Switch analysis_server to 2.15

So, we can use constructor tear-offs :-)

Change-Id: Ib819da7715e49496b01defa9dc3837bd70019134
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/240642
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

.dart_tool/package_config.json

@@ -69,7 +69,7 @@
       "name": "analysis_server",
       "rootUri": "../pkg/analysis_server",
       "packageUri": "lib/",
-      "languageVersion": "2.14"
+      "languageVersion": "2.15"
     },
     {
       "name": "analysis_server_client",

pkg/analysis_server/lib/src/analysis_server.dart

@@ -85,33 +85,21 @@ class AnalysisServer extends AbstractAnalysisServer {
   /// A map from the name of a request to a function used to create a request
   /// handler.
   static final Map<String, HandlerGenerator> handlerGenerators = {
-    ANALYTICS_REQUEST_IS_ENABLED: (server, request, cancellationToken) =>
-        AnalyticsIsEnabledHandler(server, request, cancellationToken),
-    ANALYTICS_REQUEST_ENABLE: (server, request, cancellationToken) =>
-        AnalyticsEnableHandler(server, request, cancellationToken),
-    ANALYTICS_REQUEST_SEND_EVENT: (server, request, cancellationToken) =>
-        AnalyticsSendEventHandler(server, request, cancellationToken),
-    ANALYTICS_REQUEST_SEND_TIMING: (server, request, cancellationToken) =>
-        AnalyticsSendTimingHandler(server, request, cancellationToken),
+    ANALYTICS_REQUEST_IS_ENABLED: AnalyticsIsEnabledHandler.new,
+    ANALYTICS_REQUEST_ENABLE: AnalyticsEnableHandler.new,
+    ANALYTICS_REQUEST_SEND_EVENT: AnalyticsSendEventHandler.new,
+    ANALYTICS_REQUEST_SEND_TIMING: AnalyticsSendTimingHandler.new,
     //
-    DIAGNOSTIC_REQUEST_GET_DIAGNOSTICS: (server, request, cancellationToken) =>
-        DiagnosticGetDiagnosticsHandler(server, request, cancellationToken),
-    DIAGNOSTIC_REQUEST_GET_SERVER_PORT: (server, request, cancellationToken) =>
-        DiagnosticGetServerPortHandler(server, request, cancellationToken),
+    DIAGNOSTIC_REQUEST_GET_DIAGNOSTICS: DiagnosticGetDiagnosticsHandler.new,
+    DIAGNOSTIC_REQUEST_GET_SERVER_PORT: DiagnosticGetServerPortHandler.new,
     //
-    EXECUTION_REQUEST_CREATE_CONTEXT: (server, request, cancellationToken) =>
-        ExecutionCreateContextHandler(server, request, cancellationToken),
-    EXECUTION_REQUEST_DELETE_CONTEXT: (server, request, cancellationToken) =>
-        ExecutionDeleteContextHandler(server, request, cancellationToken),
-    EXECUTION_REQUEST_GET_SUGGESTIONS: (server, request, cancellationToken) =>
-        ExecutionGetSuggestionsHandler(server, request, cancellationToken),
-    EXECUTION_REQUEST_MAP_URI: (server, request, cancellationToken) =>
-        ExecutionMapUriHandler(server, request, cancellationToken),
-    EXECUTION_REQUEST_SET_SUBSCRIPTIONS: (server, request, cancellationToken) =>
-        ExecutionSetSubscriptionsHandler(server, request, cancellationToken),
+    EXECUTION_REQUEST_CREATE_CONTEXT: ExecutionCreateContextHandler.new,
+    EXECUTION_REQUEST_DELETE_CONTEXT: ExecutionDeleteContextHandler.new,
+    EXECUTION_REQUEST_GET_SUGGESTIONS: ExecutionGetSuggestionsHandler.new,
+    EXECUTION_REQUEST_MAP_URI: ExecutionMapUriHandler.new,
+    EXECUTION_REQUEST_SET_SUBSCRIPTIONS: ExecutionSetSubscriptionsHandler.new,
     //
-    KYTHE_REQUEST_GET_KYTHE_ENTRIES: (server, request, cancellationToken) =>
-        KytheGetKytheEntriesHandler(server, request, cancellationToken),
+    KYTHE_REQUEST_GET_KYTHE_ENTRIES: KytheGetKytheEntriesHandler.new,
   };
 
   /// The channel from which requests are received and to which responses should

pkg/analysis_server/pubspec.yaml

@@ -3,7 +3,7 @@ name: analysis_server
 publish_to: none
 
 environment:
-  sdk: '>=2.14.0 <3.0.0'
+  sdk: '>=2.15.0 <3.0.0'
 
 dependencies:
   _fe_analyzer_shared:

pkg/analysis_server/test/integration/lsp_server/integration_tests.dart

@@ -150,7 +150,8 @@ class LspServerClient {
 
     var dartBinary = join(dartSdkPath, 'bin', 'dart');
 
-    var useSnapshot = true;
+    // Prevent flow analysis from marking code below as being dead.
+    const useSnapshot = 1 > 0;
     String serverPath;
 
     if (useSnapshot) {

pkg/analysis_server/test/integration/support/integration_tests.dart

@@ -622,9 +622,8 @@ class Server {
 
     var dartBinary = path.join(dartSdkPath, 'bin', 'dart');
 
-    // The integration tests run 3x faster when run from snapshots (you need to
-    // run test.py with --use-sdk).
-    var useSnapshot = true;
+    // Prevent flow analysis from marking code below as being dead.
+    const useSnapshot = 1 > 0;
     String serverPath;
 
     if (useSnapshot) {