Don't pass null to fasta.Parser.

Fixes null safety errors arising from the migration of _fe_analyzer_shared.

Change-Id: I7da6b7f2d7c23d5d8f6ed120e03aed754aff5b82
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176061
Commit-Queue: Paul Berry <[email protected]>
Commit-Queue: Ivan Inozemtsev <[email protected]>
Auto-Submit: Paul Berry <[email protected]>
Reviewed-by: Ivan Inozemtsev <[email protected]>

Author: stereotype441

pkg/_fe_analyzer_shared/lib/src/parser/parser_impl.dart

@@ -297,7 +297,8 @@ class Parser {
     return cachedRewriter ??= new TokenStreamRewriterImpl();
   }
 
-  Parser(this.listener);
+  Parser(this.listener)
+      : assert(listener != null); // ignore:unnecessary_null_comparison
 
   bool get inGenerator {
     return asyncState == AsyncModifier.AsyncStar ||

pkg/analyzer/lib/src/generated/parser.dart

@@ -117,16 +117,15 @@ class Parser {
   Token currentToken;
 
   /// The fasta parser being wrapped.
-  final fasta.Parser fastaParser;
+  /*late final*/ fasta.Parser fastaParser;
 
   /// The builder which creates the analyzer AST data structures
   /// based on the Fasta parser.
   final AstBuilder astBuilder;
 
   Parser(Source source, AnalysisErrorListener errorListener,
       {@required FeatureSet featureSet, bool allowNativeClause = true})
-      : fastaParser = fasta.Parser(null),
-        astBuilder = AstBuilder(
+      : astBuilder = AstBuilder(
             ErrorReporter(
               errorListener,
               source,
@@ -136,7 +135,7 @@ class Parser {
             source.uri,
             true,
             featureSet) {
-    fastaParser.listener = astBuilder;
+    fastaParser = fasta.Parser(astBuilder);
     astBuilder.parser = fastaParser;
     astBuilder.allowNativeClause = allowNativeClause;
   }

pkg/analyzer/test/generated/parser_fasta_test.dart

@@ -2075,10 +2075,9 @@ class FastaParserTestCase
       source,
       isNonNullableByDefault: false,
     );
-    fasta.Parser parser = fasta.Parser(null);
     AstBuilder astBuilder =
         AstBuilder(errorReporter, source.uri, true, featureSet);
-    parser.listener = astBuilder;
+    fasta.Parser parser = fasta.Parser(astBuilder);
     astBuilder.parser = parser;
     astBuilder.allowNativeClause = allowNativeClause;
     parser.parseUnit(_fastaTokens);