Consolidate the yaml extensions in one library

Change-Id: Ide0e02145581c1a77c4af2764821c63a333d9dd1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/174520
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

Author: bwilkerson

pkg/analysis_server/lib/src/services/completion/yaml/yaml_completion_generator.dart

@@ -4,6 +4,7 @@
 
 import 'package:analysis_server/src/protocol_server.dart';
 import 'package:analysis_server/src/services/completion/yaml/producer.dart';
+import 'package:analysis_server/src/utilities/extensions/yaml.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:yaml/yaml.dart';
 
@@ -182,62 +183,3 @@ class YamlCompletionResults {
         replacementOffset = 0,
         replacementLength = 0;
 }
-
-extension on YamlMap {
-  /// Return the node representing the key that corresponds to the value
-  /// represented by the [value] node.
-  YamlNode keyAtValue(YamlNode value) {
-    for (var entry in nodes.entries) {
-      if (entry.value == value) {
-        return entry.key;
-      }
-    }
-    return null;
-  }
-}
-
-extension on YamlNode {
-  /// Return the child of this node that contains the given [offset], or `null`
-  /// if none of the children contains the offset.
-  YamlNode childContainingOffset(int offset) {
-    var node = this;
-    if (node is YamlList) {
-      for (var element in node.nodes) {
-        if (element.containsOffset(offset)) {
-          return element;
-        }
-      }
-      for (var element in node.nodes) {
-        if (element is YamlScalar && element.value == null) {
-          // TODO(brianwilkerson) Testing for a null value probably gets
-          //  confused when there are multiple null values.
-          return element;
-        }
-      }
-    } else if (node is YamlMap) {
-      for (var entry in node.nodes.entries) {
-        if ((entry.key as YamlNode).containsOffset(offset)) {
-          return entry.key;
-        }
-        var value = entry.value;
-        if (value.containsOffset(offset) ||
-            (value is YamlScalar && value.value == null)) {
-          // TODO(brianwilkerson) Testing for a null value probably gets
-          //  confused when there are multiple null values or when there is a
-          //  null value before the node that actually contains the offset.
-          return entry.value;
-        }
-      }
-    }
-    return null;
-  }
-
-  /// Return `true` if this node contains the given [offset].
-  bool containsOffset(int offset) {
-    // TODO(brianwilkerson) Nodes at the end of the file contain any trailing
-    //  whitespace. This needs to be accounted for, here or elsewhere.
-    var nodeOffset = span.start.offset;
-    var nodeEnd = nodeOffset + span.length;
-    return nodeOffset <= offset && offset <= nodeEnd;
-  }
-}

pkg/analysis_server/lib/src/services/correction/fix/data_driven/transform_set_parser.dart

@@ -1033,18 +1033,3 @@ class TransformSetParser {
     }
   }
 }
-
-extension on YamlMap {
-  // TODO(brianwilkerson) Copied from YamlCompletionGenerator. Refactor to a
-  //  utility file that is shared between them.
-  /// Return the node representing the key that corresponds to the value
-  /// represented by the [value] node.
-  YamlNode keyAtValue(YamlNode value) {
-    for (var entry in nodes.entries) {
-      if (entry.value == value) {
-        return entry.key;
-      }
-    }
-    return null;
-  }
-}

pkg/analysis_server/lib/src/utilities/extensions/yaml.dart

@@ -5,6 +5,17 @@
 import 'package:yaml/yaml.dart';
 
 extension YamlMapExtensions on YamlMap {
+  /// Return the node representing the key that corresponds to the value
+  /// represented by the [value] node.
+  YamlNode keyAtValue(YamlNode value) {
+    for (var entry in nodes.entries) {
+      if (entry.value == value) {
+        return entry.key;
+      }
+    }
+    return null;
+  }
+
   /// Return the value associated with the key whose value matches the given
   /// [key], or `null` if there is no matching key.
   YamlNode valueAt(String key) {
@@ -16,3 +27,49 @@ extension YamlMapExtensions on YamlMap {
     return null;
   }
 }
+
+extension YamlNodeExtensions on YamlNode {
+  /// Return the child of this node that contains the given [offset], or `null`
+  /// if none of the children contains the offset.
+  YamlNode childContainingOffset(int offset) {
+    var node = this;
+    if (node is YamlList) {
+      for (var element in node.nodes) {
+        if (element.containsOffset(offset)) {
+          return element;
+        }
+      }
+      for (var element in node.nodes) {
+        if (element is YamlScalar && element.value == null) {
+          // TODO(brianwilkerson) Testing for a null value probably gets
+          //  confused when there are multiple null values.
+          return element;
+        }
+      }
+    } else if (node is YamlMap) {
+      for (var entry in node.nodes.entries) {
+        if ((entry.key as YamlNode).containsOffset(offset)) {
+          return entry.key;
+        }
+        var value = entry.value;
+        if (value.containsOffset(offset) ||
+            (value is YamlScalar && value.value == null)) {
+          // TODO(brianwilkerson) Testing for a null value probably gets
+          //  confused when there are multiple null values or when there is a
+          //  null value before the node that actually contains the offset.
+          return entry.value;
+        }
+      }
+    }
+    return null;
+  }
+
+  /// Return `true` if this node contains the given [offset].
+  bool containsOffset(int offset) {
+    // TODO(brianwilkerson) Nodes at the end of the file contain any trailing
+    //  whitespace. This needs to be accounted for, here or elsewhere.
+    var nodeOffset = span.start.offset;
+    var nodeEnd = nodeOffset + span.length;
+    return nodeOffset <= offset && offset <= nodeEnd;
+  }
+}