[analysis_server] Return EditableArguments in parameter order

Originally we put those with arguments first so that in the property editor they'd be at the top. However the results in the order changing if you add/remove them, and across widget instances.

Returning them in source order keeps the consistent (and allows the "more important" ones to be at the top), though nothing prevents having a different sort (or an option to change it) on the client side.

Change-Id: I4808f0cb2ae5fcbb6d5496aa736528e60ac7c935
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/403582
Reviewed-by: Elliott Brooks <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: DanTup

pkg/analysis_server/lib/src/lsp/handlers/custom/editable_arguments/handler_editable_arguments.dart

@@ -104,23 +104,20 @@ class EditableArgumentsHandler
     ) = invocation;
 
     // Build the complete list of editable arguments.
+    //
+    // Arguments should be returned in the order of the parameters in the source
+    // code. This keeps things consistent across different instances of the same
+    // Widget class and prevents the order from changing as a user adds/removes
+    // arguments.
+    //
+    // If an editor wants to sort provided arguments first (and keep these stable
+    // across add/removes) it could still do so client-side, whereas if server
+    // orders them that way, the opposite (using source-order) is not possible.
     var editableArguments = [
-      // First arguments that exist in the order they were specified.
-      for (var MapEntry(key: parameter, value: argument)
-          in parameterArguments.entries)
+      for (var parameter in parameters)
         _toEditableArgument(
           parameter,
-          argument,
-          numPositionals: numPositionals,
-          numSuppliedPositionals: numSuppliedPositionals,
-        ),
-      // Then the remaining parameters that don't have existing arguments.
-      for (var parameter in parameters.where(
-        (p) => !parameterArguments.containsKey(p),
-      ))
-        _toEditableArgument(
-          parameter,
-          null,
+          parameterArguments[parameter],
           positionalIndex: positionalParameterIndexes[parameter],
           numPositionals: numPositionals,
           numSuppliedPositionals: numSuppliedPositionals,

pkg/analysis_server/test/lsp/editable_arguments_test.dart

@@ -137,10 +137,10 @@ class MyWidget extends StatelessWidget {
     expect(
       result,
       hasArgs(
-        orderedEquals([
+        unorderedEquals([
           isArg('aPositionalSupplied', hasArgument: true),
-          isArg('aNamedSupplied', hasArgument: true),
           isArg('aPositionalNotSupplied', hasArgument: false),
+          isArg('aNamedSupplied', hasArgument: true),
           isArg('aNamedNotSupplied', hasArgument: false),
         ]),
       ),
@@ -727,8 +727,14 @@ class MyWidget extends StatelessWidget {
     expect(result, hasArgNamed('a1'));
   }
 
-  /// Arguments should be returned in the order at the call site followed by
-  /// by the unspecified parameters.
+  /// Arguments should be returned in the order of the parameters in the source
+  /// code. This keeps things consistent across different instances of the same
+  /// Widget class and prevents the order from changing as a user adds/removes
+  /// arguments.
+  ///
+  /// If an editor wants to sort provided arguments first (and keep these stable
+  /// across add/removes) it could still do so client-side, whereas if server
+  /// orders them that way, the opposite (using source-order) is not possible.
   test_order() async {
     var result = await getEditableArgumentsFor('''
 class MyWidget extends StatelessWidget {
@@ -749,11 +755,11 @@ class MyWidget extends StatelessWidget {
       result,
       hasArgs(
         orderedEquals([
-          isArg('b1'),
-          isArg('a1'),
           isArg('c1'),
           isArg('c2'),
+          isArg('a1'),
           isArg('a2'),
+          isArg('b1'),
           isArg('b2'),
         ]),
       ),