feat: add experimental monorepo support for check-unused-code (#659)

* feat: add experimental monorepo support for check-unused-code

* fix: analyze all not analyzed files if in monorepo mode

* fix: fix how context folders are resolved

* chore: update changelog

* chore: fix test and update the docs

* docs: add info about limitations

* docs: add no-congratulate flag

Author: incendial

CHANGELOG.md

@@ -8,6 +8,7 @@
 * fix: make `check-unused-l10n` also cover supertype member calls.
 * fix: cyclomatic complexity calculation for functions with internal lambdas.
 * chore: restrict `analyzer` version to `>=2.4.0 <3.3.0`.
+* feat: support monorepos for `check-unused-code` command.
 
 ## 4.10.0-dev.2
 

lib/src/analyzers/unused_code_analyzer/unused_code_analyzer.dart

@@ -89,7 +89,9 @@ class UnusedCodeAnalyzer {
       }
     }
 
-    codeUsages.exports.forEach(publicCode.remove);
+    if (!config.isMonorepo) {
+      codeUsages.exports.forEach(publicCode.remove);
+    }
 
     return _getReports(codeUsages, publicCode, rootFolder);
   }
@@ -115,10 +117,12 @@ class UnusedCodeAnalyzer {
     String rootFolder,
     Iterable<Glob> excludes,
   ) {
-    final contextFolders = folders
-        .where((path) => normalize(join(rootFolder, path))
-            .startsWith(context.contextRoot.root.path))
-        .toList();
+    final contextFolders = folders.where((path) {
+      final newPath = normalize(join(rootFolder, path));
+
+      return newPath == context.contextRoot.root.path ||
+          context.contextRoot.root.path.startsWith('$newPath/');
+    }).toList();
 
     return extractDartFilesFromFolders(contextFolders, rootFolder, excludes);
   }

lib/src/analyzers/unused_code_analyzer/unused_code_config.dart

@@ -4,10 +4,12 @@ import '../../config_builder/models/analysis_options.dart';
 class UnusedCodeConfig {
   final Iterable<String> excludePatterns;
   final Iterable<String> analyzerExcludePatterns;
+  final bool isMonorepo;
 
   const UnusedCodeConfig({
     required this.excludePatterns,
     required this.analyzerExcludePatterns,
+    required this.isMonorepo,
   });
 
   /// Creates the config from analysis [options].
@@ -16,13 +18,18 @@ class UnusedCodeConfig {
         excludePatterns: const [],
         analyzerExcludePatterns:
             options.readIterableOfString(['analyzer', 'exclude']),
+        isMonorepo: false,
       );
 
   /// Creates the config from cli args.
-  factory UnusedCodeConfig.fromArgs(Iterable<String> excludePatterns) =>
+  factory UnusedCodeConfig.fromArgs(
+    Iterable<String> excludePatterns, {
+    required bool isMonorepo,
+  }) =>
       UnusedCodeConfig(
         excludePatterns: excludePatterns,
         analyzerExcludePatterns: const [],
+        isMonorepo: isMonorepo,
       );
 
   /// Merges two configs into a single one.
@@ -35,5 +42,6 @@ class UnusedCodeConfig {
           ...analyzerExcludePatterns,
           ...overrides.analyzerExcludePatterns,
         },
+        isMonorepo: isMonorepo || overrides.isMonorepo,
       );
 }

lib/src/cli/cli_runner.dart

@@ -37,16 +37,16 @@ class CliRunner extends CommandRunner<void> {
   /// Main entry point for running a command
   @override
   Future<void> run(Iterable<String> args) async {
-    final results = parse(args);
-    final showVersion = results[FlagNames.version] as bool;
+    try {
+      final results = parse(args);
+      final showVersion = results[FlagNames.version] as bool;
 
-    if (showVersion) {
-      _output.writeln('Dart Code Metrics version: $packageVersion');
+      if (showVersion) {
+        _output.writeln('Dart Code Metrics version: $packageVersion');
 
-      return;
-    }
+        return;
+      }
 
-    try {
       await super.run(_addDefaultCommand(args));
     } on UsageException catch (e) {
       _output

lib/src/cli/commands/check_unused_code_command.dart

@@ -31,10 +31,13 @@ class CheckUnusedCodeCommand extends BaseCommand {
     final folders = argResults.rest;
     final excludePath = argResults[FlagNames.exclude] as String;
     final reporterName = argResults[FlagNames.reporter] as String;
-
+    final isMonorepo = argResults[FlagNames.isMonorepo] as bool;
     final noCongratulate = argResults[FlagNames.noCongratulate] as bool;
 
