Validate part directive for libs with parts

lib/src/builder/builder.dart

@@ -121,10 +121,7 @@ class OverReactBuilder extends Builder {
     }
 
     // Collect all of the part files for this library.
-    final parts = libraryUnit.directives
-      .whereType<PartDirective>()
-      // Ignore all generated `.g.dart` parts.
-      .where((part) => !part.uri.stringValue.endsWith('.g.dart'));
+    final parts = getNonGeneratedParts(libraryUnit);
 
     // Generate over_react code for the input library.
     generateForFile(source, buildStep.inputId, libraryUnit);

lib/src/builder/util.dart

@@ -42,6 +42,12 @@ Uri idToPackageUri(AssetId id) {
       path: p.url.join(id.package, id.path.replaceFirst('lib/', '')));
 }
 
+Iterable<PartDirective> getNonGeneratedParts(CompilationUnit libraryUnit) {
+  return libraryUnit.directives
+      .whereType<PartDirective>()
+      // Ignore all generated `.g.dart` parts.
+      .where((part) => !part.uri.stringValue.endsWith('.g.dart'));
+}
 /// Returns true if the given compilation unit is a part file.
 bool isPart(CompilationUnit unit) =>
     unit.directives.any((directive) => directive is PartOfDirective);

tools/analyzer_plugin/lib/src/diagnostic/boilerplate_validator.dart

@@ -1,12 +1,16 @@
 import 'dart:async';
+import 'dart:io';
 
 import 'package:analyzer/dart/analysis/results.dart';
+import 'package:analyzer/dart/analysis/utilities.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/source/source_range.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:meta/meta.dart';
 // ignore: implementation_imports
 import 'package:over_react/src/builder/parsing.dart';
+// ignore: implementation_imports
+import 'package:over_react/src/builder/util.dart';
 import 'package:over_react_analyzer_plugin/src/diagnostic_contributor.dart';
 import 'package:over_react_analyzer_plugin/src/util/boilerplate_utils.dart';
 import 'package:source_span/source_span.dart';
@@ -31,12 +35,28 @@ class BoilerplateValidatorDiagnostic extends DiagnosticContributor {
   PartDirective _overReactGeneratedPartDirective;
   bool _overReactGeneratedPartDirectiveIsValid;
 
-  @override
-  Future<void> computeErrors(result, collector) async {
-    _overReactGeneratedPartDirective = getOverReactGeneratedPartDirective(result.unit);
-    _overReactGeneratedPartDirectiveIsValid = _overReactGeneratedPartDirective != null &&
-        overReactGeneratedPartDirectiveIsValid(_overReactGeneratedPartDirective, result.uri);
+  /// Returns true if the [unit] representing a part file has declarations.
+  ///
+  /// Does not report any errors for the part file, as those are handled when the part file is analyzed
+  bool _partHasDeclarations(CompilationUnit unit, ResolvedUnitResult parentResult) {
+     return getBoilerplateDeclarations(detectBoilerplateMembers(unit), ErrorCollector.callback(
+      SourceFile.fromString(parentResult.content, url: parentResult.path),
+      onError: (message, [span]) {
+        // no-op. It is assumed this method will run for parent files, and the part file will get analyzed in it's own
+        // context
+      },
+      onWarning: (message, [span]) {
+        // no-op. It is assumed this method will run for parent files, and the part file will get analyzed in it's own
+        // context
+      },
+    )).isNotEmpty;
+  }
 
+  /// Computes errors for over_react boilerplate
+  ///
+  /// Also returns whether the component has valid over_react declarations, which is useful in determining whether to
+  /// validate the generated part directive.
+  Future<bool> _computeBoilerPlateErrors(ResolvedUnitResult result, DiagnosticCollector collector) async {
     final debugMatch = _debugFlagPattern.firstMatch(result.content);
     final debug = debugMatch != null;
     if (debug) {
@@ -67,6 +87,8 @@ class BoilerplateValidatorDiagnostic extends DiagnosticContributor {
       // Do not lint anything that is not a likely boilerplate member that will actually get generated.
       if (member.versionConfidences.toList().every((vcp) => vcp.confidence <= Confidence.neutral)) continue;
 
+      if (isPart(result.unit)) continue;
+
       if (_overReactGeneratedPartDirective == null) {
         await _addPartDirectiveErrorForMember(
           result: result,
@@ -82,6 +104,7 @@ class BoilerplateValidatorDiagnostic extends DiagnosticContributor {
           errorType: PartDirectiveErrorType.invalid,
         );
       }
+
     }
 
     final declarations = getBoilerplateDeclarations(members, errorCollector).toList();
@@ -100,10 +123,11 @@ class BoilerplateValidatorDiagnostic extends DiagnosticContributor {
         }
       }
     }
+    return declarations.isNotEmpty;
+  }
 
