Fixed for latest build_test.

Author: davidmorgan

source_gen/test/external_only_type_checker_test.dart

@@ -23,22 +23,21 @@ void main() {
 
   setUpAll(() async {
     late LibraryReader thisTest;
-    await resolveSource(
-      r'''
+    await resolveSources(
+      {
+        'source_gen|test/example.dart': r'''
       export 'type_checker_test.dart' show NonPublic;
     ''',
+        'source_gen|test/type_checker_test.dart': useAssetReader,
+        'source_gen|test/external_only_type_checker_test.dart': useAssetReader,
+      },
       (resolver) async {
         thisTest = LibraryReader(
           await resolver.libraryFor(
             AssetId('source_gen', 'test/external_only_type_checker_test.dart'),
           ),
         );
       },
-      inputId: AssetId('source_gen', 'test/example.dart'),
-      nonInputsToReadFromFilesystem: {
-        AssetId('source_gen', 'test/type_checker_test.dart'),
-        AssetId('source_gen', 'test/external_only_type_checker_test.dart'),
-      },
     );
 
     staticNonPublic = thisTest

source_gen/test/type_checker_test.dart

@@ -49,11 +49,18 @@ void main() {
     late LibraryElement collection;
     late LibraryReader sourceGen;
     late LibraryElement testSource;
-    await resolveSource(
-      r'''
+    await resolveSources(
+      {
+        'source_gen|test/example.dart': r'''
       export 'package:source_gen/source_gen.dart';
       export 'type_checker_test.dart' show NonPublic;
     ''',
+        'source_gen|lib/source_gen.dart': useAssetReader,
+        'source_gen|lib/src/generator.dart': useAssetReader,
+        'source_gen|lib/src/generator_for_annotation.dart': useAssetReader,
+        'source_gen|test/type_checker_test.dart': useAssetReader,
+      },
+
       (resolver) async {
         core = (await resolver.findLibraryByName('dart.core'))!;
         collection = (await resolver.findLibraryByName('dart.collection'))!;
@@ -66,13 +73,6 @@ void main() {
           AssetId('source_gen', 'test/type_checker_test.dart'),
         );
       },
-      inputId: AssetId('source_gen', 'test/example.dart'),
-      nonInputsToReadFromFilesystem: {
-        AssetId('source_gen', 'lib/source_gen.dart'),
-        AssetId('source_gen', 'lib/src/generator.dart'),
-        AssetId('source_gen', 'lib/src/generator_for_annotation.dart'),
-        AssetId('source_gen', 'test/type_checker_test.dart'),
-      },
     );
 
     final staticIterable = core