Ensure we have a matcher score for every suggestion

Change-Id: I1b2ae695deeaec05d11ca40d1367883667e4fee0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/370300
Reviewed-by: Keerti Parthasarathy <keertip@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/services/completion/dart/declaration_helper.dart

@@ -209,7 +209,7 @@ class DeclarationHelper {
 
       if (importElement.prefix case var importPrefix?) {
         if (importPrefix is DeferredImportElementPrefix) {
-          var matcherScore = state.matcher.score(importedLibrary.displayName);
+          var matcherScore = state.matcher.score('loadLibrary');
           if (matcherScore != -1) {
             collector.addSuggestion(
               LoadLibraryFunctionSuggestion(
@@ -1604,7 +1604,10 @@ class DeclarationHelper {
 
   /// Adds a suggestion for the method `call` defined on the class `Function`.
   void _suggestFunctionCall() {
-    collector.addSuggestion(FunctionCall(matcherScore: 0));
+    var matcherScore = state.matcher.score('call');
+    if (matcherScore != -1) {
+      collector.addSuggestion(FunctionCall(matcherScore: matcherScore));
+    }
   }
 
   /// Adds a suggestion for the local function represented by the [element].

pkg/analysis_server/lib/src/services/completion/dart/override_helper.dart

@@ -2,6 +2,8 @@
 // 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 'dart:math' as math;
+
 import 'package:analysis_server/src/services/completion/dart/candidate_suggestion.dart';
 import 'package:analysis_server/src/services/completion/dart/completion_state.dart';
 import 'package:analysis_server/src/services/completion/dart/suggestion_collector.dart';
@@ -42,9 +44,10 @@ class OverrideHelper {
       // Gracefully degrade if the overridden element has not been resolved.
       if (element != null) {
         var invokeSuper = interface.isSuperImplemented(name);
-        // TODO(keertip): Use both "override" and the name of the overridden
-        //  member to compute the score.
-        var matcherScore = 0.0;
+        var matcherScore = math.max(
+            math.max(state.matcher.score('override'),
+                state.matcher.score('operator')),
+            state.matcher.score(element.displayName));
         if (matcherScore != -1) {
           collector.addSuggestion(
             OverrideSuggestion(