Enhance the change builders

pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_dart.dart

Index: pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_dart.dart
diff --git a/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_dart.dart b/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_dart.dart
index 557b1503959ddef24ec3038055191b4c538c0085..35ab956774b7cb8850d4c1ef6a180f0783916684 100644
--- a/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_dart.dart
+++ b/pkg/analysis_server/lib/src/provisional/edit/utilities/change_builder_dart.dart
@@ -8,6 +8,7 @@ import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
+import 'package:analyzer/src/generated/resolver.dart';
 
 /**
  * A [ChangeBuilder] used to build changes in Dart files.
@@ -47,7 +48,7 @@ abstract class DartEditBuilder extends EditBuilder {
    * list of [interfaces] is provided, then the class will implement those
    * interfaces. If [isAbstract] is `true`, then the class will be abstract. If
    * a [memberWriter] is provided, then it will be invoked to allow members to
-   * be generated. (The members will automatically be preceeded and followed by
+   * be generated. (The members will automatically be preceded and followed by
    * end-of-line markers.) If a list of [mixins] is provided, then the class
    * will mix in those classes. If a [nameGroupName] is provided, then the name
    * of the class will be included in the linked edit group with that name. If a
@@ -61,18 +62,19 @@ abstract class DartEditBuilder extends EditBuilder {
       void memberWriter(),
       Iterable<DartType> mixins,
       String nameGroupName,
-      DartType superclass});
+      DartType superclass,
+      String superclassGroupName});
 
   /**
    * Write the code for a declaration of a field with the given [name]. If an
    * [initializerWriter] is provided, it will be invoked to write the content of
    * the initializer. (The equal sign separating the field name from the
    * initializer expression will automatically be written.) If [isConst] is
-   * `true`, then the declaration will be preceeded by the `const` keyword. If
-   * [isFinal] is `true`, then the declaration will be preceeded by the `final`
+   * `true`, then the declaration will be preceded by the `const` keyword. If
+   * [isFinal] is `true`, then the declaration will be preceded by the `final`
    * keyword. (If both [isConst] and [isFinal] are `true`, then only the `const`
    * keyword will be written.) If [isStatic] is `true`, then the declaration
-   * will be preceeded by the `static` keyword. If a [nameGroupName] is
+   * will be preceded by the `static` keyword. If a [nameGroupName] is
    * provided, the name of the field will be included in the linked edit group
    * with that name. If a [type] is provided, then it will be used as the type
    * of the field. (The keyword `var` will be provided automatically when
@@ -89,10 +91,32 @@ abstract class DartEditBuilder extends EditBuilder {
       String typeGroupName});
 
   /**
+   * Write the code for a declaration of a function with the given [name]. If a
+   * [bodyWriter] is provided, it will be invoked to write the body of the
+   * function. (The space between the name and the body will automatically be
+   * written.) If [isStatic] is `true`, then the declaration will be preceded
+   * by the `static` keyword. If a [nameGroupName] is provided, the name of the
+   * function will be included in the linked edit group with that name. If a
+   * [returnType] is provided, then it will be used as the return type of the
+   * function. If a [returnTypeGroupName] is provided, then if a return type was
+   * written it will be in the linked edit group with that name. If a
+   * [parameterWriter] is provided, then it will be invoked to write the
+   * declarations of the parameters to the function. (The parentheses around the
+   * parameters will automatically be written.)
+   */
+  void writeFunctionDeclaration(String name,
+      {void bodyWriter(),
+      bool isStatic: false,
+      String nameGroupName,
+      void parameterWriter(),
+      DartType returnType,
+      String returnTypeGroupName});
+
+  /**
    * Write the code for a declaration of a getter with the given [name]. If a
    * [bodyWriter] is provided, it will be invoked to write the body of the
    * getter. (The space between the name and the body will automatically be
-   * written.) If [isStatic] is `true`, then the declaration will be preceeded
+   * written.) If [isStatic] is `true`, then the declaration will be preceded
    * by the `static` keyword. If a [nameGroupName] is provided, the name of the
    * getter will be included in the linked edit group with that name. If a
    * [returnType] is provided, then it will be used as the return type of the
@@ -107,11 +131,44 @@ abstract class DartEditBuilder extends EditBuilder {
       String returnTypeGroupName});
 
