) {
+  var yaml = loadYamlNode(fileContents, sourceUrl: fileUrl);
+  if (yaml is YamlMap) {
+    return parseConfig(yaml);
+  }
+  return null;
+}
+
+/**
+ * The configuration of lint rules within an analysis options file.
+ */
+abstract class LintConfig {
+  factory LintConfig.parse(String source, {String sourceUrl}) =>
+      new _LintConfig().._parse(source, sourceUrl: sourceUrl);
+
+  factory LintConfig.parseMap(Map map) => new _LintConfig().._parseMap(map);
+
+  List<String> get fileExcludes;
+  List<String> get fileIncludes;
+  List<RuleConfig> get ruleConfigs;
+}
+
+/**
+ * The configuration of a single lint rule within an analysis options file.
+ */
+abstract class RuleConfig {
+  Map<String, dynamic> args = <String, dynamic>{};
+  String get group;
+  String get name;
+
+  // Provisional
+  bool disables(String ruleName) =>
+      ruleName == name && args['enabled'] == false;
+
+  bool enables(String ruleName) => ruleName == name && args['enabled'] == true;
+}
+
+class _LintConfig implements LintConfig {
+  @override
+  final fileIncludes = <String>[];
+  @override
+  final fileExcludes = <String>[];
+  @override
+  final ruleConfigs = <RuleConfig>[];
+
+  void addAsListOrString(value, List<String> list) {
+    if (value is List) {
+      value.forEach((v) => list.add(v));
+    } else if (value is String) {
+      list.add(value);
+    }
+  }
+
+  bool asBool(scalar) {
+    if (scalar is bool) {
+      return scalar;
+    }
+    if (scalar is String) {
+      if (scalar == 'true') {
+        return true;
+      }
+      if (scalar == 'false') {
+        return false;
+      }
+    }
+    return null;
+  }
+
+  String asString(scalar) {
+    if (scalar is String) {
+      return scalar;
+    }
+    return null;
+  }
+
+  Map<String, dynamic> parseArgs(args) {
+    bool enabled = asBool(args);
+    if (enabled != null) {
+      return {'enabled': enabled};
+    }
+    return null;
+  }
+
+  void _parse(String src, {String sourceUrl}) {
+    var yaml = loadYamlNode(src, sourceUrl: sourceUrl);
+    if (yaml is YamlMap) {
+      _parseYaml(yaml);
+    }
+  }
+
+  void _parseMap(Map options) {
+    //TODO(pq): unify map parsing.
+    if (options is YamlMap) {
+      _parseYaml(options);
+    } else {
+      _parseRawMap(options);
+    }
+  }
+
+  void _parseRawMap(Map options) {
+    options.forEach((k, v) {
+      if (k is! String) {
+        return;
+      }
+      String key = k;
+      switch (key) {
+        case 'files':
+          if (v is Map) {
+            addAsListOrString(v['include'], fileIncludes);
+            addAsListOrString(v['exclude'], fileExcludes);
+          }
+          break;
+
+        case 'rules':
+          // - unnecessary_getters
+          // - camel_case_types
+          if (v is List) {
+            v.forEach((rule) {
+              var config = new _RuleConfig();
+              config.name = asString(rule);
+              config.args = {'enabled': true};
+              ruleConfigs.add(config);
+            });
+          }
+
+          // {unnecessary_getters: false, camel_case_types: true}
+          if (v is Map) {
+            v.forEach((key, value) {
+              // style_guide: {unnecessary_getters: false, camel_case_types: true}
+              if (value is Map) {
+                value.forEach((rule, args) {
+                  // unnecessary_getters: false
+                  var config = new _RuleConfig();
+                  config.group = key;
+                  config.name = asString(rule);
+                  config.args = parseArgs(args);
+                  ruleConfigs.add(config);
+                });
+              } else {
+                //{unnecessary_getters: false}
+                value = asBool(value);
+                if (value != null) {
+                  var config = new _RuleConfig();
+                  config.name = asString(key);
+                  config.args = {'enabled': value};
+                  ruleConfigs.add(config);
+                }
+              }
+            });
+          }
+          break;
+      }
+    });
+  }
+
+  void _parseYaml(YamlMap yaml) {
+    yaml.nodes.forEach((k, v) {
+      if (k is! YamlScalar) {
+        return;
+      }
+      YamlScalar key = k;
+      switch (key.toString()) {
+        case 'files':
+          if (v is YamlMap) {
+            addAsListOrString(v['include'], fileIncludes);
+            addAsListOrString(v['exclude'], fileExcludes);
+          }
+          break;
+
+        case 'rules':
+
+          // - unnecessary_getters
+          // - camel_case_types
+          if (v is List) {
+            (v as List).forEach((rule) {
+              var config = new _RuleConfig();
+              config.name = asString(rule);
+              config.args = {'enabled': true};
+              ruleConfigs.add(config);
+            });
+          }
+
+          // style_guide: {unnecessary_getters: false, camel_case_types: true}
+          if (v is YamlMap) {
+            v.forEach((key, value) {
+              //{unnecessary_getters: false}
+              if (value is bool) {
+                var config = new _RuleConfig();
+                config.name = asString(key);
+                config.args = {'enabled': value};
+                ruleConfigs.add(config);
+              }
+
+              // style_guide: {unnecessary_getters: false, camel_case_types: true}
+              if (value is YamlMap) {
+                value.forEach((rule, args) {
+                  // TODO: verify format
+                  // unnecessary_getters: false
+                  var config = new _RuleConfig();
+                  config.group = key;
+                  config.name = asString(rule);
+                  config.args = parseArgs(args);
+                  ruleConfigs.add(config);
+                });
+              }
+            });
+          }
+          break;
+      }
+    });
+  }
+}
+
+class _RuleConfig extends RuleConfig {
+  @override
+  String group;
+  @override
+  String name;
+}