[analyzer]/[analysis_server] Handle parse errors in analysis_options.yaml better + tweak unhandled exception text

Fixes the main issues at https://github.com/dart-lang/sdk/issues/55987

Change-Id: I5b86f7c0df4017c02b96e67d8d8d03b71933b318
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/371861
Reviewed-by: Sam Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/test/lsp/diagnostic_test.dart

@@ -135,6 +135,26 @@ include: package:pedantic/analysis_options.yaml
     // expect(updatedDiagnostics, hasLength(0));
   }
 
+  /// Ensure the server can initialize correctly and send diagnostics when the
+  /// analysis_options file throws errors during parsing.
+  ///
+  /// https://github.com/dart-lang/sdk/issues/55987
+  Future<void> test_analysisOptionsFile_parseError() async {
+    newFile(analysisOptionsPath, '''
+include: package:lints/recommended.yaml
+f
+
+''');
+
+    var firstDiagnosticsUpdate = waitForDiagnostics(analysisOptionsUri);
+    await initialize();
+    var initialDiagnostics = await firstDiagnosticsUpdate;
+    var diagnostic = initialDiagnostics!.first;
+    expect(diagnostic.severity, DiagnosticSeverity.Error);
+    expect(diagnostic.code, 'parse_error');
+    expect(diagnostic.message, "Expected ':'.");
+  }
+
   Future<void> test_contextMessage() async {
     newFile(mainFilePath, '''
 void f() {

pkg/analyzer/lib/src/analysis_options/analysis_options_provider.dart

@@ -24,7 +24,8 @@ class AnalysisOptionsProvider {
   /// [root]/[file_paths.analysisOptionsYaml].
   /// Recursively merge options referenced by an include directive
   /// and remove the include directive from the resulting options map.
-  /// Return an empty options map if the file does not exist.
+  /// Return an empty options map if the file does not exist or cannot be
+  /// parsed.
   YamlMap getOptions(Folder root) {
     File? optionsFile = getOptionsFile(root);
     if (optionsFile == null) {
@@ -51,7 +52,8 @@ class AnalysisOptionsProvider {
   /// Provide the options found in [file].
   /// Recursively merge options referenced by an include directive
   /// and remove the include directive from the resulting options map.
-  /// Return an empty options map if the file does not exist.
+  /// Return an empty options map if the file does not exist or cannot be
+  /// parsed.
   YamlMap getOptionsFromFile(File file) {
     return getOptionsFromSource(FileSource(file));
   }
@@ -60,21 +62,25 @@ class AnalysisOptionsProvider {
   ///
   /// Recursively merge options referenced by an `include` directive and remove
   /// the `include` directive from the resulting options map. Return an empty
-  /// options map if the file does not exist.
+  /// options map if the file does not exist or cannot be parsed.
   YamlMap getOptionsFromSource(Source source) {
-    YamlMap options = getOptionsFromString(_readAnalysisOptions(source));
+    try {
-    var node = options.valueAt(AnalyzerOptions.include);
+      YamlMap options = getOptionsFromString(_readAnalysisOptions(source));
-    var sourceFactory = this.sourceFactory;
+      var node = options.valueAt(AnalyzerOptions.include);
-    if (sourceFactory != null && node is YamlScalar) {
+      var sourceFactory = this.sourceFactory;
-      var path = node.value;
+      if (sourceFactory != null && node is YamlScalar) {
-      if (path is String) {
+        var path = node.value;
-        var parent = sourceFactory.resolveUri(source, path);
+        if (path is String) {
-        if (parent != null) {
+          var parent = sourceFactory.resolveUri(source, path);
-          options = merge(getOptionsFromSource(parent), options);
+          if (parent != null) {
+            options = merge(getOptionsFromSource(parent), options);
+          }
         }
       }
+      return options;
+    } on OptionsFormatException {
+      return YamlMap();
     }
-    return options;
   }
 
   /// Provide the options found in [content].

pkg/dartdev/lib/src/analysis_server.dart

@@ -295,8 +295,12 @@ class AnalysisServer {
   void _handleServerError(Map<String, dynamic>? error) {
     _serverErrorReceived = true;
     final err = error!;
+    log.stderr('An unexpected error was encountered by the Analysis Server.');
+    log.stderr('Please file an issue at '
+        'https://github.com/dart-lang/sdk/issues/new/choose with the following '
+        'details:\n');
     // Fields are 'isFatal', 'message', and 'stackTrace'.
-    log.stderr('Error from the analysis server: ${err['message']}');
+    log.stderr(err['message']);
     if (err['stackTrace'] != null) {
       log.stderr(err['stackTrace'] as String);
     }