   /**
+   * Write the code for a declaration of a local variable with the given [name].
+   * If an [initializerWriter] is provided, it will be invoked to write the
+   * content of the initializer. (The equal sign separating the variable name
+   * from the initializer expression will automatically be written.) If
+   * [isConst] is `true`, then the declaration will be preceded by the `const`
+   * keyword. If [isFinal] is `true`, then the declaration will be preceded by
+   * the `final` keyword. (If both [isConst] and [isFinal] are `true`, then only
+   * the `const` keyword will be written.) If a [nameGroupName] is provided, the
+   * name of the variable will be included in the linked edit group with that
+   * name. If a [type] is provided, then it will be used as the type of the
+   * variable. (The keyword `var` will be provided automatically when required.)
+   * If a [typeGroupName] is provided, then if a type was written it will be in
+   * the linked edit group with that name.
+   */
+  void writeLocalVariableDeclaration(String name,
+      {void initializerWriter(),
+      bool isConst: false,
+      bool isFinal: false,
+      String nameGroupName,
+      DartType type,
+      String typeGroupName});
+
+  /**
    * Append a placeholder for an override of the specified inherited [member].
    */
   void writeOverrideOfInheritedMember(ExecutableElement member);
 
   /**
+   * Write the code for a parameter that would match the given [argument]. The
+   * name of the parameter will be generated based on the type of the argument,
+   * but if the argument type is not known the [index] will be used to compose
+   * a name. In any case, the set of [usedNames] will be used to ensure that the
+   * name is unique (and the chosen name will be added to the set).
+   */
+  void writeParameterMatchingArgument(
+      Expression argument, int index, Set<String> usedNames);
+
+  /**
    * Write the code for a list of [parameters], including the surrounding
    * parentheses.
    */
@@ -119,7 +176,7 @@ abstract class DartEditBuilder extends EditBuilder {
 
   /**
    * Write the code for a list of parameters that would match the given list of
-   * [arguments], including the surrounding parentheses.
+   * [arguments]. The surrounding parentheses are *not* written.
    */
   void writeParametersMatchingArguments(ArgumentList arguments);
 
@@ -152,4 +209,41 @@ abstract class DartEditBuilder extends EditBuilder {
  *
  * Clients may not extend, implement or mix-in this class.
  */
-abstract class DartFileEditBuilder extends FileEditBuilder {}
+abstract class DartFileEditBuilder extends FileEditBuilder {
+  /**
+   * Create one or more edits that will convert the given function [body] from
+   * being synchronous to be asynchronous. This includes adding the `async`
+   * modifier to the body as well as potentially replacing the return type of
+   * the function to `Future`.
+   *
+   * There is currently a limitation in that the function body must not be a
+   * generator.
+   *
+   * Throws an [ArgumentError] if the function body is not both synchronous and
+   * a non-generator.
+   */
+  void convertFunctionFromSyncToAsync(
+      FunctionBody body, TypeProvider typeProvider);
+
+  /**
+   * Optionally create an edit to replace the given [typeAnnotation] with the
+   * type `Future` (with the given type annotation as the type argument). The
+   * [typeProvider] is used to check the current type, because if it is already
+   * `Future` no edit will be added.
+   */
+  void replaceTypeWithFuture(
+      TypeAnnotation typeAnnotation, TypeProvider typeProvider);
+}
+
+/**
+ * A [LinkedEditBuilder] used to build linked edits for Dart files.
+ *
+ * Clients may not extend, implement or mix-in this class.
+ */
+abstract class DartLinkedEditBuilder extends LinkedEditBuilder {
+  /**
+   * Add the given [type] and all of its supertypes (other than mixins) as
+   * suggestions for the current linked edit group.
+   */
+  void addSuperTypesAsSuggestions(DartType type);
+}