Add ability to filter analzyer results on a set of paths

.github/workflows/dart_mcp_server.yaml

@@ -5,17 +5,17 @@ on:
   # Run CI on all PRs (against any branch) and on pushes to the main branch.
   pull_request:
     paths:
-      - '.github/workflows/dart_mcp_server.yaml'
-      - 'pkgs/dart_mcp_server/**'
-      - 'pkgs/dart_mcp/**'
+      - ".github/workflows/dart_mcp_server.yaml"
+      - "pkgs/dart_mcp_server/**"
+      - "pkgs/dart_mcp/**"
   push:
-    branches: [ main ]
+    branches: [main]
     paths:
-      - '.github/workflows/dart_mcp_server.yaml'
-      - 'pkgs/dart_mcp_server/**'
-      - 'pkgs/dart_mcp/**'
+      - ".github/workflows/dart_mcp_server.yaml"
+      - "pkgs/dart_mcp_server/**"
+      - "pkgs/dart_mcp/**"
   schedule:
-    - cron: '0 0 * * 0' # weekly
+    - cron: "0 0 * * 0" # weekly
 
 defaults:
   run:
@@ -64,6 +64,6 @@ jobs:
 
       # If this fails, you need to run 'dart tool/update_readme.dart'.
       - run: dart tool/update_readme.dart
-      - run: git diff --exit-code README.md
+      - run: git diff --exit-code README.md || (echo 'README.md needs to be updated. Run "dart tool/update_readme.dart"' && false)
 
       - run: dart test

pkgs/dart_mcp_server/CHANGELOG.md

@@ -12,6 +12,7 @@
   tends to hide nested text widgets which makes it difficult to find widgets
   based on their text values.
 * Add an `--exclude-tool` command line flag to exclude tools by name.
+* Add the abillity to limit the output of `analyze_files` to a set of paths.
 
 # 0.1.0 (Dart SDK 3.9.0)
 

pkgs/dart_mcp_server/README.md

@@ -151,7 +151,7 @@ For more information, see the official VS Code documentation for
 | `run_tests` | Run tests | Run Dart or Flutter tests with an agent centric UX. ALWAYS use instead of `dart test` or `flutter test` shell commands. |
 | `create_project` | Create project | Creates a new Dart or Flutter project. |
 | `pub` | pub | Runs a pub command for the given project roots, like `dart pub get` or `flutter pub add`. |
-| `analyze_files` | Analyze projects | Analyzes the entire project for errors. |
+| `analyze_files` | Analyze projects | Analyzes specific paths, or the entire project, for errors. |
 | `resolve_workspace_symbol` | Project search | Look up a symbol or symbols in all workspaces by name. Can be used to validate that a symbol exists or discover small spelling mistakes, since the search is fuzzy. |
 | `signature_help` | Signature help | Get signature help for an API being used at a given cursor position in a file. |
 | `hover` | Hover information | Get hover information at a given cursor position in a file. This can include documentation, type information, etc for the text at that position. |

pkgs/dart_mcp_server/lib/src/mixins/analyzer.dart

@@ -14,15 +14,17 @@ import 'package:meta/meta.dart';
 
 import '../lsp/wire_format.dart';
 import '../utils/analytics.dart';
+import '../utils/cli_utils.dart';
 import '../utils/constants.dart';
+import '../utils/file_system.dart';
 import '../utils/sdk.dart';
 
 /// Mix this in to any MCPServer to add support for analyzing Dart projects.
 ///
 /// The MCPServer must already have the [ToolsSupport] and [LoggingSupport]
 /// mixins applied.
 base mixin DartAnalyzerSupport
-    on ToolsSupport, LoggingSupport, RootsTrackingSupport
+    on ToolsSupport, LoggingSupport, RootsTrackingSupport, FileSystemSupport
     implements SdkSupport {
   /// The LSP server connection for the analysis server.
   Peer? _lspConnection;
@@ -249,8 +251,54 @@ base mixin DartAnalyzerSupport
     final errorResult = await _ensurePrerequisites(request);
     if (errorResult != null) return errorResult;
 
+    var rootConfigs = (request.arguments?[ParameterNames.roots] as List?)
+        ?.cast<Map<String, Object?>>();
+    final allRoots = await roots;
+
+    if (rootConfigs != null && rootConfigs.isEmpty) {
+      // Have to have at least one root set.
+      return noRootsSetResponse;
+    }
+
+    // Default to use the known roots if none were specified.
+    rootConfigs ??= [
+      for (final root in allRoots) {ParameterNames.root: root.uri},
+    ];
+
+    final requestedUris = <Uri>{};
+    for (final rootConfig in rootConfigs) {
+      final validated = validateRootConfig(
+        rootConfig,
+        knownRoots: allRoots,
+        fileSystem: fileSystem,
+      );
+
+      if (validated.errorResult != null) {
+        return errorResult!;
+      }
+
+      final rootUri = Uri.parse(validated.root!.uri);
+
+      if (validated.paths != null && validated.paths!.isNotEmpty) {
+        for (final path in validated.paths!) {
+          requestedUris.add(rootUri.resolve(path));
+        }
+      } else {
+        requestedUris.add(rootUri);
+      }
+    }
+
+    final entries = diagnostics.entries.where((entry) {
+      final entryPath = entry.key.toFilePath();
+      return requestedUris.any((uri) {
+        final requestedPath = uri.toFilePath();
+        return fileSystem.path.equals(requestedPath, entryPath) ||
+            fileSystem.path.isWithin(requestedPath, entryPath);
+      });
+    });
+
     final messages = <Content>[];
-    for (var entry in diagnostics.entries) {
+    for (var entry in entries) {
       for (var diagnostic in entry.value) {
         final diagnosticJson = diagnostic.toJson();
         diagnosticJson[ParameterNames.uri] = entry.key.toString();
@@ -411,8 +459,10 @@ base mixin DartAnalyzerSupport
   @visibleForTesting
   static final analyzeFilesTool = Tool(
     name: 'analyze_files',
-    description: 'Analyzes the entire project for errors.',
-    inputSchema: Schema.object(),
+    description: 'Analyzes specific paths, or the entire project, for errors.',
+    inputSchema: Schema.object(
+      properties: {ParameterNames.roots: rootsSchema(supportsPaths: true)},
+    ),
     annotations: ToolAnnotations(title: 'Analyze projects', readOnlyHint: true),
   );
 