-    final config = ConfigBuilder.getUnusedCodeConfigFromArgs([excludePath]);
+    final config = ConfigBuilder.getUnusedCodeConfigFromArgs(
+      [excludePath],
+      isMonorepo: isMonorepo,
+    );
 
     final unusedCodeResult = await _analyzer.runCliAnalysis(
       folders,
@@ -63,6 +66,7 @@ class CheckUnusedCodeCommand extends BaseCommand {
   void _addFlags() {
     _usesReporterOption();
     addCommonFlags();
+    _usesIsMonorepoOption();
     _usesExitOption();
   }
 
@@ -82,6 +86,15 @@ class CheckUnusedCodeCommand extends BaseCommand {
       );
   }
 
+  void _usesIsMonorepoOption() {
+    argParser
+      ..addSeparator('')
+      ..addFlag(
+        FlagNames.isMonorepo,
+        help: 'Treats all exported code as unused by default.',
+      );
+  }
+
   void _usesExitOption() {
     argParser
       ..addSeparator('')

lib/src/cli/models/flag_names.dart

@@ -11,6 +11,7 @@ class FlagNames {
   static const reporter = 'reporter';
   static const rootFolder = 'root-folder';
   static const sdkPath = 'sdk-path';
+  static const isMonorepo = 'monorepo';
   static const version = 'version';
 
   static const consoleReporter = ConsoleReporter.id;

lib/src/config_builder/config_builder.dart

@@ -92,9 +92,10 @@ class ConfigBuilder {
 
   /// Creates a raw unused code config from given [excludePatterns].
   static UnusedCodeConfig getUnusedCodeConfigFromArgs(
-    Iterable<String> excludePatterns,
-  ) =>
-      UnusedCodeConfig.fromArgs(excludePatterns);
+    Iterable<String> excludePatterns, {
+    required bool isMonorepo,
+  }) =>
+      UnusedCodeConfig.fromArgs(excludePatterns, isMonorepo: isMonorepo);
 
   /// Creates a raw unused code config from given [options].
   static UnusedCodeConfig getUnusedCodeConfigFromOption(

test/src/analyzers/unused_code_analyzer/unused_code_analyzer_test.dart

@@ -151,4 +151,5 @@ UnusedCodeConfig _createConfig({
     UnusedCodeConfig(
       excludePatterns: const [],
       analyzerExcludePatterns: analyzerExcludePatterns,
+      isMonorepo: false,
     );

test/src/cli/commands/check_unused_code_command_test.dart

@@ -22,6 +22,9 @@ const _usage = 'Check unused code in *.dart files.\n'
     "    --no-congratulate                             Don't show output even when there are no issues.\n"
     '\n'
     '\n'
+    '    --[no-]monorepo                               Treats all exported code as unused by default.\n'
+    '\n'
+    '\n'
     '    --[no-]fatal-unused                           Treat find unused file as fatal.\n'
     '\n'
     'Run "metrics help" to see global options.';

website/docs/cli/check-unused-code.md

@@ -2,6 +2,8 @@
 
 Checks unused classes, functions, top level variables, extensions, enums, mixins and type aliases.
 
+**Note:** current implementation doesn't check for particular class methods usage. Also, it treats code, that is imported with not named conditional imports as unused. This will be fixed in the future releases.
+
 To execute the command, run
 
 ```sh
@@ -31,9 +33,19 @@ Usage: metrics check-unused-code [arguments] <directories>
                                                   (defaults to "{/**.g.dart,/**.template.dart}")
 
 
-    --[no-]fatal-unused                           Treat find unused l10n as fatal.
+    --no-congratulate                             Don't show output even when there are no issues.
+
+
+    --[no-]monorepo                               Treats all exported code as unused by default.
+
+
+    --[no-]fatal-unused                           Treat find unused file as fatal.
 ```
 
+## Monorepo support
+
+By default the command treats all code that exported from the package as used. To disable this behavior use `--monorepo` flag. This might be useful when all the packages in your repository only unused inside this repository and not published to pub.
+
 ## Output example {#output-example}
 
 ### Console {#console}