-    // TODO: this logic does not handle when the component is already in a part file. We should refactor this to share logic that the builder uses to validate parts.
-    // <https://github.com/Workiva/over_react/issues/522>
-    if (declarations.isEmpty && _overReactGeneratedPartDirective != null) {
+  Future<void> _computePartDirectiveErrors(ResolvedUnitResult result, DiagnosticCollector collector, bool hasDeclarations) async {
+    if (!hasDeclarations && _overReactGeneratedPartDirective != null) {
       await collector.addErrorWithFix(
         errorCode,
         result.locationFor(_overReactGeneratedPartDirective),
@@ -118,13 +142,13 @@ class BoilerplateValidatorDiagnostic extends DiagnosticContributor {
           removeOverReactGeneratedPartDirective(builder, result.unit);
         }),
       );
-    } else if (declarations.isNotEmpty &&
+    } else if (hasDeclarations &&
         _overReactGeneratedPartDirective != null &&
         !_overReactGeneratedPartDirectiveIsValid) {
       await collector.addErrorWithFix(
         errorCode,
         result.locationFor(_overReactGeneratedPartDirective),
-        errorMessageArgs: ['The generated part name must match the name of the file that contains it.'],
+        errorMessageArgs: ['The generated part name must match the name of the file that contains it, but with `over_react.g.dart` for the file extension.'],
         fixKind: invalidGeneratedPartFixKind,
         computeFix: () => buildFileEdit(result, (builder) {
           fixOverReactGeneratedPartDirective(builder, result.unit, result.uri);
@@ -133,6 +157,43 @@ class BoilerplateValidatorDiagnostic extends DiagnosticContributor {
     }
   }
 
+  @override
+  Future<void> computeErrors(result, collector) async {
+    _overReactGeneratedPartDirective = getOverReactGeneratedPartDirective(result.unit);
+    _overReactGeneratedPartDirectiveIsValid =_overReactGeneratedPartDirective != null &&
+        overReactGeneratedPartDirectiveIsValid(_overReactGeneratedPartDirective, result.uri);
+
+    final hasDeclarations = await _computeBoilerPlateErrors(result, collector);
+    if (isPart(result.unit)) {
+      return;
+    }
+
+    final parts = getNonGeneratedParts(result.unit);
+
+    // compute errors for parts files
+    var anyPartHasDeclarations = false;
+    for (final part in parts) {
+      final uri = Uri.parse(part.uriElement.toString());
+      final fileContents = File.fromUri(uri).readAsStringSync();
+
+      final partResult = parseString(content: fileContents,
+          path: part.uriElement.toString(),
+          throwIfDiagnostics: false);
+
+      if (partResult.errors.isNotEmpty) {
+        // Error parsing file, skip.
+        continue;
+      }
+
+      if (_partHasDeclarations(partResult.unit, result)) {
+        anyPartHasDeclarations = true;
+      }
+    }
+
+    await _computePartDirectiveErrors(
+        result, collector, hasDeclarations || anyPartHasDeclarations);
+  }
+
   Future<void> _addPartDirectiveErrorForMember({
     @required ResolvedUnitResult result,
     @required DiagnosticCollector collector,

tools/analyzer_plugin/playground/web/invalid_generated_part_filename_parent.dart

@@ -0,0 +1,6 @@
+library invalid_generated_part_filename;
+
+import 'package:over_react/over_react.dart';
+part 'invalid_gnerated_part_filename_parent.over_react.g.dart';
+
+part 'invalid_generated_part_filename_part.dart';

tools/analyzer_plugin/playground/web/invalid_generated_part_filename_part.dart

@@ -0,0 +1,11 @@
+//part 'invaid_generated_part_filename_part.over_react.g.dart';
+part of invalid_generated_part_filename;
+
+UiFactory<FooProps> Foo = _$Foo; // ignore: undefined_identifier
+
+mixin FooProps on UiProps {}
+
+class FooComponent extends UiComponent2<FooProps> {
+  @override
+  render() {}
+}

tools/analyzer_plugin/playground/web/invalid_generated_part_filename.dart → tools/analyzer_plugin/playground/web/invalid_generated_part_filename_standalone.dart

@@ -1,6 +1,6 @@
 import 'package:over_react/over_react.dart';
 
-part 'invalid_generated_part_filename.over_react.g.dart';
+part 'invalid_generated_pat_filename_standalone.over_react.g.dart';
 
 UiFactory<FooProps> Foo = _$Foo; // ignore: undefined_identifier