support analysis options include declaration

pkg/analyzer/lib/source/analysis_options_provider.dart

 // 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.
 
 library analyzer.source.analysis_options_provider;
 
 import 'dart:core';
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/source/source_resource.dart';
 import 'package:analyzer/src/util/yaml.dart';
 import 'package:source_span/source_span.dart';
 import 'package:yaml/yaml.dart';
 
 /// Provide the options found in the analysis options file.
 class AnalysisOptionsProvider {
+  /// The source factory used to resolve include declarations
+  /// in analysis options files or `null` if include is not supported.
+  SourceFactory sourceFactory;
+
+  AnalysisOptionsProvider([this.sourceFactory]);
+
   /// Provide the options found in either
   /// [root]/[AnalysisEngine.ANALYSIS_OPTIONS_FILE] or
   /// [root]/[AnalysisEngine.ANALYSIS_OPTIONS_YAML_FILE].
   /// Return an empty options map if the file does not exist.
   Map<String, YamlNode> getOptions(Folder root, {bool crawlUp: false}) {
     Resource resource;
     for (Folder folder = root; folder != null; folder = folder.parent) {
       resource = folder.getChild(AnalysisEngine.ANALYSIS_OPTIONS_FILE);
       if (resource.exists) {
         break;
       }
       resource = folder.getChild(AnalysisEngine.ANALYSIS_OPTIONS_YAML_FILE);
       if (resource.exists || !crawlUp) {
         break;
       }
     }
-    String optionsText = _readAnalysisOptionsFile(resource);
-    return getOptionsFromString(optionsText);
+    return getOptionsFromFile(resource);
   }
 
   /// Provide the options found in [file].
   /// Return an empty options map if the file does not exist.
   Map<String, YamlNode> getOptionsFromFile(File file) {
-    var optionsSource = _readAnalysisOptionsFile(file);
-    return getOptionsFromString(optionsSource);
+    return getOptionsFromSource(new FileSource(file));
+  }
+
+  /// Provide the options found in [source].
+  /// Return an empty options map if the file does not exist.
+  Map<String, YamlNode> getOptionsFromSource(Source source) {
+    Map<String, YamlNode> options =
+        getOptionsFromString(_readAnalysisOptions(source));
+    YamlNode node = options.remove('include');

[Brian Wilkerson, 2016/11/11 19:37:47]

Given that "participants" are able to look at the options in order to do their
own processing, it isn't clear to me that we should be removing the includes
key. Not sure it matters in practice, though.

[danrubel, 2016/11/14 20:39:33]

I don't think the "include" directive makes sense as part of the options once
options are merged. We can always add something like a
"getPreMergeOptionsFromSource" method if needed which will not merge and will
not remove any include directive.

That said, I can keep the "include" directive in the resulting yaml map if you'd
prefer.

+    if (sourceFactory != null && node is YamlScalar) {
+      var path = node.value;
+      if (path is String) {
+        Source parent = sourceFactory.resolveUri(source, path);
+        options = merge(getOptionsFromSource(parent), options);
+      }
+    }
+    return options;
   }
 
   /// Provide the options found in [optionsSource].
   /// Return an empty options map if the source is null.
   Map<String, YamlNode> getOptionsFromString(String optionsSource) {
     Map<String, YamlNode> options = <String, YamlNode>{};
     if (optionsSource == null) {
       return options;
     }
 
@@ skipping 51 matching lines @@
   ///   * lists of scalar values can be promoted to simple maps when merged with
   ///     maps of strings to booleans (e.g., ['opt1', 'opt2'] becomes
   ///     {'opt1': true, 'opt2': true}.
   ///   * maps are merged recursively.
   ///   * if map values cannot be merged, the overriding value is taken.
   ///
   Map<String, YamlNode> merge(
           Map<String, YamlNode> defaults, Map<String, YamlNode> overrides) =>
       new Merger().merge(defaults, overrides) as Map<String, YamlNode>;
 
-  /// Read the contents of [file] as a string.
-  /// Returns null if file does not exist.
-  String _readAnalysisOptionsFile(File file) {
+  /// Read the contents of [source] as a string.
+  /// Returns null if source is null or does not exist.
+  String _readAnalysisOptions(Source source) {
     try {
-      return file.readAsStringSync();
-    } on FileSystemException {
-      // File can't be read.
+      return source.contents.data;
+    } catch (e) {
+      // Source can't be read.
       return null;

[Brian Wilkerson, 2016/11/11 19:37:47]

There is linter support for linting options files. We should add a github issue
to add a lint for the cases where the include contains an invalid uri.

[danrubel, 2016/11/14 20:39:33]

Good idea. https://github.com/dart-lang/sdk/issues/27817

     }
   }
 }
 
 /// Thrown on options format exceptions.
 class OptionsFormatException implements Exception {
   final String message;
   final SourceSpan span;
   OptionsFormatException(this.message, [this.span]);
 
   @override
   String toString() =>
       'OptionsFormatException: ${message?.toString()}, ${span?.toString()}';
 }