DAS: Un-cache the assist lint rule map when registering new generators

This fixes running
`dart --enable-asserts pkg/analysis_server/test/test_all.dart`.

Change-Id: I50aef9e2d2f073ac8917b3f97dcfc0cddc0290c3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/415720
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Samuel Rawlins <[email protected]>

Author: srawlins

pkg/analysis_server/lib/src/services/correction/assist_generators.dart

@@ -19,22 +19,29 @@ class _RegisteredAssistGenerators {
   /// assists.
   final Set<MultiProducerGenerator> multiProducerGenerators = {};
 
+  Map<ProducerGenerator, Set<LintCode>>? _lintRuleMap;
+
   /// A mapping from registered _assist_ producer generators to the [LintCode]s
   /// for which they may also act as a _fix_ producer generator.
-  late Map<ProducerGenerator, Set<LintCode>> lintRuleMap = {
-    for (var generator in producerGenerators)
-      generator: {
-        for (var MapEntry(key: lintName, value: generators)
-            in registeredFixGenerators.lintProducers.entries)
-          if (generators.contains(generator)) lintName,
-      },
-  };
+  Map<ProducerGenerator, Set<LintCode>> get lintRuleMap =>
+      _lintRuleMap ??= {
+        for (var generator in producerGenerators)
+          generator: {
+            for (var MapEntry(key: lintName, value: generators)
+                in registeredFixGenerators.lintProducers.entries)
+              if (generators.contains(generator)) lintName,
+          },
+      };
 
   void registerGenerator(ProducerGenerator generator) {
     producerGenerators.add(generator);
+    // Reset the lint rule map, to account for the new generator.
+    _lintRuleMap = null;
   }
 
   void registerMultiGenerator(MultiProducerGenerator generator) {
     multiProducerGenerators.add(generator);
+    // Reset the lint rule map, to account for the new generator.
+    _lintRuleMap = null;
   }
 }

pkg/analysis_server/lib/src/services/correction/assist_internal.dart

@@ -179,9 +179,9 @@ void registerBuiltInAssistGenerators() {
   // This function can be called many times during test runs so these statements
   // should not result in duplicate producers (i.e. they should only add to maps
   // or sets or otherwise ensure producers that already exist are not added).
-  registeredAssistGenerators.producerGenerators.addAll(_builtInGenerators);
-  registeredAssistGenerators.multiProducerGenerators.addAll(
-    _builtInMultiGenerators,
+  _builtInGenerators.forEach(registeredAssistGenerators.registerGenerator);
+  _builtInMultiGenerators.forEach(
+    registeredAssistGenerators.registerMultiGenerator,
   );
 }