From c0409773d99d3a8c8cf2d70d2c163dfde46ba388 Mon Sep 17 00:00:00 2001
From: bspinner <4580497+bspinner@users.noreply.github.com>
Date: Tue, 29 Oct 2024 14:10:11 +0100
Subject: [PATCH 1/2] Executes scripts with same dart/melos combination as
 currently running

---
 packages/melos/lib/src/scripts.dart | 45 ++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/packages/melos/lib/src/scripts.dart b/packages/melos/lib/src/scripts.dart
index 8d172b29..20221df6 100644
--- a/packages/melos/lib/src/scripts.dart
+++ b/packages/melos/lib/src/scripts.dart
@@ -3,6 +3,7 @@ import 'dart:collection';
 import 'package:collection/collection.dart';
 import 'package:meta/meta.dart';
 
+import 'common/platform.dart';
 import 'common/utils.dart';
 import 'common/validation.dart';
 import 'package.dart';
@@ -318,7 +319,8 @@ class Script {
     if (exec == null) {
       return scriptCommand;
     } else {
-      final execCommand = ['melos', 'exec'];
+      /// `dart melos.dart exec` or `melos exec` with absolute paths
+      final execCommand = [..._determineMelosExecutablePaths(), 'exec'];
 
       if (exec.concurrency != null) {
         execCommand.addAll(['--concurrency', '${exec.concurrency}']);
@@ -338,6 +340,47 @@ class Script {
     }
   }
 
+  /// Identifies path of currently running melos and reuses it for nested script execution.
+  ///
+  /// Starting melos by just calling `melos` via shell
+  /// would use the first found binary found in `$PATH`,
+  /// i.e. usually the globally activated version. If there is one.
+  ///
+  /// This can cause issues when melos is started with `dart run melos`,
+  /// which will prefer the melos version specified via (dev_)dependencies.
+  /// So the initially started melos binary/script and the one used for melos script execution
+  /// could differ.
+  ///
+  /// Besides ensuring starting the same melos as currently running,
+  /// this furthermore enables use of melos in environments
+  /// where `.pub-cache/bin` should/must not be put in `$PATH`.
+  List<String> _determineMelosExecutablePaths() {
+    final currentExecutablePathString = currentPlatform.resolvedExecutable;
+    final currentExecutablePathUri = Uri.file(currentExecutablePathString);
+    if (!currentExecutablePathUri.isAbsolute) {
+      throw 'Got invalid, unsupported or relative path to running executable. Expected absolute path.';
+    }
+
+    final currentScriptPathUri = currentPlatform.script;
+    final currentScriptPathString = currentScriptPathUri.toFilePath();
+    if (!currentScriptPathString.isEmpty && !currentScriptPathUri.isAbsolute) {
+      throw 'Got invalid, unsupported or relative path to melos. Expected absolute path.';
+    }
+
+    // Determine if melos is running as script or compiled binary
+    final isScriptPathAvailable = !currentScriptPathString.isEmpty;
+    final isCompiledMelosRunning =
+        currentExecutablePathUri == currentScriptPathUri;
+
+    if (!isScriptPathAvailable || isCompiledMelosRunning) {
+      return [currentExecutablePathString];
+    }
+
+    // currentExecutablePathString => path to dart binary
+    // currentScriptPathUri => path to melos.dart
+    return [currentExecutablePathString, currentScriptPathString];
+  }
+
   /// Validates the script. Throws a [MelosConfigException] if the script is
   /// invalid.
   void validate() {

From c1f5d002e054ad9eb0a1c63ef0d5e593dfbfa0e6 Mon Sep 17 00:00:00 2001
From: bspinner <4580497+bspinner@users.noreply.github.com>
Date: Tue, 29 Oct 2024 14:15:37 +0100
Subject: [PATCH 2/2] Fixes analysis issues

---
 packages/melos/lib/src/scripts.dart | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/packages/melos/lib/src/scripts.dart b/packages/melos/lib/src/scripts.dart
index 20221df6..80205a8b 100644
--- a/packages/melos/lib/src/scripts.dart
+++ b/packages/melos/lib/src/scripts.dart
@@ -340,7 +340,8 @@ class Script {
     }
   }
 
-  /// Identifies path of currently running melos and reuses it for nested script execution.
+  /// Identifies path of currently running melos and reuses it
+  /// for nested script execution.
   ///
   /// Starting melos by just calling `melos` via shell
   /// would use the first found binary found in `$PATH`,
@@ -352,23 +353,28 @@ class Script {
   /// could differ.
   ///
   /// Besides ensuring starting the same melos as currently running,
-  /// this furthermore enables use of melos in environments
-  /// where `.pub-cache/bin` should/must not be put in `$PATH`.
+  /// this furthermore enables use of melos in environments where
+  /// `.pub-cache/bin` should/must not be put in `$PATH`.
   List<String> _determineMelosExecutablePaths() {
     final currentExecutablePathString = currentPlatform.resolvedExecutable;
     final currentExecutablePathUri = Uri.file(currentExecutablePathString);
     if (!currentExecutablePathUri.isAbsolute) {
-      throw 'Got invalid, unsupported or relative path to running executable. Expected absolute path.';
+      throw FormatException(
+          'Got invalid, unsupported or relative path to running executable.'
+          'Expected absolute path.');
     }
 
     final currentScriptPathUri = currentPlatform.script;
     final currentScriptPathString = currentScriptPathUri.toFilePath();
-    if (!currentScriptPathString.isEmpty && !currentScriptPathUri.isAbsolute) {
-      throw 'Got invalid, unsupported or relative path to melos. Expected absolute path.';
+    if (currentScriptPathString.isNotEmpty &&
+        !currentScriptPathUri.isAbsolute) {
+      throw FormatException(
+          'Got invalid, unsupported or relative path to melos.'
+          'Expected absolute path.');
     }
 
     // Determine if melos is running as script or compiled binary
-    final isScriptPathAvailable = !currentScriptPathString.isEmpty;
+    final isScriptPathAvailable = currentScriptPathString.isNotEmpty;
     final isCompiledMelosRunning =
         currentExecutablePathUri == currentScriptPathUri;