From 42a368bcd706b75c930e2ab337ed344f03d5dae5 Mon Sep 17 00:00:00 2001
From: Damien Le Berrigaud <git@itsdamo.com>
Date: Wed, 22 Nov 2023 13:37:40 -0700
Subject: [PATCH] Add support for melos mono-repo.

---
 .../cycle_detector_runner.dart                | 40 ++++++++++++++-----
 lib/cycle_detection/melos_paths.dart          | 26 ++++++++++++
 2 files changed, 55 insertions(+), 11 deletions(-)
 create mode 100644 lib/cycle_detection/melos_paths.dart

diff --git a/lib/cycle_detection/cycle_detector_runner.dart b/lib/cycle_detection/cycle_detector_runner.dart
index ef48d75..81c7b3f 100644
--- a/lib/cycle_detection/cycle_detector_runner.dart
+++ b/lib/cycle_detection/cycle_detector_runner.dart
@@ -1,6 +1,7 @@
 import 'dart:io';
 
 import 'package:args/args.dart';
+import 'package:cyclic_dependency_checks/cycle_detection/melos_paths.dart';
 
 import 'cycle_detector.dart';
 import 'module_dependency_graph.dart';
@@ -24,6 +25,7 @@ class CycleDetectorRunner {
   Future<bool> run(List<String> args) async {
     final parser = ArgParser()
       ..addOption('path', abbr: 'p')
+      ..addOption('mono-repo', abbr: 'm')
       ..addOption('max-depth', abbr: 'd');
 
     final parsedArgs = parser.tryParse(args);
@@ -31,18 +33,40 @@ class CycleDetectorRunner {
       return false;
     }
 
-    final path = parsedArgs.getString('path', fallback: '.');
-    final maxDepth = parsedArgs.tryGetInt('max-depth');
+    final pathArg = parsedArgs['path'];
+    final monorepoArg = parsedArgs['mono-repo'];
+    final maxDepthArg = parsedArgs.tryGetInt('max-depth');
 
+    final inferredPaths = await _tryGetPaths(pathArg, monorepoArg);
+    if (inferredPaths == null) {
+      printer.err('Failed to infer path from arguments, only one of path or monorepo can be specified');
+      return false;
+    }
+
+    for (var path in inferredPaths) {
+      _runForPath(path, maxDepthArg);
+    }
+
+    return true;
+  }
+
+  Future<List<String>?> _tryGetPaths(String? packagePath, String? monorepoPath) async =>
+    switch ((packagePath, monorepoPath)) {
+      (null, null) => ['.'],
+      (String p, null) => [p],
+      (null, String p) => await MelosPaths.tryGet(p),
+      (_, _) => null,
+    };
+
+  Future _runForPath(String path, int? maxDepth) async {
     final stopwatch = Stopwatch()..start();
     final cycles = await detector.detect(path, maxDepth: maxDepth);
-
     stopwatch.stop();
 
     final formattedTime = stopwatch.elapsed.toString().substring(0, 11);
 
     if (cycles.isNotEmpty) {
-      printer.err('Detected cycles after ${formattedTime}');
+      printer.err('[$path] Detected cycles after ${formattedTime}');
 
       for (final cycle in cycles) {
         printer.err(cycle.path().join(' -> '));
@@ -51,9 +75,7 @@ class CycleDetectorRunner {
       return false;
     }
 
-    printer.out('No import cycles were detected after ${formattedTime}');
-
-    return true;
+    printer.out('[$path] No cycles detected after ${formattedTime}');
   }
 }
 
@@ -70,10 +92,6 @@ extension _SafeParse on ArgParser {
 }
 
 extension _TypeSafeArgs on ArgResults {
-  String getString(String name, {required String fallback}) {
-    return this[name] ?? fallback;
-  }
-
   int? tryGetInt(String name) {
     final value = this[name];
 
diff --git a/lib/cycle_detection/melos_paths.dart b/lib/cycle_detection/melos_paths.dart
new file mode 100644
index 0000000..38524fb
--- /dev/null
+++ b/lib/cycle_detection/melos_paths.dart
@@ -0,0 +1,26 @@
+import 'dart:io';
+import 'package:path/path.dart' as path;
+
+
+final class MelosPaths {
+  static Future<List<String>?> tryGet(String monorepoPath) async {
+    final listResult = await Process.run(
+      'melos',
+      ['list', '-p'],
+      workingDirectory: monorepoPath,
+    );
+
+    if (listResult.exitCode != 0) {
+      return null;
+    }
+
+    final output = listResult.stdout as String;
+    final currentDir = Directory.current;
+
+    return output
+        .split('\n')
+        .where((p) => p.trim().length > 0)
+        .map((p) => path.relative(p, from: currentDir.absolute.path))
+        .toList();
+  }
+}