feat: validate "melos exec" is not used in "run" along with "exec" (#438

)

Co-authored-by: Gabriel Terwesten <gabriel@terwesten.net>

packages/melos/lib/src/scripts.dart

@@ -24,6 +24,9 @@ import 'common/utils.dart';
 import 'common/validation.dart';
 import 'package.dart';
 
+// https://regex101.com/r/44dzaz/1
+final _leadingMelosExecRegExp = RegExp(r'^\s*melos\s+exec');
+
 /// Scripts to be executed before/after a melos command.
 class LifecycleHook {
   LifecycleHook._({required this.pre, required this.post});
@@ -83,6 +86,14 @@ class Scripts extends MapView<String, Script> {
     );
   }
 
+  /// Validates the scripts. Throws a [MelosConfigException] if any script is
+  /// invalid.
+  void validate() {
+    for (final script in values) {
+      script.validate();
+    }
+  }
+
   Map<Object?, Object?> toJson() {
     return {
       for (final entry in entries) entry.key: entry.value.toJson(),
@@ -300,6 +311,21 @@ class Script {
     return run;
   }
 
+  /// Validates the script. Throws a [MelosConfigException] if the script is
+  /// invalid.
+  void validate() {
+    if (exec != null && run.startsWith(_leadingMelosExecRegExp)) {
+      throw MelosConfigException(
+        'Do not use "melos exec" in "run" when also providing options in '
+        '"exec". In this case the script in "run" is already being executed by '
+        '"melos exec".\n'
+        'For more information, see https://melos.invertase.dev/configuration/scripts#scriptsexec.\n'
+        '\n'
+        '    run: $run',
+      );
+    }
+  }
+
   Map<Object?, Object?> toJson() {
     return {
       'name': name,

packages/melos/lib/src/workspace_configs.dart

@@ -860,6 +860,8 @@ You must have one of the following to be a valid Melos workspace:
         'repository must be specified if commands/version/linkToCommits is true',
       );
     }
+
+    scripts.validate();
   }
 
   /// Validates the physical workspace on the file system.

packages/melos/test/workspace_config_test.dart

@@ -453,6 +453,23 @@ void main() {
           throwsA(isA<MelosConfigException>()),
         );
       });
+
+      test('throws when using "melos exec" in "run" and specifying "exec"', () {
+        expect(
+          () => Scripts.fromYaml(
+            createYamlMap({
+              'a': {
+                'run': 'melos exec a',
+                'exec': {
+                  'concurrency': 1,
+                },
+              },
+            }),
+            workspacePath: testWorkspacePath,
+          ).validate(),
+          throwsA(isA<MelosConfigException>()),
+        );
+      });
     });
   });