pkgs/dart_mcp_server/lib/src/server.dart

@@ -36,8 +36,8 @@ final class DartMCPServer extends MCPServer
         ResourcesSupport,
         RootsTrackingSupport,
         RootsFallbackSupport,
-        DartAnalyzerSupport,
         DashCliSupport,
+        DartAnalyzerSupport,
         PubSupport,
         PubDevSupport,
         DartToolingDaemonSupport,

pkgs/dart_mcp_server/lib/src/utils/cli_utils.dart

@@ -252,6 +252,105 @@ Future<CallToolResult> runCommandInRoot(
   );
 }
 
+/// Validates a root argument given via [rootConfig], ensuring that it falls
+/// under one of the [knownRoots], and that all `paths` arguments are also under
+/// the given root.
+///
+/// Returns a root on success, equal to the given root (but this could be a
+/// subdirectory of one of the [knownRoots]), as well as any paths that were
+/// validated.
+///
+/// If no [ParameterNames.paths] are provided, then the [defaultPaths] will be
+/// used, if present. Otherwise no paths are validated or will be returned.
+///
+/// On failure, returns a [CallToolResult].
+({Root? root, List<String>? paths, CallToolResult? errorResult})
+validateRootConfig(
+  Map<String, Object?>? rootConfig, {
+  List<String>? defaultPaths,
+  required FileSystem fileSystem,
+  required List<Root> knownRoots,
+}) {
+  final rootUriString = rootConfig?[ParameterNames.root] as String?;
+  if (rootUriString == null) {
+    // This shouldn't happen based on the schema, but handle defensively.
+    return (
+      root: null,
+      paths: null,
+      errorResult: CallToolResult(
+        content: [
+          TextContent(text: 'Invalid root configuration: missing `root` key.'),
+        ],
+        isError: true,
+      )..failureReason ??= CallToolFailureReason.noRootGiven,
+    );
+  }
+  final rootUri = Uri.parse(rootUriString);
+  if (rootUri.scheme != 'file') {
+    return (
+      root: null,
+      paths: null,
+      errorResult: CallToolResult(
+        content: [
+          TextContent(
+            text:
+                'Only file scheme uris are allowed for roots, but got '
+                '$rootUri',
+          ),
+        ],
+        isError: true,
+      )..failureReason ??= CallToolFailureReason.invalidRootScheme,
+    );
+  }
+
+  final knownRoot = knownRoots.firstWhereOrNull(
+    (root) => _isUnderRoot(root, rootUriString, fileSystem),
+  );
+  if (knownRoot == null) {
+    return (
+      root: null,
+      paths: null,
+      errorResult: CallToolResult(
+        content: [
+          TextContent(
+            text:
+                'Invalid root $rootUriString, must be under one of the '
+                'registered project roots:\n\n${knownRoots.join('\n')}',
+          ),
+        ],
+        isError: true,
+      )..failureReason ??= CallToolFailureReason.invalidRootPath,
+    );
+  }
+  final root = Root(uri: rootUriString);
+
+  final paths =
+      (rootConfig?[ParameterNames.paths] as List?)?.cast<String>() ??
+      defaultPaths;
+  if (paths != null) {
+    final invalidPaths = paths.where(
+      (path) => !_isUnderRoot(root, path, fileSystem),
+    );
+    if (invalidPaths.isNotEmpty) {
+      return (
+        root: null,
+        paths: null,
+        errorResult: CallToolResult(
+          content: [
+            TextContent(
+              text:
+                  'Paths are not allowed to escape their project root:\n'
+                  '${invalidPaths.join('\n')}',
+            ),
+          ],
+          isError: true,
+        )..failureReason ??= CallToolFailureReason.invalidPath,
+      );
+    }
+  }
+  return (root: root, paths: paths, errorResult: null);
+}
+
 /// Returns 'dart' or 'flutter' based on the pubspec contents.
 ///
 /// Throws an [ArgumentError] if there is no pubspec.

pkgs/dart_mcp_server/test/test_harness.dart

@@ -173,7 +173,7 @@ class TestHarness {
     final result = await mcpServerConnection.callTool(request);
     expect(
       result.isError,
-      expectError ? true : isNot(true),
+      expectError ? true : isNot(isTrue),
       reason: result.content.join('\n'),
     );
     return result;
@@ -185,11 +185,12 @@ class TestHarness {
   Future<CallToolResult> callToolWithRetry(
     CallToolRequest request, {
     int maxTries = 5,
+    bool expectError = false,
   }) async {
     var tryCount = 0;
     while (true) {
       try {
-        return await callTool(request);
+        return await callTool(request, expectError: expectError);
       } catch (_) {
         if (tryCount++ >= maxTries) rethrow;
       }